About the Author

Intrepid zoologist Dr Arik Kershenbaum is the world-leading expert in animal vocal communication and has roamed the wilds of Europe, North America, the Middle East and Southeast Asia for over a decade, working to decipher it. He is a college lecturer and fellow at Girton College, University of Cambridge, and has published more than thirty academic publications. His previous book, The Zoologist’s Guide to the Galaxy, was a Times/Sunday Times Book of the Year and was published in eleven languages.

Arik Kershenbaum

WHY ANIMALS TALK

The New Science of Animal Communication

To my dog, Darwin Kershenbaum, who at sixteen years old, reached the end of his natural life and slipped away peacefully at home, surrounded by all his family.

אַל תַּשְׁלִיכֵֽנוּ לְעֵת זִקְנָה כִּכְלוֹת כֹּחֵֽנוּ אַל תַּעַזְבֵֽנוּ

‘Do not cast us away in our old age; when our strength fails, do not abandon us.’

Illustrations

Introduction

1. Alice’s Adventures in Wonderland, dodo. Wikipedia

2. ‘Rhapsody in Blue’ in musical notation. Wikipedia

3. ‘Rhapsody in Blue’ as a pure spectrogram. Arik Kershenbaum

4. ‘Rhapsody in Blue’ as a cartoon spectrogram. Arik Kershenbaum

5. ‘Born to be Wild’ as a cartoon spectrogram. Arik Kershenbaum

Wolf/Chapter 1

6. Wolf. Private collection

7. Observing wolves in YNP. Arik Kershenbaum

8. Child vs wolf spectrogram. Arik Kershenbaum

9. Angela vs wolf spectrogram. Arik Kershenbaum

10. Sikko the Arctic wolf at the UKWCT. Arik Kershenbaum

11. Russell’s circumplex model. Arik Kershenbaum

12. Lone-cohesion-chorus spectrograms. Arik Kershenbaum

13. European-sheepdog-Italian spectrograms. Arik Kershenbaum

Dolphin/Chapter 2

14. Dolphin. Private collection

15. Spinner dolphins’ spectrogram. Arik Kershenbaum

16. Dolphin clicks spectrogram. Arik Kershenbaum

17. Ten different dolphin whistles. Arik Kershenbaum

18. Mozart’s K265 sheet music and Parsons code. Arik Kershenbaum

19. Five signature dolphin whistles. Arik Kershenbaum

20. Arik with meerkat 1 and 2. Both Arik Kershenbaum

21. Sound experiment with dolphin 1, 2, 3 and 4. All Departamento de audiovisuales de Loro Parque

Parrot/Chapter 3

22. Parrot. Private collection

23. African grey parrots in cage. Arik Kershenbaum

24. Parrot squawk and whistle spectrogram. Arik Kershenbaum

25. African grey parrots calling spectrogram. Arik Kershenbaum

26. African grey parrots whistles. Arik Kershenbaum

27. M/R training. William Muñoz

28. Monk parakeets multi-family apartments. Wikipedia

29. Monk parakeet spectrograms. Arik Kershenbaum

Hyrax/Chapter 4

30. Hyrax. Arik Kershenbaum

31. Pair of hyraxes. Arik Kershenbaum

32. Hyrax foot. Arik Kershenbaum

33. Hyrax teeth. Arik Kershenbaum

34. Five hyrax notes spectrograms. Arik Kershenbaum

35. Two hyrax songs notes. Arik Kershenbaum

36. Hyrax mobbing. Arik Kershenbaum

37. Ariel shot of hyrax sites. Arik Kershenbaum

38. Canyon view. Arik Kershenbaum

Gibbon/Chapter 5

39. Gibbon. Private collection

40. Cao vit gibbon. Wikipedia

41. View over jungle. Arik Kershenbaum

42. Lar gibbon duet spectrogram. Arik Kershenbaum

43. Evolutionary family tree of the apes. Arik Kershenbaum

44. Twenty-seven lar gibbon sounds. Private collection

45. Hyrax syntax diagram. Arik Kershenbaum

46. Lar gibbon syntax diagram. Angela Dassow

47. Four music transition networks. Arik Kershenbaum

48. Transition diagrams of lar gibbon responses to a leopard, a snake and a tiger. All Angela Dassow

Chimpanzee/Chapter 6

49. Chimpanzee. Private collection

50. Chimpanzee pant-hoot spectrogram. Arik Kershenbaum

51. Chimpanzee barks spectrogram. Arik Kershenbaum

52. Chimpanzee barks vocalizations. Arik Kershenbaum

53. Lexigrams. Von Glasersfeld, E.

Human/Chapter 7

54. Humans. Wikipedia

55. Eating in the jungle. Arik Kershenbaum

56. Working with equipment in the jungle. Arik Kershenbaum

57. Explaining equipment in the jungle. Arik Kershenbaum

58. Language-concept graph. Arik Kershenbaum

59. Yao honey hunter. Claire Spottiswoode

60. Dogs and wolves participating in a cooperative challenge. Both Marshall-Pescini, S., Basin, C., & Range, F.

61. ‘Would you like some cheese?’ spectrogram. Arik Kershenbaum

Conclusion

62. Man with parrot cartoon. Hugh Lofting

1.

Introduction. Everybody’s talking … but no one says a word

Today, as it was 100,000 years ago, we humans are surrounded by animals and all the sounds that they make. By day, the screeching of crows, the howling of dogs (sometimes wolves, even), and clouds of songbirds with their contrasting and overlapping compositions. By night, a cacophony of crickets chirping, owls hooting, and foxes crying. It’s one of the oldest mysteries that has haunted humans since we began to ponder our own relationship with the natural world. What are all these animals saying? Perhaps they are talking much like we do? Or perhaps we are unique, and animals are chattering meaninglessly. Are we really the only animals on the planet to have a language? And if so, what is it that distinguishes our language, our information-packed and immensely powerful communication, from the confused and overpowering twittering of a flock of thousands of starlings? Why is it that the dance of bees, pointing their hive-mates to the best food sources, isn’t a language like our own? And can we be sure that a troop of chattering monkeys, angrily chastising the humans walking below their tree, aren’t really talking, the way we talk?

When we hear animals, what do we hear?

Ancient humans, living in a time much closer to nature, were surrounded by the sounds of creatures, some insignificant, some deadly. Before traffic noise became a constant hum, drowning out not just the gentle buzzing of insects, but masking even the dawn chorus of hundreds of birds, the world was filled with animal sounds. Could it be that all of the screeching, howling, and singing meant nothing at all? Even in prehistoric times, it was inevitable that we attempted to make sense of what we were hearing. And when the only yardstick we had for interpreting communication was our own language, then it was natural to assume that these animals were talking too. The singing of coyotes at night was not so different from our own songs around the campfire. The calling of birds to each other every morning no different from greeting our own family and neighbours upon waking. Certainly, the warning roar of a lion when you approach too close to her cubs is a message that is hard to misinterpret. Of course animals spoke! And therefore, our distant ancestors felt that animals had spirits like us, desires and ambitions like ours, and, no doubt, stories and tales to tell us. What culture does not have tales of talking animals? In the Bible, Balaam had a donkey that berated him for mistreating her. Icelandic mythology tells of Ratatoskr, a squirrel who is a messenger of the gods, scampering up and down the tree of life. And in Indian legend, Kindama the deer cursed a hunter for shooting him while he was mating.

Times have changed since that age full of legends of talking animals. We now cast a sceptical eye on the possibility that a grasshopper and an ant could have an argument about storing food for winter, as in Aesop’s fable. But who doesn’t believe that their pet dog or cat can tell them when it’s time to be fed, or time to go outside? And our appetite for stories about talking animals hasn’t diminished – from classic Disney movies like The Lion King to quasi-realistic novels like Watership Down and Wild Animals I Have Known. Our fascination with the possibility that animals might speak is partly because of them – we want to understand what is going through their minds – but also partly because of us. Do we have a deep need to believe that animals are not just mindless robots, but reflect our own existence in a simpler, perhaps more appealing life?

Or maybe animals do have something to say – something that we don’t yet understand. Many people believe so, but how do we find the tools to check whether this is the case? Philosophy and religion, intuition and common sense have, until recently, dominated our struggle to understand animals. On one hand, some philosophers (such as Immanuel Kant, more than 200 years ago) have declared quite unequivocally that animals cannot be talking meaningfully because they lack rationality. Religious leaders have tended to agree, because placing humans on a unique pedestal supports many religious narratives of the special place that humanity occupies at the pinnacle of all creation. On the other hand, we all feel that animals might have more to say – maybe even believe that they are talking to us. Neither approach has managed to give us a really satisfying resolution – there simply cannot be a single yes/no answer to such a question. Animal life is too complex, too varied, and there are so many complications and such diversity that generalizations rarely provide a complete picture. The robin in a tree leads a simpler life than the chimpanzee in the jungle – why should their communication be similar? The dolphin under the sea occupies an environment we struggle even to conceive of – simplistic comparisons with more familiar animals are unlikely to bring us much understanding. We need a more rigorous approach. If we don’t want to be blinded by our own desire to believe that animals are talking to us, or by our assumption that we are inherently superior to other animals, then we must seek the objective truth. Maybe animals talk. Maybe they don’t. We need to investigate.

Unfortunately, all our scientific advances haven’t brought us very far – at least, not until quite recently. By and large, scientists have been unwilling to address such questions as ‘What do animal noises mean?’ Following the lead of Renaissance philosopher René Descartes almost 400 years ago, science preferred to consider animals as lacking any internal mental experience, without cognitive states or cognitive needs. And so, I suppose the logic would go, with nothing in their minds, they have nothing to talk about. Descartes, in fact, described non-human animals as ‘automata’, i.e. robots. In a peculiar literary twist, illustrating how ignoring animal consciousness is fraught with problems, the term ‘robot’ was coined by Czech science-fiction writer Karel Čapek in his dystopian 1920 play R.U.R. But Čapek also wrote an incisive novel, The War with the Newts, in which humanity’s assumption that animals are no more than mindless automata eventually brings about its own destruction.

Even though some progress was made when experimental psychology emerged 150 years ago, scientists were still primarily interested in probing the workings of the brain as if it were a mysterious black box. By watching rats running around a maze, white-coated experimental psychologists studied how animals reacted to certain stimuli rather than questioning what they were thinking. Measuring how quickly – or how slowly – an animal learned that one button dispensed food while another button delivered an electric shock taught scientists that animals could learn, but gave no clues about why they learned. It seems obvious to us now – used as we are to TV nature documentaries – that the scientific study of animal behaviour should examine the ways animals behave in the wild, rather than being restricted to experiments in the lab. But the rationale was that, if animals were mere automata responding instinctively to any stimulus, then it should be possible to discover everything about them inside the lab. Probing – either with clever experiments using mazes and puzzles, or by placing electrodes in an animal’s brain to measure the electrical activity – should reveal ‘how animals work’, just as dismantling a car engine will tell you everything you need to know about internal combustion. Where was the error in this approach? Precisely in the preconception that animals must be fundamentally different from and simpler than humans – that animals must be robots. Whereas ancient cultures were happy to believe in cursing donkeys and messenger squirrels, the modern European philosophers of the last 400 years wanted to show that the entire universe – with the exception of humans, created as they were, in God’s image – could be reduced to a set of clockwork mechanical instructions. Thus was the idea that animals cannot talk ensconced in Western culture.

Twentieth-century science began to challenge these old ideas of human exceptionalism. Why must animals be so different from humans? We can’t simply assume that, because we appear to behave so differently from other animals, and seem to be capable of far more complex technological achievements, our fundamental makeup is therefore different. Humans, just like every other animal alive today, have been evolving for exactly the same length of time – 3,800 million years – and evolved from the same common ancestor as the rest of the animal kingdom. Placing humans and animals into an evolutionary context gave birth to a new science, one where people studied animal behaviour in the wild – after all, no animals evolved running around a scientist’s maze and pushing buttons, so why should we probe their inner workings in such an unnatural environment, rather than in the environment for which they are truly suited? In the 1920s and 1930s, two of the leaders in this new field, Nobel Prize winners Nico Tinbergen and Karl von Frisch, were fascinated by the way that bees forage, and this led von Frisch to his decoding of the honeybee dance ‘language’.fn1 At this point, a hundred years ago, the term ‘language’ hadn’t yet been well enough defined in itself, so no one worried too much whether the simple messages that one bee conveyed to the rest of the hive were really sophisticated enough to bear the same label as our expressive human language. But never mind – the curse had been broken. The idea that humans are the only creatures even capable of communicating with each other no longer seemed tenable. Maybe animals do speak after all. Importantly, this new science, dubbed ethology, considered animal behaviour in the context of evolution. That’s important because, rather than just describing how animals behave, it gave the explanations of ethologists a mechanism. Although Charles Darwin’s revolutionary theory of evolution had already been published for seventy years, the implications were still seeping through the scientific community: yes, an animal might have big horns or a loud roar, but could we explain why? Evolution by natural selection provided that ‘why’. As a result of focusing on the evolutionary mechanism for an animal’s behaviour, any conclusions we draw about talking animals cannot just be wishful thinking or romanticizing – animals behave in a particular way because it gives them an advantage: they can survive better, reproduce more, or raise their offspring more effectively. The evolutionary perspective helped to remove science from the shackles of the philosophical trap that for centuries held that science must always show humans to be superior.

The religious and philosophical belief that humans were superior and fundamentally different from other animals was strong and pervasive – not just in ancient times, but even today. There has been fierce resistance over the centuries, from Descartes and his religious reasons for thinking that animals lacked souls, to modern philosophers like Steven Pinker and Daniel Dennett, rejecting any claims that animals might possess something once considered unique to humans. But if talking is advantageous, if it serves the survival and reproductive needs of an animal, then we could expect that faculty to evolve. It’s as simple as that. The laws of evolution permit no dogma, neither that of philosophers nor that of religious leaders. The study of communication in bees by von Frisch in the 1920s opened the floodgates: since then, there has been an explosion of interest in how, why, and even what animals communicate to each other. Books and journals, conferences and degree courses abound – animal communication is a lively and fast-moving field of scientific research. We have excellent explanations now for the role of birdsong in attracting mates, the alarm calls of monkeys that warn of different kinds of predator, and we have a seemingly unending stream of mysteries to unlock too: Why do humpback whales sing? What are elephants telling each other with their deep rumbles, inaudible to the human ear? Are the complex swirling patterns of colour on the skin of reef squid really a kind of communication?

And yet (rather ironically) we scientists have done a poor job of communicating our own findings to the public. Many people still assume that ‘animal communication’ means some kind of telepathic connection with whales or horses. Let’s face it: we all want to believe we can talk to animals – even animal communication scientists like me. I’m guessing that not one of my colleagues hasn’t at some time dreamed of holding a sophisticated conversation with some species or other. So perhaps it’s not surprising that the advances in the scientific field, fascinating as they certainly are, look unimpressive compared with what we all want: we would like a computer to translate animals for us at the click of a button. It’s easy enough to find books on how to interpret your dog’s body language (a very important venture, of course) but much harder to find accessible explanations of why animals talk, and what information they really have to impart. We scientists haven’t done a good job of presenting just how much we really do know about what animals say. And we know a lot.

So here I am. My own research investigates the communication of wolves, dolphins, parrots, gibbons, and other species. What they say, why they say it, and how that message is wrapped up and transmitted to other animals. I can think of little that is more exciting, more interesting, and frankly more fun to study. My aim is not to tell you what animals are saying. My aim with this book is to bring you into the communicative lives of animals. What do animals say? A few different things – and it would be interesting to know what things they are. But to me, it is far, far more interesting to know why and how animals say these things, what drives animals to communicate the way they do, and what their communication says about who they are and how they came to be. If we can understand the why of the matter, then we can understand the animals in a more complete sense, rather than as mere translation. So, this is a very different book from anything else that’s been written about animal communication. Nonetheless, running through it is a deeper question that we’ve all pondered at some point. What is the connection between the way that we humans speak and the communication of other animals? Can science make a link between the two? Is there something fundamentally shared between human speech, and animal – for want of a better word – speech?

In my job, I’m outrageously fortunate to meet animals in the wild, in their own environment, in the jungle or the desert or underwater, far from any other human being, where I am the stranger and they are at home. That’s the only way to understand what makes animals the way they are. I’ll try to communicate some of that, because without a feel for what the life of an animal is like, any attempt to understand them is to understand a cardboard cutout of an animal. Behaviour in general is something that serves a goal – finding food, finding a mate, avoiding being eaten … To understand behaviour we first must understand the lifetime (i.e. evolutionary) goals that animals possess. What they need to do to be successful, and how that behaviour – communication behaviour, in our case – helps them in their quest to be successful.

But why do animals talk in the first place?

I once gave a public talk on dolphin communication, and a member of the audience asked me, ‘Is it possible that dolphins are telepathic?’ The inappropriate (if technically accurate) way to answer that question would have been, ‘No, of course not! There’s no such thing as telepathy’ (for an explanation of why not, see my previous book, The Zoologist’s Guide to the Galaxy). But my goal in science education is not to give technically accurate but inappropriate answers. In contrast to communicating to the public about other sciences, like physics or mathematics, in this field of animal communication our goal is not so much conveying facts as transmuting misconceptions. Misconceptions are rarely completely misguided, and more often require just a subtle change in the way that a concept is phrased to arrive at a more satisfying explanation. Why do people think dolphins are telepathic? What do people even think telepathy is? Literally, telepathy is the transmission of feelings over long distances. Surely this is just communication! When your dog looks at you with sad eyes and droopy ears, and you understand that it’s time for a walk, this is certainly communication – and communication without words. Telepathy? No, rather it is the very essence of communication itself. Changing the question, changing the perspective, can be as useful an educational technique as feeding information.

The first myth to remodel is that animals are furry (or feathery) little humans. If they were, then we would have no problem looking at their communication as something analogous to our own language – perhaps just a different language that simply needs to be learned, as we might learn Latin in school. But no, animals are not furry humans. They have evolved with very different needs from ours: different needs for learning about their environment, learning about the other animals around them, and passing information to those other animals. We think that there is nothing special about greeting someone in the street with the comment, ‘Turned out nice today’ (a translation for those non-British readers among you: this is an expression of pleasant surprise that it is not currently raining). But in fact, this uniquely British aphorism is a truly peculiar comment to pass between two strangers – conveying no useful or survival-enhancing information. As such, it tells us a lot about who we are as humans, and what our communicative needs are. We evolved to live in complex societies, where encountering strangers could offer serious opportunities – and serious dangers. Meeting someone in the street could end in a love affair or in a brutal mugging. Ritualized greetings such as ‘Turned out nice today’ can indicate our intentions to abide by society’s rules, and so help keep the wheels of society turning smoothly. However, can we really expect two rabbits, upon meeting each other, to exchange similar greetings? Or two dolphins? Well, perhaps we might. Clearly, it depends on the nature of their societies, and the way that they grease the wheels of social interactions. Which means we can’t understand animal communication without understanding animal societies. Certainly, we can’t assume that other animals will feel the need to make an irrelevant comment about an obvious meteorological fact upon passing each other, just because we do. It seems almost obvious that if we want to understand what animals are really saying, we have to begin by understanding how those individual animals relate to each other, what their societies are like, and why they should say anything at all.

For one thing, it’s clear that animals make a lot of noise, and that means they invest an awful lot of time and energy into being noisy. Evolution is economical – a behaviour that wastes energy is something that should put you at a disadvantage in the long term, so such a behaviour is likely to disappear from a population in a relatively small number of generations. Our ancestors were covered with fur like all other primates, but running across the savannah chasing antelope was a hot business, and so our fur-covered bodies were a burden, and we eventually became furless. If making sounds were a useless activity, you’d expect it to disappear as well. But vocal animals are everywhere, so there seems to be some kind of evolutionary benefit to all that noisemaking. More than that, vocal communication almost seems to define many animals. A robin that doesn’t sing isn’t much of a robin. A wolf that doesn’t howl isn’t much of a wolf. There’s something about the relationship between the noises that an animal makes, its lifestyle and its evolutionary history that makes these sounds fundamental to what each species really is. A wolf that doesn’t howl isn’t an inadequate wolf just because of our cultural assumption that wolves ‘must’ howl. Rather, a wolf that doesn’t howl is at a decided disadvantage – she can’t find her pack mates in the frozen Arctic or call to her mate to bring food to her cubs. A robin that doesn’t sing will find his territory overrun by other males who have no reason to stay away, or to suspect that these resources have already been claimed. It’s these evolutionary insights, only fully developed over the last fifty years or so, that can take us into the inner lives of these animals. If we know why animals talk, we can know what they say – that is, if they even mean anything at all.

Taking a sober scientific approach may not give us the answers we want. We might find that we will never be able to talk to the animals like Doctor Dolittle. Or we might find that we can talk to the animals, and that we humans aren’t so special after all. Most likely, the answer is somewhere in between. And bit by bit, scientists are getting closer to the real answers, the answers that describe how animals really are, rather than what we want them to be. This is a worthwhile exercise for anyone who is truly interested in the natural world. It is appealing to look at the wonders of nature – the colours of a flower, or the herds of millions of wildebeest on the savannah – and be content with just wonder, not understanding. Countless young children scream with delight at the antics of monkeys in a zoo – is it really necessary to understand why they behave as they do, as long as we can get enjoyment out of the behaviour itself? I think so. The physicist Richard Feynman once commented on the scientist’s view of wonder, comparing the artist’s fundamentally aesthetic view of the world to the mechanistic inclinations of the scientist. He said there were ‘All kinds of interesting questions which the science knowledge only adds to the excitement, the mystery and the awe of a flower. It only adds. I don’t understand how it subtracts.’1

I can appreciate the natural world aesthetically, perhaps even more so than many people, as I’m lucky enough to see more of it than most. I too tremble with awe at the earth shaking under the hooves of a limitless river of wildebeest. But on top of that aesthetic awe, I want to add an extra layer of wonder. I want to understand why the wildebeest congregate in such huge numbers. I don’t think that we need to believe that gorillas tell each other bedtime stories, or that dolphins exchange legends of creation myths, to have a powerful attraction to these animals for who and what they actually are.

Even if we discover that we will never talk to animals in the same way that we can talk to other humans, never hold a true conversation with a dolphin, still just by probing those possibilities we will find out why they live their lives the way they do. We will understand more about what talking really is, in species that for their own reasons talk but without language, and that discovery will also tell us a great deal about who we ourselves are as well. How humans might or might not be different from other animals has obsessed philosophers for millennia and obsesses us today as well. Are we just very clever apes? Are we something different entirely? What, if anything, do humans have that animals do not? Language would seem to be an answer to that question. We can tell stories, we have Shakespeare and J. K. Rowling, and we can write instruction books to build computers and spaceships. In many ways, language is the very thing that makes us human – or at least, that makes us a very special kind of animal. But our communication and that of other animals has almost as much in common as it is different. When we watch monkeys chattering to each other, or birds singing a duet, we are observing a set of behaviours that the ancient ancestors of humans also possessed, before any language had even evolved. At some point in ancient history, maybe a few hundred thousand years ago, our ancestors were not qualitatively different from any other species. Those ancestors gradually adapted the speaking abilities they inherited from earlier ancestors, right the way back to our common ancestor with chimpanzees, six million years ago. These were fundamentally the same communication tools as were used by the mammoths and sabre-toothed tigers who lived at the same time. Warning sounds and mating calls are common across all animals and, pushed by the spiralling complexity of our social groups, our ancestors built upon those tools until they evolved into the first language. No wonder, then, that our modern language retains many of the features and characteristics that we still see in the elephants and lions of today.fn2 Maybe that is why we are so fascinated with what animals are saying: they seem to be saying something fundamentally related to what we say, even if we are not always aware of it. The question of how much our language has in common with other animals, then, is one that speaks to our own identity as humans, and to our place in the natural world. As you read this book, I hope you will see trends emerging, common threads that come back again and again when we ask why a dolphin or a chimpanzee has such complex communication. And these trends apply no less to us humans and our ancestors. Our language might be fundamentally different from any other animal, but its roots are in the same constraints: complex societies, where individuals have complex things to tell each other.

Many books have been written on what animals are saying, sometimes how to talk to your dog, or how to calm your horse, and sometimes from a more scientific perspective. Often, books will present an argument from a position of assuming that animals have a particular ability – either that they are rational creatures capable of using language just as we are, or that they are mindless robots chattering instinctively. Neither of those positions is particularly generalizable or accurate. Both are mistaken for a very simple reason: all animals are different. Animals evolved to fill particular niches to achieve their goals one way or another: using fangs to catch their prey, or fur to keep warm in the snow, or sounds to convey information. Some animals need to say more, some animals need to say less. It would be a mistake to think that all animals have the same communication needs, and therefore the same communication abilities. Animals such as snails and worms may not have very much that they say to each other, simply because their lives do not require much communication to get on. In contrast, species such as dolphins and chimpanzees possess impressive abilities to communicate with each other, and even with humans. That’s a phenomenon that can only be explained in the context of the interactions between the animals and their environments, and particularly between the animals and other members of their species. Why animals need to talk is the important question to ask before we can answer how and what animals are saying.

The select few

Each chapter of this book focuses on an iconic or particularly relevant animal in our story. Rather than focusing on the science, I am going to focus on the animals, with some science along the way. It’s more fun like that. I’m going to try to take you into their world, because only from within their world is it possible to understand who these animals are. It’s not enough to rely on our deeply ingrained stereotypes of some of the most intelligent and vocal animals in the world: the vicious, evil wolf; the smiling, friendly dolphin; the mindless, mimicking parrot. Only up close and only in the wild can we begin to see what is happening in the minds of these animals.

My first chapter, Wolf, talks about the species I’ve probably worked with the most. Wolves are a key element in our quest because they share so much with us. They are intelligent and vocal, but most importantly, they are deeply social animals, and they cooperate so that their sociality gives them a survival edge.

In Chapter 2, we meet dolphins. These are, perhaps more than any other, the animal considered by many people to be hiding an intelligence that challenges our own. Everyone loves dolphins, but there are a lot of misconceptions about them, and some overenthusiastic comparisons with humans. Behind all the mystery and hype, though, lies a truly exceptional animal. Intelligent, yes; social, yes; communicative, very. What messages could they possibly be passing to each other – and why?

In Chapter 3, in come the parrots. Parrots constantly surprise us with their talking abilities. They seem to throw our words right back at us. Are they really saying anything? Are they really thinking anything? Can we even put ourselves into a bird’s brain? What is it about the life history of wild parrots that could possibly have brought about such unexpected abilities?

Next is a species unfamiliar to most: the hyrax. Small and furry like a rabbit, hyraxes are unusual creatures, but their long and complex songs uncover an important feature of animal communication: what is the role of complexity, and are animal songs just random, or do they have some important structure?

In Chapter 5, gibbons swing by. Gibbons are apes, like humans, but unlike the rest of the apes (chimps, gorillas, orang-utans, etc.), gibbons have an exceptionally complex and diverse vocal repertoire. Perhaps these long-armed relatives of ours, swinging gracefully through the jungle trees, have the closest thing to human language among our near relatives. Charles Darwin certainly thought so. If gibbons reflect the environment our non-human ancestors might have lived in fifteen million years ago, we can look at them and see a hazy image of how and why our forebears first began to use complex vocal communication.

But it is with chimpanzees – whom we will meet in Chapter 6 – that we are led most closely to understand ourselves as human beings. Seeing chimps in a zoo raises uncanny feelings of similarity: we are looking at an offshoot from our own roots. These animals express to each other more ideas – and more human-like ideas – than any other species. Not just who they are and what they want, but also emotions like friendship, concern, and displeasure. Even without a language, chimpanzees come close to living in a fully functioning and easily recognizable society. Surely they are the end-point of our search for what we have in common with the communication of other species?

Finally, where do humans fit into this menagerie? Humans aren’t somehow more evolved than any other species – every creature alive today can trace its ancestry back through exactly the same billions of years of evolution as us. We don’t do a better job of surviving in the world (indeed, the way things are going at the moment, we may be heading for our own self-induced mass extinction event), but we do have a set of skills that no other animal has. We have language. How much of what we say and how we speak can we explain through the hyraxes and parrots and gibbons of this book? Humans have poetry and music and technology and books. But everything that we have – even those things that other species have not – arose from our ancestors through natural selection. We owe even our unique language ability to the complex communication that we see everywhere in the natural world.

Sounds, not sights or smells

You might be surprised that I seem to focus only on vocal communication. Animals communicate in many different ways: through sight, like the coloured plumage of birds; smell, from the pheromones that attract a male moth to a female in the most minute quantity, to the cat whose urine scent-marking is detectable to any human visitor to your garden; tiny vibrations in the soil that are well suited to underground societies of mole rats; dances and postures, like the bee’s waggle dance that points the way to the best flowers; even electric fields, which some fishes, living in murky jungle rivers, use to communicate with each other their sex, dominance, and even individual identity. Each of these topics is worth a book in itself, and it wouldn’t be possible to do justice to the range of ways that animals communicate, any more than it would be to write a comprehensive book about all the things that animals eat. In some cases, for instance with chimpanzees, visual communication seems to be even more important than their vocalizations, and yet this book focuses almost exclusively on sound, for a couple of reasons. For one thing, sound holds a special place of importance. Of all the different media through which animals can communicate, only sound has these four crucial properties: it can travel long distances, it travels those distances fast, it can contain a lot of information, and, crucially, sound travels around things. Even if you’re hiding behind a tree, you can still hear the roar of the tiger who might want to eat you. For these reasons – and probably others too – sound has become the most important medium for communication on Earth. But my focus on vocal communication isn’t really just because of the unbelievable diversity of animal sounds that we find around us: from birds tweeting, to cicadas chirping, to whales singing. Awe inspiring as the sounds of nature are, the other reason that sound is so important to our story is that the only true language we know of – our language – is primarily a vocal one, even if supplemented by subtleties of posture: the ironic raised eyebrow, the puzzled tilt of the head, or the pitiful wide eyes. Some of the questions I’m hoping that you the reader will raise in your own mind are: Just how different from or similar to our own sounds are those sounds of nature? Is the difference between our language, and the communication of other animals, a difference in kind, or in degree?

Picturing sounds in your head

You don’t need to know much about animals to read this book. Most of us have already had some experience trying to understand what our pets say, or watching birds at the garden feeder, or even just revelling in nature documentaries. One thing you’ll need is an open mind about just how much animals are saying to each other. It’s unhelpful to start with a conviction that animals ‘must’ have a language like ours, or that animals ‘obviously’ don’t say anything meaningful. Let’s see what we find, and what the evidence indicates.

It would be nice if, reading this book, you could actually hear what kinds of animal sounds I am describing. Fortunately, in a way, that’s almost possible. There is a technique that scientists use to study the sounds that animals make, called a spectrogram. Spectrograms are visual representations of sound, and they make it much easier to understand the different elements, divide the sound up both in time and in pitch, and to imagine what it sounds like – just from a picture, without actually hearing the noises. Humans are excellent visual classifiers; in fact, we’re much better at understanding pictures than sounds, so it makes sense to convert complex sounds into a visual representation. With a bit of practice, it’s quite possible to imagine the sounds themselves, just by looking at the spectrograms. I will be using spectrograms throughout this book to illustrate the kinds of sounds that animals make, and the way that those sounds are arranged in time. But rather than presenting actual research spectrograms, as I would in an academic journal, here I’ll show simple representations of the spectrograms, reducing their complexity to highlight the most important features.

Understanding spectrograms is easy – they are conceptually very similar to printed sheet music. Time runs from left to right, and pitch from bottom (low pitch) to top (high pitch). Take the famous opening bars of Gershwin’s ‘Rhapsody in Blue’. The corresponding spectrogram may or may not look all that similar to you. But if I ‘cartoonize’ the spectrogram to pull out the important features, it looks a bit more understandable.

The flow of the music now becomes clear; with the signature clarinet glissando followed by what – even on the spectrogram – appear as separate and distinct notes. There’s no better way to visualize both music and animal sounds on the page of a book, and I will make liberal use of cartoon spectrograms throughout the chapters.

Just to make sure you’ve got this I have a little test for you. Can you recognize the spectrogram at the foot of page 20 without reading the caption? Here’s a clue: it’s the chorus of a classic 1968 song that featured in the movie Easy Rider.

2. ‘Rhapsody in Blue’ in musical notation …

3. … as a pure spectrogram …

4. … and as a cartoonized spectrogram.

5. The chorus of ‘Born to be Wild’ as a spectrogram.

Yes, it’s no coincidence that I choose to illustrate spectrograms with Steppenwolf’s ‘Born to be Wild’ – the howl-like chorus lends itself well to the kind of representation that we will use to illustrate not just wolf howls, but dolphin and parrot whistles, as well as hyrax wails and gibbon songs.

Between humans and animals

By this point, you will have noted that there are threads common to all these diverse species. Whether it’s family messages between wolves, neighbourly disputes among parrots, complex hyrax song or the long-term relationships between dolphins, and whether they live underwater, on the ground or in the sky, animals have similar needs: to carve out their place in their group and reap the support of that group. All have developed ways of talking about those needs. Without communication, sociality grinds to a halt. Without sociality, there would be no wolf packs, no chimpanzee troops, and, of course, no human cities.

And what, indeed, about us humans? How much are we qualitatively different from all these other animals, and how much do we retain of our ancestral need to communicate? Our societies are more complex, it is true, and our language vastly more so. Humans are special in a very simple way: because we are not limited in the number of concepts we can convey. It should be clear that this is absolutely bizarre, given that we have finite (and really rather small) brains. Nevertheless, it works. This book is utterly different from every other one of the 130 million or so books that have ever been published.fn3 No animal comes close. Even if some species, maybe dolphins, parrots, or chimpanzees, have the neurological potential to construct innumerable different messages, in the wild, for whatever reason, they don’t do it. Without the slightest attempt to rope off humans as being God’s pinnacle of creation, we can say that unlimited (or at least very, very large) communicative potential is what language is. And yet, this is a rather unsatisfying definition too. How did we get that unlimited ability – where did it come from? What pieces of a puzzle needed to be fitted together to make humans so special? And how many of those pieces do different animals have – possibly having them without using them to their full potential? Spotting those underlying commonalities can help us to communicate with other species as well. This is really where my book is leading. We humans have evolved our unique ability by building on foundations that are all shared with other species. Some have more, some have less. Even those with all, or almost all of the foundations haven’t combined them in the way that our ancestors did, when they began to speak ‘human’. Animals talk ‘animal’. It’s not a language, but it’s still fascinating to understand, and it underlies the basis of who we really are.

In the end, I want everyone to see the common threads linking us to our fellow animal species. True, few readers will ever encounter dolphins or gibbons in the wild. But when you make eye contact with a blue tit at your feeder, or with a fox crossing the street at night, understanding what may be going through the minds of these creatures will help everyone to understand the world around us. I’m not dismissing the question ‘Can we talk to animals?’ Rather, I want to see it in a way that can actually be answered, not avoided or fantasized. We scream when we are scared, and so do deer, so why shouldn’t there be much in common between us? But at the same time, we have evolved to do a particular thing: to speak to each other. Can we speak to animals too? Let’s have a look.

6.

1. Wolf

It’s very cold. Even among the dense trees where there’s no wind, the air stings. At first, the silence feels so intense you could be the only creature in the world, never mind in the forest – except that little rustlings of rodents in the snow remind you that there is life all around, albeit indifferent to your presence. Maybe there are other creatures out there too. Larger creatures. Soon, a low-pitched howling like the wind begins, rising slowly and mournfully before the pitch falls again. Another animal joins in. It’s an unmistakable sound and it sends a shiver through anyone hearing it. They’re calling across what seems to the casual observer an empty world, but this is their home. There is nothing that reminds us of the wilderness quite like hearing the wolves calling. What are they saying? Are they as lonely as they sound? As threatening? I want to understand these creatures, who they are, what they are saying, why they do what they do. They are so different from us yet so similar. Of all the wild animals, these are the ones with which we have the closest bond. Why? Because we’ve taken their relatives into our homes as four-legged companions and moulded them to our way of life, something that would not have been possible if we did not share so much to begin with. To understand wolves is to understand ourselves. So, where do we begin?

Humans respond viscerally to wolf howls. More than any other animal communication, this sound evokes feelings of a spiritual connection with nature. And feelings of danger. Personally, I find wolf howls beautifully calming. Here is a creature perfectly at home in a harsh environment. They need no warm house or advanced technology to survive. They can wander the forests just as we would wander our local neighbourhood, without worrying about being too far from home. What features of body and mind do wolves need to survive where they do? A human in the same woods would find them terrifying, as a wolf would no doubt be terrified and lost in suburban London. The forest is a desolate place, but when you are surrounded by family, it is familiar and comforting. Bit by bit, animals evolve to take advantage of resources that others shun, from the frozen wastes to the deepest ocean. There’s food in these forests, but to catch it, to survive, you must work as a team, rely on your friends and family, otherwise all is lost. Wolves do not howl to each other simply to threaten or to intimidate, but to communicate as casually as we might text a friend to find out how they’re doing, where they’re going. Shall we catch a bite to eat, or just hang out? This is an animal that wanders seemingly without concern tens of kilometres over mountains and through forests in a single day, and yet never loses touch with friends and relatives, as long as they can howl. The howl defines the wolf as much as its fangs or fur. It is an essential tooth in the cog of their existence, meshing perfectly with the cog of their environment. You can’t survive in the snow without fur. You can’t survive in the forest without howling.

Wolves are our introduction to the world of animal communication. They are familiar enough to strike a chord but alien enough to show just how different from us animals are. They have that key characteristic for complex communication to evolve: they are highly social. Living in a group is the only way for them to survive in their environment, but group living has drawbacks too. They must negotiate the social environment, as well as the physical one, and they do that using complex communication. Do all wolf howls sound the same to you? They vary almost infinitely and carry that variation reliably over many kilometres. We can look at their howls and investigate how much meaning they contain, and how they evolved to be complex enough to contain any meaning at all. If we can do all that, can we tap into this? Can we interpret the communication that is their private domain, and then reply in kind?

Who are the wolves?

Wolves are one of the most difficult animals to study in the wild. You might have thought that the frontiers of scientific knowledge lie in the most distant galaxies, or in the heart of the atom, or at the depths of the ocean. On the contrary. We know comparatively little about the behaviour of one of the most familiar animals on the planet. Wolves are exceptionally cautious creatures and avoid humans far more than the horror movies would have us believe. I’m often asked, ‘Aren’t you scared that the wolves might attack you when you’re out in the wilderness?’ Well, no; no more than I fear skidding off an icy mountain road (actually, I am considerably less scared of the wolves than of the roads). Despite their sharp fangs and claws, and their ability to bring down elk, and even massive bison, wolves are wary. That is not surprising. Like most top predators, they live on a knife edge between survival and starvation. Their lives hinge on the success or failure of a hunt, and a hunt can, and often does, end in near-fatal injuries for the predator as well as for the prey. In a fight for its life, a bison can use kicking hooves and sharp horns with lethal effect. For a wolf, caution is paramount. Humans are unfamiliar, unpredictable, and best avoided. Given that wolves can travel with breathtaking efficiency over rugged landscapes and deep snow, it’s no wonder that, if they don’t want to be near you, you won’t get anywhere near them. Add to that the fact that much of their activity is at night or at dusk, and you can see that there must be much we still don’t know about their lives.

Wolves have a special place in the hearts of many. We have all seen them on TV documentaries or in zoos, and some of you may have caught glimpses of them in the wild or heard snatches of their haunting howls. But even zoologists like me don’t have a very clear window into the life of a wolf. Perhaps the most reliable and detailed insight into what it means to be a wolf comes from the long-term scientific studies of the wild populations in Yellowstone National Park in the USA. Here, scientists and volunteers follow wolves daily, observe them, get to know the individuals, and track their comings and goings, the ups and downs of their packs, over years and decades. Ernest Thompson Seton, the great naturalist and animal writer of the end of the nineteenth century said:

How many of us have ever got to know a wild animal? I do not mean merely to meet with one once or twice, or to have one in a cage, but to really know it for a long time while it is wild, and to get an insight into its life and history. The trouble usually is to know one creature from his fellow. One fox or crow is so much like another that we cannot be sure that it really is the same next time we meet.1

There’s deep truth in this. If you think about the songbirds or the squirrels in your garden, do you really know one from the other? Without recognizing individuals, the most we can know is an averaged, smeared-out knowledge of all members of a species put together. Spotting individuals, separating them and their behaviour, and recognizing what they do as individuals is central to studying animal behaviour as a scientist. To understand animals is to understand the stories of animals as individuals, observed in the wild, but recognized as separate from their brothers and sisters, and from strangers of the same species – who might look the same to us, but can be perceived as mortal enemies by the animals themselves.

The team that has studied the Yellowstone wolves since their reintroduction in 1995 spends long hours in freezing conditions, watching through spotting scopes as the animals do almost nothing. The wolves relax, play, or perhaps investigate some branch sticking out of the snow. Sometimes they hunt; sometimes they fight; sometimes they mate. But mostly they just hang out and be themselves. It’s through those interactions – when the animals aren’t doing anything special, just being themselves – that we can see the individual, and in that way see what it is to be an animal in the wild.2 It’s easy to slip into thinking of wolves as being just communal hunters. But they are actually communal players, communal sleepers, communal resters, and, of course, communal singers.

Like many social animal groups, wolf packs are mostly extended families, where children remain with their parents – sometimes for years or sometimes leaving sooner to seek their fortunes on their own. Family relationships are a powerful force driving cooperative behaviour. The animals have evolved to support and help their kin, as this is in their own interests, making sure that their genes are represented in future generations through their nieces and nephews, as well as through their own children. Family social groups are extraordinarily common across the animal kingdom, from meerkats to beetles. And, of course, humans. We want our children to learn, to enjoy their childhood, and to grow to be healthy and successful. Not to mention to support us in our old age – even this occurs sometimes in other animals, and in wolves especially, where older or infirm animals take over caring for the pups while the others are hunting, and are brought a share of the kill as well. Wolves are special because wolves can only survive in groups, and the larger the group the better.

7. Observing wolves in Yellowstone National Park. My colleagues and I spent long hours standing in the snow and catching sight of the animals only from a distance and through a telescope.

When you feed on prey much larger than yourself (elk, bison), you can’t hunt alone, and the classic niche of the wolf is in the long chase, multiple hunters wearing down the unfortunate caribou until it is possible to disable the animal, or simply bring it down by sheer weight of numbers. However, it turns out that, for wolves, large hunting parties don’t greatly increase the chance of a successful hunt. A group of four seems to be about right for catching most prey, although it may be that in extra-long chases against animals of exceptional stamina, having substitutes to provide fresh legs halfway through the pursuit could be of some help. Yet wolves often hunt in packs much larger than four. That’s because packs aren’t just for hunting. A wolf pack is a complex social entity, providing benefits right across the board, without which life would be much harder for everyone.

For one thing, once you’ve got that caribou, the rest of the scavenger world descends on the carcass hoping to snatch a share. Coyotes, ravens, even bears. That large pack might not be necessary to bring down the prey, but it’s essential in keeping the outsiders at bay. And, of course, other wolf packs are also out there competing for your territory and your kills. When you are in constant conflict with neighbouring packs, there is strength in numbers. It’s both the size of a wolf pack and the age and experience of its members that determine the pack’s strength, and the chances of individual wolves surviving and reproducing. This is particularly true during encounters between packs, where the likely outcome (victory or defeat, or perhaps détente) is carefully assessed by the rival groups before entering a potentially costly conflict. Finally, as wolf packs are a kind of extended family, aunts and uncles have a role in helping to protect, and provide food for, their nieces and nephews. If you’re seeing parallels with human social organization, you’re not wrong.3

For all the patent benefits of gathering in a large group, it’s clear that there will also be squabbles, competition, and conflicts of interest. The more animals that live together – in particular, the more unrelated animals that live together – the more potential for conflict within the group itself. What to do? Wolves cannot survive in small groups but cannot survive in large congregations either. Just as in human societies, wolves must negotiate social relationships, sometimes plead, sometimes cajole, and sometimes threaten. Cooperation requires effective communication – both of the details of the cooperative task at hand and, importantly, of the fact that this cooperation will be a friendly activity, not an aggressive one. We are instinctively attuned to this, because humans have the same need to make clear to others not only that we want to help each other but also how we want to help. On the other hand, no less important is effective communication of unfriendly intent – it’s much better (for both parties) for a conflict to be resolved by mutual agreement than by violence. A little bit of fist shaking is better than an all-out brawl. You could say that ‘gunboat diplomacy’ has its benefits: the larger and more powerful wolf pack makes the less powerful pack think twice about starting a conflict. Effective social communication helps keep a pack cooperating peacefully, but also gives an animal an advantage when interacting with stranger animals. Adolescent wolves leaving home to make their fortune need to find a mate, perhaps to join another small pack if there’s no other choice available. The more socially adept loner is going to be the more successful loner. Communication is the glue that holds this complex society together, and this is no less true for the wolves of the Rocky Mountains than it is for the humans of New York. The more complicated and fraught an animal society is, the more it relies on complex communication to keep the paws padding smoothly.

As we dive into the communication of wolves – and so into their social environment, and so into our own human social environment – we have to ask questions to which the answers aren’t yet clear. To understand why wolves howl the way they do, we first need to understand why wolves howl at all. And for that we need to understand what a howl is.

Communication in the pack

Like any animal, and particularly any social animal, wolves communicate using a diverse range of tactics: messages sent by sound, sight, and smell, with subtle variations in meaning (perhaps imperceptible to humans), but overall aimed at improving an animal’s fitness to survive and reproduce. What we loosely call ‘body language’ overlaps constantly with more overt forms of communication. Pups signal their need (or desire) to be fed, with begging postures and cute but slightly pathetic whining. Adults signal their desire to mate – or not to mate – largely by posture, but a female will not hesitate to repel a male with an angry growl if she’s not in the mood. A wolf pack is a busy, complex unit of many interacting animals, all jockeying to be understood. When close to each other, wolves use a wide range of sounds: noisy growls and barks that make them sound more like dogs, as well as shorter, softer modifications of their iconic howls: ‘whines’, ‘whimpers’, and ‘yelps’ being some of the terms that scientists use to describe such a wide range of sounds. At close quarters, it’s easy to pick up on the subtle differences between these different sounds, and that’s why they’re useful – as any dog-owner can testify, an angry growl sounds decidedly different from a growl while playing tug over a stick.

Often, we humans can instinctively understand some of the meanings of these sounds. Growls actually sound angry, whines sound pleading. Is that just our overactive human imagination? Not really. For one thing, it makes sense that natural selection will have caused our ancestors to realize that a growling wolf is angry: that’s a big survival advantage when facing a predator in a bad mood. For another thing, there are common acoustic characteristics of particular meanings that are easily understood even by different species. There are some sounds that are technically called ‘noisy’ – not because they’re loud, but because they are made up mostly of noise (as in white noise), rather than having any pure tones in them. You can tell a ‘noisy’ sound from a ‘tonal’ sound pretty easily: growls and barks are noisy, whereas howls are tonal. Noisy sounds are generally interpreted by animals of a wide range of species (not just wolves and humans, but deer and sheep too) to be sounds of aggression and fear. Tonal sounds, like whines, are interpreted as being friendlier. That might sound surprising, but it has an evolutionary basis. When you’re practising for a singing recital, you need to control the sounds you make very carefully. On the other hand, when you’re watching a movie and a clown unexpectedly grabs a child to pull him down a drain, you scream. That sudden expulsion of air is involuntary, it’s uncontrolled, and it’s that lack of control that makes a ‘noisy’ sound, as opposed to a tonal singing voice. Noise is a natural reaction to fear, in humans, wolves, and sheep.

But our close affinity with our own domestic dogs gives us an even deeper level of understanding of wolf communication. Many years ago, at a wolf rescue sanctuary, Wolf Mountain, in Lucerne, California (well worth a visit), I stood not one metre away from a giant tundra wolf named Istas Pejuta (‘Medicine Eyes’, in the Native American Lakota language). As he appraised me for several long moments, I could see the change in his body language, from uncertainty to relaxation and finally acceptance, as he stretched out his muzzle to mine. We touched noses. Quite extraordinary. Here was a striking example of social communication between species. Should Istas approach me? Flee? Perhaps even attack? This was the importance of the messages silently exchanged between us. Even I, as a human, knew not to push upon him a social interaction before he was ready. We really do pick up on these kinds of cues very easily when observing both dogs and (if we are lucky) wolves. For members of the same pack, it is vitally important to pay the closest attention to every communicative cue and to understand what the intentions of your social partner are.

What is a howl?

Complex and important as these short-range signals are, howls seem to be something different. For one thing, they’re loud, clearly intended to be heard at a distance. That’s already important, because the howler, and the wolf hearing the howl, might not be able to see each other. This howling interaction is very different from the growls and whines that are part of a conversation between two individuals. Howls are mostly not directed at a particular animal. When you see wolves howling in the zoo, they go through a striking transformation, and it’s a sharp contrast to their normal interactions. One stops paying attention to the others, throws back their head, and howls to ‘out there’. A second animal, seeing that their pack mate has stopped interacting with them and has started howling, also stops what they are doing and begins howling too. Howls also have the distinctive property that they are simple sounds: they are tonal, containing one voice, a single note, even if that note varies up and down in pitch. And this is the key to wolf howls. That wolves put all their energy into a single note tells us that they have evolved this kind of call for long-range communication. Like a laser beam, focused into a pencil-thin ray of light, a howl focuses its energy into one frequency, and that energy can still be heard many kilometres away. Howls, unlike the moans, barks, and growls of their short-range calls, are adapted to travel, and to remain both detectable and distinct, over long distances.

Human speech is more like the short-range calls of wolves. The words we use are rather noisy, not pure tones like a flute, or even a combination of pure tones like a piano. Although we do make tones when we speak (these are mostly vowels, like ‘eeee’), we combine them with hisses, buzzes, clicks, and other sounds made by our complex system of tongue, nose, and lips. Our words are hugely diverse and varied, but the variation is subtle. We can make a lot of different sounds, and we can also easily recognize each other as individuals from the sounds of our voices. But the way you can tell the difference between your mother and your boss is precisely using those subtle differences, and at a distance, those cues – cues both to word meaning and to individual identity – are largely lost. You might be able to hear your friends shouting at you from across the valley, but you would neither understand what they are saying, nor even recognize who they are. In contrast, if you use a tonal sound – yodelling across the valley, say – your message is easily recognized. The simplicity and concentrated energy of the pure yodel tones mean that they are reliably transmitted across great distances. You can’t really distinguish one yodeller from another, but that doesn’t matter: it’s the up-down of the pitch that is important. This is precisely what wolves do when they howl. Discarding the rich information available in their whining growls, they howl with a clear message that, while nuanced, can contain only limited information: perhaps ‘I am here’, or ‘help me’. Howls can be heard at a range of ten kilometres or more – a huge distance for the sound of a single animal. Growls and whines can’t be heard more than a few tens of metres away. There is a trade-off between information content (how much you can say), and long-range fidelity (how reliably that message gets across), and wolves prefer their howls to be heard, even if they can’t say quite as much with them.

Even though howls contain less information than short-range communication, there is still scope for different messages to be transmitted over these long distances, just as there is with different yodel patterns. A pure tone can be varied, higher or lower in pitch, and this variation in pitch carries meaning. We are well used to musical motifs that contain information: descending pitch for drama (like in the opening of Beethoven’s Fifth Symphony), or a cheery, rising pitch (the overture of Mozart’s The Magic Flute, for instance). Similarly, wolf howls can vary in pitch, and that variation is reliably transmitted over long distances, just like the howl itself.

Every child practises howling like a wolf at some point in their youthful games. Typically, imitation howls – even if you ask an adult to produce one – go something like this: a short, low pitch, suddenly rising to a high pitch, and then slowly declining in pitch somewhat, as shown in the spectrogram. Try it yourself.

If you want to improve the realism of your own wolf howls, notice that humans usually exaggerate the sudden rise in pitch. Try a more subtle ‘a-woo-ooo’: it’ll sound much more realistic. Even though wolves don’t really howl quite like children do, it doesn’t matter all that much. The important point is that what strikes us about the howl is the general pattern: a rise in pitch, and the subsequent gradual fall. That is characteristic of wolf howls, so even if the details of an eight-year-old’s howls wouldn’t convince any real canid, and even if it lacks fidelity to the detail, we’ve picked up on the essence of the sound. Howls, just like flute concertos, are defined primarily by the changes in pitch (together with the timings of those changes). Changes in pitch and tempo are easily detected at long distances, whereas every other aspect of the sound is attenuated and lost.

8. A spectrogram comparison of wolf howls (1).

Changes in pitch (frequency modulation, or FM) is the method of choice for many different kinds of long-range communication. Variation in volume (amplitude modulation, or AM) is too unreliable – wind, rain, even trees in the path of the sound, can alter the volume pattern and scramble any AM information. So, it’s not surprising that howls go up and down – it’s the only way to transfer information reliably over such distances. As you’d expect, those minority of howls that are specifically intended for shorter ranges don’t have that constraint. For instance, when two wolves are facing off against each other, the howls they make are ‘noisier’ – they contain more AM. If you walk round a tree and find yourself face to face with a strange wolf, it’s best to be sure that your signals are clear and understood – and that you clearly understand your opponent’s signals. That AM information won’t be lost by the time it reaches your opponent on the other side of the clearing, as it inevitably would be lost at a range of five kilometres. It has also been suggested – at the level of informed speculation – that when howling at short range, changes in volume could be used to change the meaning, or perhaps the emphasis of a howl. Just like placing stress on one word or another can change the meaning of a sentence (as I just illustrated with the italics in the previous sentence). Perhaps emphasis on the rising part of the howl (Magic Flute) could be interpreted differently from an emphasis on the falling part of the howl (Beethoven’s Fifth). At least, it seems reasonable that such an opportunity to add emphasis might be exploited.

We can take advantage of the fact that the essence of the howl is the pattern of changes in pitch. I may not be able to howl much like a wolf, but from a couple of kilometres away, the wolves won’t be able to tell the difference anyway. All they hear is the up-down of pitch, and if it follows the pattern of a wolf howl, it might be a wolf. And they respond. This makes the howling survey a popular way for scientists to assess pack numbers and locations. In a remote corner of Wisconsin, I stood in the dark and silence, with my luminous compass in hand, waiting for the noises of our rapidly cooling car engine to die down. After a few minutes, my colleague Angela Dassow began to howl the loudest and best imitation of a wolf that she could. A few seconds later came the reply. Quickly I took a bearing with the compass to estimate the pack’s location. Surveys like these are used all over the world to assess wolf populations. It seems that, just as in the movie Who Framed Roger Rabbit, where cartoon characters can’t help completing the comic riff (‘no toon can resist the old “Shave and a Haircut” trick!’), so wolves just can’t help responding to humans pretending to howl. Afterwards, we examined the howls on our automatic recording devices that were placed nearby (see spectrogram). It’s almost impossible to tell Angela’s howl from a real wolf, except for the regularity of the timing with which she howled. Humans are, it seems, a little more predictable than other animals.

Wolves have many close relatives in the wild who also howl, but don’t necessarily have quite the same need for long-distance communication. Coyotes, for example, live in smaller family groups than wolves, hunt smaller prey, and consequently range shorter distances to find that prey. They don’t need their calls to carry ten kilometres. Coyotes, and their old-world equivalent, the golden jackal, still howl, but their sounds are dramatically different from those of wolves. Although the basic howl of a coyote is essentially similar to a wolf howl (despite being generally higher pitched), coyotes often follow a lead howl with the most ridiculous cacophony of yips, squeals, overlapping howls and barks. Once coyotes get started, the tranquillity of the forest is shattered by a wall of sound so confused and complex that it is impossible to disentangle who is making what sound. Coyotes quite deserve their nickname of ‘song dogs’. Established opinion (although not really based on any empirical investigation) is that such a chaotic chorus is adapted to confuse enemies, and to hide the number of animals present, making it sound as if the pack (typically comprising only three or four) really consists of ten or twenty snarling, aggressive animals. This idea was dubbed the ‘Beau Geste’ effect, after the hero of a 1920s colonial adventure novel, in which the protagonist lined the battlements of a fort with the bodies of dead soldiers to make it appear that the number of defenders was greater than it actually was. Like most untested theories for animal behaviour, this may be a fanciful explanation – until we test these ideas, they remain no more than notional. However, it’s certainly true that it is almost impossible to determine the number of coyotes howling once they get into one of their messy choruses.

9. A spectrogram comparison of wolf howls (2).

Red wolves, common across the eastern United States until the arrival of Europeans, but almost extinct in the wild now, are much smaller than grey wolves, but larger than coyotes, occupying a niche between the two. They howl more like grey wolves, without the cacophony of coyotes, but their howls are still more modulated, more variable than their larger cousins. Whether this is because of their greater genetic similarity to coyotes, or because of the greater similarity of the niche they occupy, we don’t know.

One of the ways of testing a hypothesis such as ‘Wolves howl the way they do because it’s effective for long-range communication’ is to examine what evolves in other, unrelated niches with similar constraints. Incredibly, those two characteristics – a pure tone, and the slow variation in pitch – are mirrored in just about the most distantly related mammal species that you can imagine: a dolphin. The whistles of dolphins show almost identical properties to wolf howls. True, dolphin whistles are about twenty times higher in pitch – so high pitched that it’s sometimes difficult for humans to hear them. The whistles are also about twenty times shorter than wolf howls. But if you slow that dolphin whistle down sufficiently, it does sound remarkably like a wolf howl. Dolphins live in an underwater environment where visibility is limited to just a few metres, and an animal a hundred metres away might as well be three kilometres away. A pure tone, modulated up and down in pitch, seems to be the most reliable way to transfer information in this environment as well as in the snowy forest habitat of the wolf. We’ll talk about this remarkable similarity in the next chapter.

Howls and their meaning(s)

What might wolf howls actually mean? That is a very difficult question to answer, because it’s not at all clear that the concept of ‘meaning’, as we understand it, is directly applicable to animal communication. We are comfortable with the idea that a certain word has a certain meaning, and for the most part, that meaning doesn’t change with the context. We need to be a little bit more careful when applying this concept to animals. That’s not to say that animal signals don’t contain clear meanings. Experienced wolf watchers have documented plenty of cases where one animal calls to another, and the call is met with an immediate, appropriate response. Communication doesn’t exist if it doesn’t cause changes in an animal’s behaviour. Rick McIntyre’s book The Reign of Wolf 21 describes a case where a group of wolves is suddenly attacked by rivals. The pack’s dominant female steps away from the fight to howl, bringing immediate reinforcements from the remainder of the pack, kilometres away.4 There can be little doubt that the wolves understood the message in the howl, and the call elicited the required response, so the communication worked. But that’s not the same as saying that this particular howl meant ‘Help us!’ We have to be a little careful about assuming that a wolf howl – or any kind of animal communication – has such a specific meaning, or whether we can explain the behaviour with more general statements about more general messages. Even so, it’s generally accepted that wolf howls do, in fact, have at least three different meanings – or perhaps more accurately, howls fulfil at least three different roles: marking out their territory, keeping in touch with other members of their pack, and simply satisfying the animals’ love of howling.

Firstly, wolves howl to advertise their territory. That is, they want to send a message to other wolf packs to stay away; that this area is already home to some wolves, who will jealously guard their resources and won’t take kindly to other hunters chasing their meals. Lions and tigers roar to advertise their territory too – it’s a common behaviour that we understand instinctively. And, of course, it makes sense that if your territory covers hundreds of square kilometres, and you’re signalling to warn off competitors, your calls have to be able to travel a very long way. Birds also advertise their territories, but as their territories are often measured in tens of square metres, not hundreds of square kilometres, their calls are quieter and less penetrating.

Precisely how, when, and where wolves howl to mark out their territory is yet another thing that isn’t well understood about these complex and cryptic animals. We know that conflict between different packs is a major cause of injury and death to wild wolves – at least, it is in that location where they have been best studied, in Yellowstone National Park (we mustn’t forget, though, that the wolf is the most widely distributed terrestrial predator in the world, and the territoriality of wolves in the Himalayas, in the Arabian Desert, and in the islands of the Arctic could be completely different). Wolf territories overlap, and those border areas are where the majority of conflicts – and the majority of wolf deaths – take place. It seems that deer and other prey animals survive better in those border areas too, which implies that the wolves themselves are wary, and avoid approaching a rival pack’s territory. It’s not surprising, then, that wolves don’t seem to go up to their borders to howl – and why should they? Far safer to remain in the centre of your territory and let the long range of your howls do the job for you. Yet another reason why howls must be effective at a range of many kilometres.

Secondly, wolves probably also howl to keep in contact with other members of their pack (as the story of Wolf 21 illustrates). Living in such a large territory, the individual animals often wander far and wide, and reuniting (to hunt, or to look after pups) is no easy matter. Sometimes individual wolves wander in search of prey, to patrol their territory, or just because they feel like a walk – we really have no objective way of figuring out what’s going on inside their heads. But if everyone ambles around independently, soon the whole pack will be dispersed, potentially tens of kilometres apart. Female wolves also often move their pups from den site to den site – under what stimulus, we don’t know. But imagine coming back from checking out the elk and finding that your mate and her young simply aren’t at home any more. Howling seems to be used regularly for individuals to find each other again, either spontaneously, so that periodic howling means that everyone always has some idea where everyone else is, or with purpose, if some members of the pack are missing. Again, this kind of call must be heard, and recognized, right across the pack’s home range.

But the third reason that wolves seem to howl is just because they like it. Adaptive explanations such as territorial advertisement or audibly tethering separated pack members lead to a situation where wolves howl often. It becomes a habit. And it also becomes part of their social structure. If howling represents threat (territorial incursion), or isolation (calling to separated pack members), then it is not surprising that wolves howl when they are together: to reassure themselves both that there is no territorial threat, and that no one is missing. This method of solving problems of survival has become a tool of social cohesion – a common occurrence that we see in human society as well. Singing and dancing in our human ancestors probably once served to tell stories, and teach hunting techniques, but have become repurposed for bonding a clan closer together (even if different generations traditionally disapprove of each other’s taste in music). In captive animals, it’s strikingly apparent that wolves actually want to howl. Whether they’re resting, feeding, or patrolling their enclosure, the others jump up and join in whenever one wolf starts howling. Some years ago I was observing three Arctic wolves, Masaak, Sikko, and Pukak, at the UK Wolf Conservation Trust in southern England. These three impressive, powerful, snow-white (but very muddy) animals were pacing around their large enclosure. The largest, Masaak, climbed a small mound and began a deep, sonorous howl. Pukak, the lowest ranking, immediately threw his head back and began to howl as well. Sikko, the only female, looked over her shoulder at Pukak with an unmistakable air of not wanting to miss out, and started howling too. By now, Masaak was out of breath, but started howling again. Their body language seems to support the idea that they are enthusiastic about this noisy social interaction. Domestic dogs do the same. You might choose to call this an instinctive response, but there seems to be little difference between that, and ‘wanting’ to howl. A chorus of howls is not just an aggressive or lonely sound, but a rather joyous one.

10. Sikko, an Arctic wolf, at the UK Wolf Conservation Trust.

Do these three roles of howling mean that wolf howls have three different meanings? One type of howl to say ‘stay away’, one type of howl to say ‘come here’, and one to say, ‘time for a sing-song’? It would seem to me that trying to impose a concept like ‘meaning’ – however obvious it may seem to us – onto animals that don’t have an actual language is an enterprise doomed to failure. We understand ‘meaning’ as having a clear definition at all only because we have language. Words have meaning. Sentences have meaning. But language is very exceptional. Our ability to convey so much information is deeply rooted in the idea of distinct meanings. If you don’t have a language – you don’t even have a concept of what a language might be – then you probably don’t have a clear concept of unique meaning. When we move away from linguistic messages, meaning becomes less obvious. Does a popular song have a single meaning? Probably not. A song may invoke particular emotions, maybe even have a fairly consistent emotional theme, but it would be a stretch to say that the literal meaning of ‘Eleanor Rigby’ is ‘loneliness’, for example. Similarly, howls seem to be able to convey ideas – perhaps even fairly complex ideas – without needing distinct, discrete meanings, in the sense that our language-infused brains expect. Our sense that a particular howl may sound ‘lonely’ is unlikely to mean that wolves necessarily interpret that same howl to be a lonely howl. Nonetheless, the fact that we ourselves can perceive general emotions in sounds without referring to a linguistic interpretation means that other animals may well be able to do the same. For animals that live in close proximity, and vocalize frequently, understanding each other’s emotions in their vocalizations does not sound unrealistic.

One thing that does seem to correlate quite clearly with different kinds of signals is emotion. Screams of fear in everything from rats and marmots, dogs and cats, deer and rabbits, share some acoustic properties; they are genuinely scary.5 If you’ve ever tried soothing a pet rabbit or a kitten, you’ll have noticed that ‘cooing’ sounds work on them, just as they work on a human child. We have a large vocabulary of words for different emotional states – but then, our brains probably can take more distinct states than those of other animals, and more importantly, we can talk about and describe them, so it’s no surprise we have so many words. It’s a bit harder to talk about distinct animal emotions, but it’s not impossible. Animal emotions seem to depend on at least two different factors: how scared they are, and how excited they are. This has led to a simple and popular way to classify emotions, commonly used in animal behaviour research, known as Russell’s circumplex model (see diagram). On the one hand (axis), an animal can be anywhere from feeling very positive about something (like it might feel about food), to being neutral (like to a rock), to feeling negative about it (like a predator). On the other hand (axis), an animal can be anywhere from being excited (either positively or negatively), to being utterly indifferent. The two axes are independent, so you can have any combination of the two factors: excitedly happy, to indifferently sad, and everything in between.

11. Russell’s circumplex model.

One reason this model is such a popular way to describe animal emotions is that it relies only on simple emotions that we’re pretty confident are shared by most animals of almost every level of complexity. But its other big advantage is that it encapsulates very well how animal (and probably human) emotion is really an endless continuum of different combinations. We have distinct words for distinct emotions (‘glee’ as opposed to ‘joviality’), but animals don’t. Everything is a continuum – and that soothes our concerns about inappropriately assigning hard-and-fast meanings to animal sounds. A ‘hello’ howl doesn’t necessarily mean ‘hello’ – it might just be more hello-like than another howl. A ‘stay away’ howl doesn’t literally mean ‘stay away’, but it can contain elements of negative excitement, which another wolf is going to interpret appropriately. In fact, MRI brain imaging has revealed that both dogs and humans respond in a similar way to these kinds of cues of emotion in the sounds they hear.6 This ability to interpret similar emotions via similar sounds would seem to be a very deep evolutionary connection between us and other animals.

It may or may not surprise you that very few animal studies have uncovered any sounds that have particular meanings – concrete and specific concepts – rather than just being expressions of particular emotional tendencies. Uncovering distinct meanings in wolf howls is something that my colleagues and I are working on right now, but it’s an unusual and uncommon research project. It’s a promising direction, since we’re fairly confident of at least three contexts in which the howls are used: territorial, keeping contact, and just for fun. But it’s challenging too, because most of the time we haven’t any idea what the wolves are actually doing when they’re howling. They’re too far away, hidden between trees, or it’s night-time and we can’t see them anyway. But by using some technological tricks, we can triangulate the geographical location of the howlers, and infer whether they are – for instance, together or far apart. Analysing howls from Yellowstone National Park gives some interesting results.

Different types of howls do seem to be used in different contexts, with flat, simple howls used in choruses, for example, and howls with more variable pitch used when an animal is separated from the others. But is this just a reflection of their emotional state – maybe lonely wolves just can’t control their pitch – or is it a message that the howling wolf intends to send, and something that the listening wolves actually understand? Would wolves in Wisconsin understand the howls of Yellowstone wolves, by which I mean, would they respond appropriately? Or are these differences in the way a howl sounds mere coincidences, with no relevance to the meaning of a signal? Understanding animal communication still has a remarkable way to go.

12. A spectrogram showing different types of wolf howl.

Wolf dialects

It is a frosty November morning in northern Italy, and five of us are sitting under a small oak, staring across a deep ravine waiting for the wolves to appear. Scanning the boulders and shrubs with binoculars, we finally see activity: some young wolf pups begin frolicking around, chasing each other and investigating their surroundings, while the adults catch some early morning sun as the mist clears. No more than 400 metres away lies the nearest farmhouse. Yet none of the neighbouring farmers are aware that wolves live so close to their homes – and would doubtless be maddened to discover that is the case. However, with flocks of sheep effectively defended from predators by the loyal and naturally suspicious Maremma sheepdogs, wolves content themselves with wild prey: deer and rabbits – far less impressive than the dramatic bison hunts of their American cousins. They don’t impact on the livelihood of the farmers, and so evade detection.

But at night, listening to the hum of traffic with my colleagues Martina Lazzaroni and Martina Russignan, a distant radio playing, and the occasional barking of farm dogs, another thing becomes apparent. Some sheepdogs start barking, then howling. The dogs from the neighbouring farm pick up the howl. And then, in response to the symphony of sheepdogs, another howl can be heard. Martina, Martina and I look at each other: clearly this new voice belongs to a wolf – but it sounds so similar to a dog! Anyone unfamiliar with wolf howls would not have been able to distinguish them. In the face of angry opposition from farmers to the presence of wild predators, the wolves had a great trick up their sleeves to help them eke out an existence right among their most mortal enemies. They howl like dogs. Listening to the recordings I made those nights, it’s not so easy to tell the wolves from the Maremmas.

Mostly, wolf howls are very characteristic, not only of wolves per se (as distinct from their close relatives, coyotes, jackals, and dogs), but also of the particular kind of wolf that is howling. European wolves have long, low-pitched howls that are monotonous and flat. American timber wolves often precede their flat howls with a rise and fall in pitch. Arctic wolves do the same but go higher in pitch when they go up. Some years ago, one of my colleagues, Holly Root-Gutteridge, told the story of her disappointment that a recent horror movie she had seen, set in Transylvania, featured wolf howls that were clearly from North American wolves. We were so taken with this idea that we gathered hundreds of wolf howls from across the world and found consistent patterns between different countries. This is how scientific research begins.

But these Italian wolves sounded more like dogs than the European wolves of Scandinavia or Russia. Dogs howl in the most peculiar way: varied and unpredictable. And the Italian wolves were following their lead. Was that because they knew they needed to disguise their presence from humans? Or was it simply that they were copying the howling they heard around them? North American wolves are quite a bit larger than Italian wolves – they weigh about 40kg compared to the 30kg of their European cousins. Naturally, therefore, they howl at a lower pitch, just as a tuba produces a completely different pitch from a piccolo. But what about the pattern of their pitch? Why do wolves in one country stick to a single note, whereas others rise and fall in pitch? There are three possible explanations.

13. A spectrogram comparison of wolf howls (3).

Firstly, it may be that the different populations of wolves really are genetically so different from each other that the howling parts of their brains are built differently – an Arctic wolf has a brain that makes it more likely to warble than a European wolf, and a more conservative, sedate howling instinct. But such genetic explanations of complex behaviour are worryingly tenuous. Unlike the evolution of physical structures in the body such as muscles and nerves, we don’t have any clear mechanism for explaining how instincts are inherited – although clearly, they must be, at least for basic functions, such as fear of predators, or attraction to potential mates.

Secondly, the wolves may be learning from their parents and pack mates how to howl. Just as human language dialects and accents arise from the gradual divergence of tradition in different populations, so wolf howls will gradually form into dialects. The mountain folk of Appalachia sound different from the Scottish farmers from whom they are descended. New quirks of speech arise randomly, and quickly become incorporated into the common way of talking. So too with wolves: distantly separated populations will eventually come to sound different, just because pups copy the adults.

It should not be difficult to investigate this question: American wolves are often raised in zoos next to European wolves – how will they howl when they grow up? If they howl in an American accent, then the diversity of howls is likely genetic. If they howl as a European, it is likely learned. Surprisingly, no one has done such an experiment so far.

But there is a third possible explanation. Different kinds of wolf howls may truly have different meanings. Different patterns of pitch, warbling up and down more or less, may be suited for a particular purpose. In the huge territories of the frozen north, reuniting pack members is such a vital role of howling that it is crucial to be able to identify individuals from their howls – so the howls are varied. In smaller European territories, and in the Mexican desert, it is enough to advertise the presence of your pack, so a flatter, simpler howl suffices. As with the possibility that different emotions (e.g. loneliness or contentedness) might affect how much variation there is in a howl, so the very role that the howl must play surely affects its structure. The red wolf, part way between a grey wolf and a coyote both in size and in niche, howls partly like a grey wolf and partly like a coyote – not because of some genetic mix-up between the two, but because their lifestyle, their need for communication with each other and with competitors, requires a mixture of both. I’d love to think that howling is both learned and adapted to the environment. It would be a fantastic way of understanding meaning in animal calls, not as a crude translation of how humans perceive meaning, but as a direct representation of what the animals themselves need. But of course, reality doesn’t pay much attention to what I’d love. One day we will uncover the truth, and it will be one way or the other. Or possibly yet another, which we haven’t even thought of yet.

Can we talk back to the wolves?

Like it or not (and I do not), our relationship with wolves is confrontational. Farmers are resentful when wolves eat some of their livestock, as the wolves must do to survive. It surprises me that people whose entire lives are based on a relationship with nature react so strongly to nature taking its course. But even those who have never seen a wolf, never even walked through a forest at night, still fear wolves. It is a fear deeply ingrained in our culture – outdated, and deeply harmful to a balanced natural ecosystem. One night, when we are setting up equipment in the middle of a dark forest, wolves begin howling not far from where we are. I and my colleagues Angela Dassow and Beth Smith are in a cheerful mood – there’s nothing quite like feeling that the animals you have tried so hard to understand are here around you, helping you along the way. But there is also some tension. All wild animals are potentially dangerous. Wild boar and rhinoceroses have provided me with my closest escapes in the past. But wolves too could possibly do harm. Beth turns to us with a nervous grin, and in her broad Lancastrian accent pronounces, ‘To be honest, I just want to get out of here alive.’ A joke, of course – she is an exceptionally experienced biologist of large carnivores, well used to stomping through the snows of Finland and the forests of Transylvania all on her own, tracking wolves. But there is a kernel of truth. Nature is unpredictable. It is not like our well-regulated lives of commuting to the office every morning. In the wild, we are far more helpless, far more susceptible to the inexorable imperative of all life to feed – feed on us, if necessary. The contrast between the highly controlled and reliable lives we lead in ‘civilization’, and the fraught, chaotic, and capricious natural world is often frightening. There is no need to fear wolves specifically, or to fear the world of the wolves. Fear is not a good basis for planning coexistence. How can we learn to recognize the needs of the predator – territory, mates, and yes, prey to eat – while not surrendering our own needs? Predators are vital for a smoothly functioning ecosystem. Can a deeper understanding of the behaviour of the wolf help us to strike a suitable balance?

Wolves howl to advertise their territory, to keep in touch with members of their pack, and because it makes them happy. It’s not a language of any sort, certainly not a language that we can learn to speak. But it’s communication, nonetheless. Perhaps we can tap into that communication. If wolves understand broad emotional themes when conveyed in their howls – if they do – then perhaps we can convey our own messages. Some farmers have tried (with little success) using recordings of wolf howls to deter the animals from their livestock. Surely that cannot work if we don’t know what message we are conveying – the farmers might be broadcasting a howl saying, ‘Come and eat here!’ But by uncovering the broad themes of meaning in howls – and by this I mean emotional cues – we can be a little cleverer with our methods. Playing howls that will be interpreted as a deterrent could be effective, and harmless. This has happened in Italy, where wolves deterred from farms survive even without preying on livestock, and are still playing their vital role in the ecosystem, controlling prey populations and balancing the fluctuations caused both by nature and by humans.

This is quite an astounding suggestion. It may seem that I am proposing ‘talking’ to wild animals. Patently, we cannot talk to animals that do not understand what a language even is, let alone what we mean with our language. But, of course, we talk to animals all the time, and we talk to those special relatives of the wolves more than to any other. Dogs are not wolves – they evolved from an ancient relative of the wolf, probably more similar to a jackal or a coyote than to the majestic, bison-hunting denizens of the Great Plains. But they and their ancestors share a lot in common with modern wolves. They are social animals, of course, living in packs, and forming close bonds with other members of their pack. And they also delight in social interactions. Just as wolves play and romp, adults indulging the pups with games of tug and pounce, so do dogs play, tug, and pounce with us humans. Wolves use howling to cement their social bonds, and typically drop whatever they are doing to howl whenever their colleagues do the same. Similarly, dogs know when we are talking to them: they prick up their ears and tilt their heads to understand what we are saying.

As deeply social animals, living in a world of family friendships, as well as vicious conflict with other families, wolves must say a lot to each other. When in the intimacy of their own pack, no doubt they communicate their pleasure and displeasure, their desires and dislikes, using a suite of subtle signals that we have yet to decode – even if our understanding of domestic dog communication gives us a head start. But what about that most thrilling of communicative behaviours: howling? Here, we can be quite unequivocal. Howling is not a language. There are no words or sentences, and no distinct meanings in the way that we imply distinct meanings all the time using our own language. But the concept is still familiar. Howls tell a story about how the animal is feeling: lonely (isolated), threatened (by other wolves, perhaps), or happy to be in a family group. We do the same. We can communicate just the same ideas using our tone of voice, or our posture and gestures. Howls cannot be detailed, because they are adapted to communicate over long distances. We do this as well. A well-placed ‘omg’, or even ‘wtf’ in a text message tells the recipient everything they need to know, even if we can’t put our finger on a precise meaning.

There is a fundamental lesson here that tells us much about who we are as humans, and what our relationship is to other animals. We were communicative before we had language, and we are still communicative, even without language. True, our brains have been modified almost beyond recognition by the fact that we can speak. So modified, in fact, that we find it difficult even to conceive of ‘meaning’ in any way other than that of words and sentences that mean something particular. But we still can communicate without direct meaning. We can still sit absentmindedly stroking a dog’s fur, or even holding hands with another human – communication, without doubt, but not meaning anything in particular. Just as a howl can be aggressive or social, so we can convey emotion by fixing our gaze on our dog in one way or another. Our communicative link with animals is still there, buried beneath our imperative to use words and language. We can still talk to animals, it’s within us. It’s just a different kind of talking from the one we think we know.

14.

2. Dolphin

Being underwater is probably the closest most of us will come to experiencing what it is like to be in outer space. Puny and helpless, we must rely on machines to allow us to breathe, and we move around with only the clumsiest of efforts. In neither the inhospitable frozen Arctic nor the jaguar-infested jungle are we as vulnerable as we are underwater. Personally, I am too enthralled by being underwater to panic – well, not panic too much, anyway. But certainly, there is plenty of reason to panic. Whatever is going on down there under the sea, it’s a world where we don’t belong, and where we’re not equipped to move, or even to breathe – and certainly not to communicate. And then, as if to underline the point, with almost obscene ease, a huge sleek figure slides past. Twisting and turning, exploiting all three dimensions as easily as we would walk down the street. Now upside down, now on its side, the massive creature turns a huge eye on you with a look not of hunger, not fear, but of curiosity. If it were hungry, it could take a bite out of you as easily as you could pick up a helpless snail from the ground. If it were afraid, it would simply swim away, and there would be nothing at all you could do about it. Nothing solidifies the sense that this is an alien world – not just one in which we don’t belong, but also one that we will struggle to understand – quite like being surrounded underwater by dolphins.

But if you spend any time at all in the water with dolphins, you quickly notice something else. Oppressive and smothering as the weight of water around you is, it is never silent. The animals almost never stop making sounds. And what sounds! Clicks, whistles, buzzes – and constantly changing all the time. An almost unimaginable exchange of communication between individuals. Because our ears are not built to detect the direction of sound in water, it’s hard to tell which animal is making which sound, and that’s made worse by the fact that they don’t open their mouths but make sounds deep inside their blowhole. Still, it’s clear that some kind of communicative exchanges are taking place.

Ask anyone which animals have a language of their own – whatever that means – and most people will say ‘dolphins’. There’s something about these creatures that causes us to rate their abilities far above those of other species – sometimes even above our own abilities. Some believe that dolphins are telepathic, that they are manifestations of a divine multi-dimensional alien intelligence, or just that they have a sophisticated language of their own, which we are too closed-minded to see. For me, dolphins are fascinating animals, beautifully adapted to their environment, eminently capable of exploiting their surroundings, and with the intelligence and communicative ability to understand (sometimes) the requests we make of them. This in itself makes dolphins worthy of study. To be honest, I’m more excited to study dolphins for these reasons than as the potential representatives of a powerful intergalactic government. Of all the hyperbole made about dolphin abilities, only one appeals to me, and that was written by Douglas Adams in his Hitchhiker’s Guide to the Galaxy:

15. A spectrogram of nine seconds of whistles from a group of spinner dolphins, showing the overlapping whistles of many different animals.

Man had always assumed that he was more intelligent than dolphins because he had achieved so much … the wheel, New York, wars, and so on, whilst all the dolphins had ever done was muck about in the water having a good time. But conversely the dolphins believed themselves to be more intelligent than man for precisely the same reasons.

Dolphins do seem to have fun. Just about all animals, from turtles to kittens, play, and scientists believe that play is an essential part of animal behaviour across the most surprising range of species.1 But even so, dolphins seem to do rather a lot of playing. This stands in clear contrast to most other animals. Consider a grazing animal such as a zebra. They eat a relatively innutritious food (grass), so they must spend an awful lot of their time eating to make sure they get the nutrients they require. OK, zebra play sometimes, frolicking in the savannah, but it’s not really a large part of their day. Now consider a lion. They expend tremendous energy chasing prey, but only briefly. Once they’ve caught the zebra (or failed to), they want to relax and take a break. Yes, cubs play, and adults play with them. But lions, like zebras, spend only the smallest proportion of their time playing. As I mentioned in the previous chapter, wolves spend a lot of time hanging out. There’s play involved in this too, but mostly it’s resting.

Dolphins are not like this at all. When you watch dolphins in the wild, they seem to spend a relatively small part of their time doing anything useful, like feeding or resting. Although most people have only seen wild dolphins above the surface, usually when they’re travelling as a pod, once you go underwater, a completely different picture appears. The animals investigate everything – especially you. They take great interest in their environment, sometimes even manipulating objects to find out more about them, and this interest and investigation doesn’t necessarily seem to serve any direct purpose. Sure, it’s good to know whether that weird creature blowing bubbles with a tank on its back is dangerous or not, but the inordinate amount of time that dolphins invest in investigations is a clear pointer to their intelligence – they must have the ability to make use of all this information, otherwise why would they spend so much time collecting it? And dolphins play a lot too. They snatch strings of seaweed from each other in a kind of game of tag, they even blow bubbles for fun, making smoke-ring-like shapes from their blowholes, and then poking their snouts through the shapes that they’ve made.2

Yes, dolphins are smart. But why are they smart? And where does that take us in our journey to understand animal communication? Are they really the most sophisticated animal communicators, as some people assert? Do dolphins have a language, and would we know if they did? Perhaps it’s better to approach the question of dolphin communication as we would approach understanding any other species – wolf, parrot, or even human. We want to know why dolphins communicate the way they do, what role this communication serves, and how communication shapes dolphin societies and dolphin relationships. Only that way can we really understand what’s going on with this most intriguing of animal communicators.

The sounds dolphins make

Sound travels well underwater, and so sound is the main medium that dolphins use to communicate. Except in the most pristine waters, you can see pretty much nothing further away than about ten metres, so vision is limited for communication purposes. Dolphins do have big eyes (if they weren’t big, they wouldn’t be able to see anything at all), and scientists have only just discovered that they also use chemical cues – essentially, it’s possible for them to ‘smell’ each other’s pee from the taste of the water (I do not advise trying this at your local swimming pool). But sound reigns supreme. Sound travels fast, with little distortion, and is easily produced and detected. Like bats flying through the darkness, dolphins use sound to find their way around, producing loud clicks and then listening for the pattern of echoes to tell them whether something’s in front of them, what shape it is, and even of what material it’s made. So, it’s not surprising, given all the constraints of living and navigating underwater, that dolphins have evolved sophisticated techniques both for producing complex sound and for hearing and interpreting it.

Those clicks, used for echolocation, are produced all the time. Underwater, you can hear them generated at a fairly lazy rate when the animals are simply swimming around, but then they become faster and more urgent when there are obstacles in the water, or if something appears that needs to be investigated more closely (like you, perhaps). Sometimes the clicks come so fast and furious that they sound more like a buzzing, and these sounds, called burst pulses, probably have some role in communication as well, rather than just in echolocation. The pattern of buzzes, the rate at which the clicks come, possibly even subtle differences in the sounds of the clicks themselves (imperceptible to humans), may carry some important information to the dolphins.

16. A spectrogram with rapid clicks (vertical lines) called burst pulses coming at a varying rate. Overlapping, in this case, with some whistles as well. Dolphins, making sounds from their two ‘nostrils’ independently, can produce two sounds at the same time, which is unusual for mammals.

But to be honest, we simply don’t know. Like many of the animals in this book, dolphins are incredibly difficult to study in the wild. In the same way that you simply cannot follow a pack of wolves if they don’t want to be followed, dolphins can simply turn their backs on you (or, perhaps more accurately, their flukes) if they so choose, and there’s nothing you can do about it. So, researching wild dolphin communication still has a long way to go. But there’s something special about dolphins that makes them very different from wolves, or chimps, or almost any other animal. That same playful nature I mentioned above means that – sometimes – dolphins actually cooperate with you. Sometimes, either in the wild or in captivity, dolphins can be persuaded to take part in your research; to answer questions, almost.

Scientists have used this cooperative tendency in dolphins for decades to probe the meanings of their sounds. But in all those years, most of the research into dolphin communication has been directed at one single kind of sound: the whistle. I’m not saying that the other sounds that dolphins make, burst pulses in particular, don’t have a role in their complex communication. I’m sure that they do. But I’m going to concentrate on whistles, just as the last chapter dealt with wolf howls and not their growls and whimpers, because dolphin whistles illustrate very well the way that these animals have evolved a communication system to suit their needs – and this helps shine some light on exactly what those needs are.

The whistle: the core of a dolphin’s communication

Dolphin whistles are just what the name implies: a high-pitched tone that goes up and down in a complicated way, and it is that diversity in the whistles that has fascinated scientists, and absorbed huge amounts of time and effort into answering two questions: why are these whistles so diverse and what do they mean? Dolphins whistle pretty much all the time. Not as often as they produce echolocation clicks – they need the clicks to find their way around – but fairly constantly nevertheless. As I mentioned, they don’t whistle with their mouths as we do, but then that’s not surprising, because they don’t breathe with their mouths as we do either. Dolphins make all their sounds through their blowhole – their nose, effectively. Another difference between the whistling you’re used to performing and the whistles that dolphins make is that dolphins can recirculate the air they use for making sound, so you don’t necessarily see bubbles coming out of the blowhole of the vocalizing animal. This is terribly frustrating when you’re looking around hoping to figure out who is saying what to whom, but it makes sense, when you think that these animals must hold their breath as long as they’re underwater.

Dolphin whistles and wolf howls have a lot in common. Slowed right down, they sound very similar, and in fact a howl and a whistle differ only in pitch and duration. And it is no coincidence that these two signals have similar properties, and even look the same on spectrograms. Sound might travel very well underwater, but the ocean is still a noisy environment, and there’s a lot of interference – precisely because sound does travel so well. Dolphins aren’t the only animals making use of sound to communicate, and the incessant snapping clicks of different species of shrimp, in particular, is a constant background noise that tends to drown out everything else. Add to that the sound of waves, and myriad other creatures, and you see that getting your message across is even harder for dolphins underwater than it is for wolves in the mountains and valleys of Yellowstone. If you’ve got something complex to say (and by complex, I mean something more than ‘I’m here!’), then your signal must be faithfully reconstructed by the listening animal, despite all of the interference that occurs along the way. And as with wolf howls, the way to do that is by using a single note that varies up and down in pitch. Concentrate your sound energy into a single frequency, but vary that frequency up and down to represent different kinds of messages. That’s precisely what a whistle is.

So, as well as simply making a whistling sound, if they want to send complex information, dolphins must have very precise control over the pitch of the whistles that they make. It’s those up-down changes in pitch that will, after all, be the only thing that the listening animal can distinguish about your whistle. And indeed, dolphins have very precise control over their whistles, so that their repertoire can be very large – they can produce a huge variety of whistles and can quite easily copy the whistles produced by other dolphins, or even by humans. Some kinds of complex whistles they can make over and over again and they sound almost the same each time.

17. Spectrograms of ten similar – but different – whistles produced by the same dolphin.

Well, not quite the same each time. You’ll notice that the whistles shown in the diagram (all from a single dolphin) differ slightly. Those subtle differences point to one of the biggest problems in studying complex animal communication, not just in dolphins but also in many different species. It’s all very well when an animal produces discretely different – clearly different – kinds of sounds: whistles vs clicks, for instance. Anyone can tell the difference between a whistle and a click. But more often, an animal’s sounds of different kinds merge into each other; they are graded, rather than discrete. When does a cat’s cheerful meow become an angry meow? You might be able to tell the difference between your cat happily curling up on your lap, and angrily wanting to be fed – the extremes are easy to distinguish. But between those extremes, the sounds gently morph from ‘happy’ to ‘angry’, and there’s no clear dividing line. Such graded calls pose a problem to interpreting animal communication, because we don’t know where the animals themselves draw a line (if they do) between one meaning and another. Not yet, anyway.

Dolphin whistles, then, are almost infinitely variable. If no two whistles are exactly the same, and yet we want to investigate whether whistles have meaning, how can we describe whistles in a way that captures their variation in any sensible way? One interesting approach I’ve used to measure this in the past is by comparing whistles to musical melodies. Even those of us who are not particularly musically competent can recognize tunes, without being able to name the notes themselves, or even the key in which the tune is played. Why? We seem to recognize the up-down pattern of the pitch, and a similar thing appears to be happening in dolphins. Back in 1975, a man named Denys Parsons published a method for classifying tunes, based only on their up-down pattern. Instead of notes (A, C#, etc.), a melody is represented only by the direction of change from one note to the next: up in pitch, down in pitch, or remaining the same. This Parsons code greatly reduces the information in a tune – you’d never be able to reproduce the tune itself from a Parsons code, but you could recognize it.

18. Mozart’s K265, (variations on ‘Twinkle Twinkle Little Star’), and above it, the Parsons code, represented as ‘up’ (U), ‘down’ (D), and ‘same’ (S).

Humans can recognize a tune from its Parsons code, but what’s amazing is that dolphins seem to recognize that two whistles, which are slightly different but have the same Parsons code, are actually the same whistle.3 This very neatly underlines that when dolphins hear whistles, they’re doing something similar to us – listening for the up/down pattern of pitch, and using that to interpret what the whistle means.

Animals that give themselves names

So, what are dolphin whistles actually for? There may be many meanings, possibly even meanings that blur into one another, just as the differences between the whistles are graded and blurry. But surely these whistles serve some purpose. Surely they represent something.

We do at least understand one thing about dolphin whistles: we know that each individual dolphin produces a certain kind of whistle that represents its own name.

That fact alone is absolutely extraordinary. As far as we know today, there is no other species in the world – none, bar humans and dolphins – that naturally, and as a part of their regular communication, give themselves names. Yes, you can teach your dog to recognize her name. Yes, many animals can recognize individuals by the sound of their voice, which acts as a kind of individual ‘signature’. But there is something deeply and fundamentally different about creatures that can invent unique sequences of sounds to refer to themselves – sequences that are also recognized and used by others. At least it should make you question – and we can’t be sure of the answer to this, one way or the other – whether these animals actually understand themselves as individuals, different from other dolphins, who also understand that they themselves are individuals.

Signature whistles, as these name-like vocalizations have been called, have been studied for decades. Although early researchers speculated that these whistles might function as names, it took a long time before that became the scientific consensus – and rightly so. You may be sceptical of what is, after all, an exceptional claim. The first piece of evidence was that, while any particular dolphin tends to make a wide range of sounds, each animal has one particular whistle that they make more than any other – and that whistle is quite distinct from the whistles of other animals. In itself, this is not particularly strong evidence – birds also sing individually distinctive songs; why do we not think that they use songs as names? It was also fairly interesting that when wild dolphins in the Sarasota Bay in Florida were caught temporarily for health checks and so on, becoming isolated from other dolphins in their pod, they would make their signature whistles over and over again, as if crying out for help, or alerting the other members of their pod that they have become separated from the rest. Distress calls are a well-recognized behaviour among many species, but it’s unusual that dolphins cry out using an individually specific whistle, not a general distress call. Some more convincing evidence came from the fact that mothers that become separated from their calves use their own signature whistle to call for their baby. Adult animals sometimes seem to respond to a friend’s signature whistle with their own – slightly different – version, as if to confirm that they know who is addressing them. And in a remarkable set of experiments, one researcher showed that dolphins responded excitedly when played a recording of the signature whistle of an animal they hadn’t seen for years. Perhaps most convincingly, by looking at the way that baby dolphins develop their own unique signature whistles, we can see that they seem to copy their mothers to some extent, but ensure that their own whistles are sufficiently different to distinguish them as individuals. The scientific community is pretty confident at this stage that we really are talking about an animal with names.

19. The signature whistles of five of the dolphins at the Dolphin Reef research centre in Eilat, Israel.

Just why dolphins are so exceptional among animals in giving themselves their own names is a little harder to explain. But the answer really must lie with their social organization. Although there are many different species of dolphin, the most studied – the bottlenose dolphin and the Atlantic spotted dolphin – both live in societies that are described as ‘fission-fusion’. That means that, while the greater circle of acquaintances of a particular animal may be fairly fixed, that circle is fluid. Large groups split up (fission) and then come back together (fusion), and then split up again into smaller groups, often driven by the kinds of resources that are available, which include both food and potential mates. So, you might not have seen Rajah for a long time when you finally meet him again, but it’s a good idea to recognize him when you do, because you may well have worked together very effectively in the past. Or you might hate each other’s guts. Either way, it’s good to know who’s who.

Dolphins are very cooperative, coming together to hunt fish effectively, for instance, and recognizing your friends and enemies helps keep that cooperation running smoothly. Perhaps the most surprising use of signature whistles in a fission-fusion dynamic was shown recently in groups of male dolphins, who cruise around looking for females to harass.4 These male alliances seem to be organized hierarchically, and they use their signature whistles to advertise to which group they belong, and at which level. It’s as if they are advertising not just to which gang they belong, but which region, and which local chapter. Small groups of males from the same gang will come together if necessary, but won’t mix with males from other gangs. And all of this seems to be mediated by signature whistles.

When you cooperate a lot, you need to know who your partner is. If you live with the same family all the time (as wolves do, for instance), then it’s not hard to remember who’s who. But when you have the vastness of the ocean at your feet (or your flippers), and the group of animals you work with is constantly changing, then the need for a clear and specific way of recognizing one another is a very powerful evolutionary force. And, it seems, this is why signature whistles have evolved. Crucially, it’s not enough simply to recognize the whistles of your friends and enemies – you also have to understand that these are separate animals, each of whom might potentially elicit a different reaction from you. You need to know how to respond when you meet another animal: is he a friend or an enemy? That kind of complex social intelligence proceeds hand in hand with the ability to communicate the same kind of information. Social animals – wolves, chimps, dolphins, hyenas, and others – must have the ability both to recognize and respond differently to different individuals, and to make themselves recognizable. Communication and sociality go hand in hand, time after time. It’s no coincidence – no coincidence at all – that the only two animals on this planet that use names both live in complex societies where recall and identification of individuals is essential to the effective functioning of that society. It’s an interesting question whether our own ancestors lived in such a fission-fusion society, and whether it was the demands of managing and remembering a wide range of relationships that pushed the evolution of human language. I’m going to have more to say about this in the chapters on chimpanzees and on humans.

It’s not just about names

So, we’ve talked a lot about signature whistles – because they do seem to be genuinely exceptional in all the animal kingdom. But what about all the other sounds dolphins make? What about their other whistles, because, in the wild, signature whistles make up only a minority of a dolphin’s repertoire? To date, every other kind of whistle that isn’t a signature whistle has been lumped into the rather unimaginatively named category of ‘non-signature whistles’. What do they mean?

No idea. Really. No one knows. It’s a huge gap in our understanding of dolphin communication, the role that it plays, and the meaning of the different sounds. Of course, ‘What does a particular non-signature whistle mean?’ isn’t a very precisely posed question. As we saw before, whistles are infinitely variable. We have a pretty good idea of what counts as the signature whistle of a particular dolphin, because we hear it repeated again and again by the same individual. But non-signature whistles are never quite the same twice – does that mean that they are two separate messages with separate meanings? Or that they are two sounds that mean the same thing, with insignificant differences between them? Or perhaps our idea of meaning, tied as it is to our experience with the words and sentences of our own language, isn’t a particularly helpful way to view these whistles, and the differences between them, both subtle and coarse. Broadening our perspective on what form meaning must take is absolutely critical when trying to understand the communication of non-humans.

Take two whistles that sound similar, but (to us) are noticeably different. One possibility is that they may refer to, for example, two different species of fish. This would be the conventional human way of looking at communication through the lens of words and sentences. One whistle means ‘mackerel’, and the other means ‘mullet’. If only animal language were that simple, we would have decoded it already! An alternative interpretation is that both whistles might mean ‘mackerel’, but one whistle implies ‘Mackerel, yum’, while the other implies ‘Oh no, not mackerel again!’ In this case, there’s clearly different meaning to the different sounds, but that meaning isn’t conceptually different, rather there’s a difference in nuance. This seems far more plausible: that the emotional state of the animal vocalizing dictates at least part of the acoustic properties of the sound. We humans do this ourselves, of course, and there is no doubt that at least some of the meaning in our own language is communicated by subtle nuances that are emotionally shaped. We can even invert the meaning of a sentence completely using slight variation in intonation (‘Oh! Broccoli for dinner!’ vs ‘Oh. Broccoli. For dinner …’) However, we struggle to consider this the defining essence of language. True, the richness of our communication is greatly enhanced by these nuances, but we could still convey the overall meaning of the message without it. If dolphin whistles that are similar but different represent messages with differences in nuance, would we want to call that ‘language’? A third possibility is that perhaps the dolphins don’t even notice the subtle differences between similar whistles. Perhaps all of those whistles, that to us are clearly slightly different, just mean the same thing. Perhaps they mean, ‘Hi, I’m here!’ Which of these three interpretations of the wide range of non-signature whistles is the correct one isn’t easy for scientists to determine. Quite likely, the only way to resolve this dilemma is to ask the dolphins themselves, and I will talk about that later. But I do want to spend a moment on that last possibility. Might we be overestimating the dolphins a little bit? Perhaps their communication is actually trivial?

The ‘Hi, I’m here!’ phenomenon is very widespread among animals that live in groups. Known as ‘contact calls’, these sounds are made, almost continually, by many different species, with the sole purpose of letting everyone else know that everything is OK. Meerkats are delightful little creatures, and once they are accustomed to human presence (achieved by the patient researchers at the Kalahari Meerkat Project5 through the simple strategy of feeding them with scrambled egg every morning), they pretty much ignore you and get on with their business. So, it’s a fascinating way to spend a morning, lying on the ground watching and listening to these tiny mongooses going about their day. And they make sound all the time. Little grunty squeaks that you wouldn’t even hear unless you were right up close. It’s a comforting and reassuring background noise, and that, of course, is exactly the purpose. A meerkat can have his head stuck down a hole in the ground, looking for centipedes, but as long as he can hear the gentle chatter of other meerkats in the vicinity, he knows there are no predators around.

20. Meerkats, always alert and always cautious, rely on a constant chatter of contact calls to reassure them that the surroundings are safe. If so reassured, they can be pretty friendly, like these two I met in the Kalahari Desert.

Is it possible that the continuous and ever-present whistling by a pod of dolphins fulfils the same role? Perhaps there is no fantastic meaning, no deep understanding, just a constant chatter of ‘I’m here, it’s OK, nothing interesting going on.’ I daresay there’s a certain amount of truth in this idea. Certainly, whatever the true purpose of a constant stream of non-signature whistles, they will probably also function as reassuring contact calls. But non-signature whistles being solely contact calls is a somewhat unsatisfying explanation. They are simply too varied, too complex. Contact calls are usually simple, easy to produce, and also low volume – you want to reassure your friends, but not to alert any predators nearby. One thing we can look at for clues about the role of a certain kind of vocalization is where the variation comes from. For instance, we know that the contact calls of different meerkats in a group are noticeably different, and contact calls are noticeably different between groups. That makes sense – you can use the sound of the contact call to tell you both who’s nearby and whether you’re in the right group. However, dolphin non-signature whistles don’t seem to be specific to a particular animal, or to a particular pod (although, to be fair, we haven’t yet researched this nearly as much as we would like). So that variation seems to be more than just individual idiosyncrasy, or a group ‘theme song’. There seems to be something more going on with dolphin whistles – more than a mere ‘Hi, I’m here!’ – although it’s probably not quite as much as a straightforward conversation.

One of my students, Tan Morgan, has looked at whether certain types of non-signature whistles are used preferentially in different social contexts. We generalize the whistles into very broad categories, that way escaping from the problem I discussed above of graded calls, and whether two similar whistles mean the same thing, or something different. So, we might look at whistles that go up in pitch, whistles that go down in pitch, and whistles that go up and then down. When we categorize whistles into such broad categories, we do seem to see that some are used more in different contexts than others: when playing, interacting with humans, or chasing each other, for instance. Of course, that doesn’t mean that a particular kind of whistle actually means, ‘Look at me, I’m playing!’ But it is somewhat more satisfying to view dolphin non-signature whistles as reflecting general states of mind or general activities, or sending general messages, rather than as representing words in a way that could be translated into English. Or from English into Dolphin.

But do dolphins use words?

Scientists can be rather harsh in dismissing appealing descriptions of animal behaviour – the kind of thing that makes animals seem rather like us humans, in fact. We would like to believe that dolphins have their own language, as we do. Am I being harsh by denying that they do? One problem, of course, is that I haven’t yet defined what I mean by ‘language’ (and nor will I, at least, not just yet). For the moment, it’s easier, and more rigorous, to constrain ourselves to talk about specific parts of language, which we may or may not see in different animals. When it comes to dolphins, we can ask whether dolphins have words. When they communicate with each other using such a complex repertoire of infinitely graded whistles, are they communicating with anything that we could describe as a lexicon? There is a dilemma here. On the one hand, whistles are graded, and so there is no clear distinction between one whistle and any other. On the other hand, we know that the dolphins use signature whistles that do have clear and distinct meanings. In that sense, dolphins already have the largest known vocabulary of ‘words’ of any wild animal, so far as we know. But is that use of discrete sounds extended by the dolphins to represent discrete concepts? Does one whistle mean one word, and a different whistle mean another word?

We are accustomed to thinking that a language is made of words and sentences, and that those words are distinct and clearly defined. If I say ‘cat’, no one should be under any doubt that I am referring to the carnivorous animal (perhaps domestic), and not to a ‘bat’, which is a nocturnal flying mammal. There’s a clear distinction between the two words, and not a gradual transition between the two. Indeed, if you try to say a word that’s somewhere between ‘cat’ and ‘bat’, you’ll probably end up with a nonsense sound – or possibly the name of another animal, like ‘rat’. Notice, though, that ‘rat’ is another distinct category, definitely not ‘halfway between a cat and a bat’. Words are, by their very nature, distinct and well defined. That is what we think of as the foundation of language – clear, distinct concepts that can be encapsulated in a single symbol: a word.

Now that doesn’t have to be the case with dolphins. Although signature whistles are distinct, there doesn’t appear to be any clear division between one non-signature whistle and a different one – they all merge together into a continuum of ‘similar but different’. Signature whistles are crafted to be different: as a dolphin calf matures, her signature whistle settles into a form that is pointedly distinct from those of the animals around her. Not so with non-signature whistles, which remain continuously graded. And so, it seems unlikely that most dolphin whistles are words in the sense that we understand. That doesn’t mean that they don’t have meaning – it doesn’t even mean that they aren’t language. But it means that whatever is going on there, it’s not something that we’re just going to be able to translate, as we would translate ‘cat’ (or ‘bat’, or ‘rat’) from English into French (‘chat’), Vietnamese (‘mèo’), or Uzbek (‘mushuk’). By constraining ourselves to think that an animal is using words in the way that we do, we might be missing out on some of the most complex communication in the animal world. It’s one of the hardest obstacles to overcome when we try to put our minds into the animal mind. Mostly – and certainly in dolphins – there just doesn’t seem to be that clear distinction between different sounds that might represent different concepts. This is crucial to bear in mind when thinking about dolphin communication in particular, but it’s well worth remembering about other animals as well. Just because we’ve developed a language based on distinct words doesn’t mean that is how others must communicate.

It’s interesting to reflect that both wolves and dolphins have travelled down an evolutionary path that has constrained them to communicate with the same kind of pitch-varying signals. The physical constraints of their environment admit no other possibility. If you want to send a message over the mountains, or through the waves, this is the way to do it. Of course, it’s the social structures of wolves and dolphins that also have directed the evolution of their communication – octopuses are intelligent too, and they live underwater, but octopuses don’t whistle – they don’t seem to have quite the same social need to. But once a social animal has developed a communication system that suits their environment and their relationships well, then that same system continues to constrain their cognitive evolution. Whistles, as we have seen, don’t lend themselves well to creating discrete categories. On the contrary, the very advantage of whistling (a reliable transmission of general ideas over long distances) makes them very unlike words, which are clear-cut and unequivocal. So, it’s possible that both wolves and dolphins have travelled down evolutionary pathways that have closed doors which might otherwise have been open for further cognitive and communicative evolution. It’s true, as Douglas Adams said, that dolphins don’t need the wheel, New York, and wars. But one of the reasons that they don’t need these things (and they just muck about in the water having a good time) is that their society would never be able to evolve to take advantage of such technological gems. They just don’t have the words.

Or perhaps I am completely wrong. Perhaps whistles do have meanings like words. Could that be possible?

Translating dolphin into human

When I was young, I was enthralled by the science fiction author Arthur C. Clarke’s novel Dolphin Island. Capitalizing on the widespread enthusiasm that existed at the time (in the 1960s and 70s) for understanding ‘dolphin language’, it tells the story of a young boy shipwrecked on an island in the Pacific, where scientists are developing a computerized device that will allow us to understand – and speak – dolphin language. The device, waterproof and wearable on the wrist, contains a series of buttons, each of which will transmit a different dolphin ‘word’. Now, decades later, and after plenty of research of my own, the story seems ridiculous, or at the very least, hopelessly optimistic. The idea that it is possible simply to translate, word for word, Dolphin into English, or English into Dolphin, seems to fly in the face of everything that we’ve learned about dolphin communication in the last fifty years. Not to mention that the idea smacks of arrogant human centricism. Why should dolphins have a language just like ours? Are human languages really the template for the way that animal communication must work? Because English has words and the Tagalog language of the Philippines also has words, clearly Clarke also thought that dolphins should have words too.

But before we mock some excellent and entertaining science fiction, we should ask: can we be sure that such a device is not possible? There are a number of scientists today still pursuing Arthur C. Clarke’s dream – some rigorously, and some more speculatively. Among the leaders in this field is Denise Herzing, who has studied spotted dolphins in the Bahamas for decades. Together with her team, she has developed an interactive device that both plays sounds underwater and recognizes the dolphin responses, playing them back to the user’s headphones in English. However, it’s crucial to realize that this research tool is not a dolphin translator. Instead, Herzing uses this to train dolphins to recognize relatively arbitrary whistle-like sounds that will (with sufficient practice) come to represent specific objects – like sargassum, a kind of seaweed that the dolphins love to play with in the wild. True, it’s still a stunning breakthrough to be able to communicate with dolphins in their natural environment – both to tell them things (‘Bring sargassum!’), and to hear their responses. In reality, this is no different from training a parrot or a chimpanzee to understand human words – which they can do, and which is both impressive and important. But, of course, this does not give us a direct window into the communication of the dolphins themselves. We still have no idea whether they have a special whistle for sargassum – we know only that we can train them to associate a whistle we invent with that same object. This ability to learn, to understand, and to respond to human requests is nonetheless a crucial feature of dolphin cognition, and one that I’ll have more to say about later.

Other scientists have taken a more adventurous approach. In today’s world of big data, and sophisticated artificial intelligence algorithms, there’s a tendency to think that any data problem can be solved if you put it in a big enough computer running a suitably complex machine-learning algorithm like a deep neural network. Many groups around the world are looking at translating dolphin (and also humpback whale) vocalizations by feeding vast amounts of recordings into powerful computers and hoping that some kind of understanding will come out of that. Maybe it will, maybe it won’t. My own feeling is that I regret any attempt to understand animal communication that takes us away from the animals themselves. If there is a code that needs to be broken, then perhaps artificial intelligence has the answer. But if dolphins are communicating not in a code, per se, if there is no straightforward mapping between the sounds that they make and the meanings that they want to convey, then the big-data machine-learning approach is unlikely to provide much insight. It seems to me far more reasonable that our task should be to understand the nature and the reasons behind the communication of these animals, and only then will we be able to know what kind of information might exist, and how to look for it, rather than hoping for human-like information, and searching doggedly for what we want to find.

Before we begin to rush into attempts to translate a communication system (i.e. to force it to conform to the kind of communication system that we humans use), it is important to attempt to identify what features of communication the animals themselves prioritize. We know that individual identity, for example, matters a great deal to dolphins. We know this because of their truly unique system of signature whistles, which really has no known parallel anywhere in the animal world (apart from us, of course). We also think that we understand why individual identity is so important for them to communicate to each other. In the vast ocean, dolphins live in small groups that are only subsets of their complete list of acquaintances. Travelling and hunting with one set of animals this week, and maybe with a different group next month or next year, they are constantly changing their social circles. Thus, recognizing others for who they are – friend, enemy, family or stranger – is of prime importance. This is no mean feat, requiring not just sophisticated communication, but also sophisticated brains that can keep track of so many colleagues – probably many tens of individuals – over years and decades. I’ve never tested, but I wouldn’t be surprised if a dolphin’s memory for names and faces is better than my own (which is fairly awful). Beyond that, we know that dolphins cooperate. They cooperate in hunting – herding fish together, for instance – and they cooperate in defending themselves, both against members of their own species (such as marauding gangs of males intent on coercing females to mate), and against other species (including other larger species of dolphin, who will take the opportunity to bully and harass smaller animals). This cooperation is probably mediated by communication – not unlike the story of the fight between Yellowstone wolves in the previous chapter. But the amount of communication necessary for these interactions is only marginally greater than what we see in wolves. So far, I’ve not described anything about dolphins that means they really need a language as such.

There are a couple of important differences between wolves and dolphins, however. For one thing, whereas wolves must always be on the lookout for aggressive incursions by other packs, and occasional threats from grizzly bears, they are for the most part top predators, and so their social cooperation is directed primarily at hunting, defending their territory, and raising young. On the other hand, dolphins (or at least the ones that we usually think about: bottlenose dolphins and spotted dolphins, in particular) are quite definitely under threat from larger predators like orca. In some ways, dolphins are better compared to coyotes than to wolves, and this perhaps drives their communication to be somewhat more complex. But the other crucial difference between dolphins and wolves is that dolphins do seem to be very communicative during their play. That is, while wolf play is generally highly ritualized, with unequivocal signals (for example, play bows, with which any dog owner is familiar), dolphin play seems to be much more varied. I’ve already mentioned bubble rings, and sargassum games, and dolphins do seem to enjoy a lot of object play, communicating all the while. It would be a mistake to consider communication as something that evolves only for ‘serious’ interactions – in fact, the complex communication we see in dolphins might genuinely be serving a primary purpose of facilitating playful interactions. Play allows animals to experiment, both with the world (practising hunting) and with other animals (testing out social interactions). The precise benefit of animal play, and why it is so widespread, isn’t as clear as you might think initially – ‘play is fun!’ isn’t enough of an answer. But it does seem to be the case that animals that have a lot of complex interactions (wolves, dolphins, humans …) play a lot. Whether that is because playing is necessary for a complex society, or whether animals with large enough brains to form a complex society must play to keep those brains healthy, we don’t know. But in a large and complex social group, play would seem to be vitally important, and can bring concrete benefits, almost as much as foraging or defence.

How to ask a dolphin a question

There is one key feature of dolphin behaviour and communication that I’ve alluded to so far, but which we haven’t yet addressed in enough detail. And that is their remarkable ability (and willingness) to cooperate with humans in our scientific investigations. Perhaps it is the dolphin’s willingness to play with humans that, more than anything else, has driven our sense that there is something more than mere animal instinct hiding behind their fixed grin. In fact, the ability of dolphins to learn what we want from them is both remarkable and crucial in understanding what and why these animals communicate.

Like many people, I’m uncomfortable with the idea of keeping dolphins in captivity. There’s something that feels wrong about confining such an intelligent creature, used to the full freedom of the sea, to a tiny and artificial enclosure. To be honest, I’m uncomfortable with the idea of zoos in general, even though I spent much of my childhood running around them, and I have no doubt that these were highly formative days for me and my future career. In fact, this is an important point that we mustn’t forget. Most humans, certainly in the Western world, will never see very much in the way of wild animals in their natural habitat. In the case of those who live in a big city, not much beyond some pigeons and songbirds, and perhaps the odd urban fox. Zoos, for all their disadvantages, do have a role in instilling some sense of wonder at the animal world. When I do go to zoos these days, I spend most of my time watching the humans, and particularly parents with their children, rather than looking at the other animals. What are they gaining from the experience? Sometimes parents are rushing their offspring around from one enclosure to another, doing little more than naming the different creatures. But it’s not uncommon to see children perched outside an enclosure, staring with unbreakable fascination at the animals within. This is, I think, a positive outcome in an otherwise undesirable situation.

What about dolphins in captivity, though? What do they think about their situation? I have considerable sympathy with activists who are pushing for an end to keeping captive dolphins, but of one thing I am sure: if dolphins are kept in captivity, they must be kept stimulated. The kind of entertainment shows that are put on for the public, with dolphins jumping through hoops or balancing balls on their snouts, are of vital importance to the animals themselves. I have little doubt that a dolphin would rather be free in the sea, where movement is not limited by walls, but extends through the vast three-dimensional space of our watery world. Not just the ability to go anywhere, but the almost unlimited range of stimuli: fish and other animals to see and chase, sounds to interpret, different tastes and currents in the water – who knows what is important to a dolphin’s senses? But if dolphins are not free to occupy their minds by roaming the diversity of the open sea, then the next best thing is to be learning new activities, new interactions with their trainers, and new tricks to perform. It is part of the remarkable nature of these animals that they appear to flourish with mental stimulation, and with new challenges. It’s extraordinary how enthusiastic dolphins appear to be about learning new tricks. In captivity, training is never done using any kind of punishment – only positive reinforcement will work because, of course, it’s easy for the animal simply to stop cooperating if it wants to. I’m not saying that abuse never happens, but that all the trainers I’ve known and worked with are engaged in a genuine two-way process, where the animals learn to behave as the trainers want because this is an engaging and exciting way to keep them busy, in a world that is otherwise devoid of diversions.

But for the purposes of this book, there are two important outcomes of this unusual aspect of dolphin behaviour. Firstly, we should ask ourselves, why are these animals so keen to cooperate, so keen to learn and to play? What is it about dolphins that makes them seek out interactions with humans? In captivity, there’s no mistaking the excitement experienced by dolphins who understand that you’ve arrived at the side of the pool to start carrying out some behavioural experiments. But even wild dolphins have come up to me as I’ve been setting up an experiment, bobbing their heads out of the water and looking curiously at me and my equipment. And then the second question is, given that dolphins do find participating in our training regimes, and even in the corresponding behavioural experiments, so appealing, what can we discover about the dolphin mind, and even about dolphin communication, from taking advantage of this quite remarkable sense of cooperation from a wild animal? For all the similarities between wolves and dolphins, this behaviour is a striking difference. Wolves in a zoo will not actively seek to cooperate with humans in scientific experiments. Try to ask a question of a wolf, and she’ll just sit down and stare at you. Of course, we can still do experiments where, for instance, we play a particular kind of howl and look to see how the wolf reacts: turns to face the speaker, howls in response, ignores the sound, etc. But we rarely get the chance to ask a direct question: ‘What is this?’

Back in the 1980s, scientists in Hawaii were training dolphins to cooperate in their experiments, and getting results that are, even now, impressive and surprising. For example, once trained to recognize that certain gestures referred to certain objects (e.g. ‘hoop’), the animals could answer questions about those objects, even if the objects themselves weren’t present. So, one dolphin (Ake) could press one paddle to answer ‘yes’, or a different paddle to answer ‘no’ when asked the question, ‘Is there a hoop in the pool?’6 Of course, this is tremendously interesting from the perspective of animal cognition and language – very few species of animals can talk about objects that aren’t present. But what interests me just as much is the very fact that Ake took part in this experiment at all. When researching animal communication, I spend much of my time analysing the sounds that animals make when they are more or less left to themselves in the wild. Experiments – where you can actually ask a question of the animal – are the exception rather than the rule.

21. An experimental setup where a dolphin is played different sounds, and asked to choose whether they are ‘the same’ or ‘different’.

Dolphins appear keen to participate in these kinds of experiments. After a bit of training, so that they understand what is asked of them, the scope for probing just what a dolphin can and can’t understand is almost limitless. My colleagues Sara Torres Ortiz and Angela Dassow and I are training two captive dolphins called Achilles and Ulysses to answer one of the hardest questions that we have about dolphin communication. Just what is the difference between two similar whistles? Are they basically the same? Or do they mean something different? In no other species has it been possible to delve so deeply into the way that the animals themselves perceive their communication.

Why are dolphins so keen to be active collaborators in our scientific quest? Clearly, they don’t understand what we’re trying to do and why. I think that the answer lies in their linguistic abilities themselves. In the next chapter, we’ll hear about a remarkably similar phenomenon, where scientists trained a parrot to answer direct questions too. Although most people don’t think that either of these two species actually has and uses a language of their own, there is some level of underlying linguistic ability that allows a certain amount of sharing of intent between us and them. You don’t need to be able to write dramatic plays and discuss the weather to understand concepts like same/different, presence/absence, or even the idea that a verb can be combined with a noun: ‘Bring ball!’ as opposed to ‘Bring hoop!’ Indeed, perhaps the most important insight from dolphin research is not what they are capable of doing (remarkable as that is), but the fact that they are capable of doing it without having a language of their own. There is something going on in those dolphin brains that allows them to grasp concepts that we feel must be inherently linguistic, like the fact that a request to bring a ball is similar but different from the request to bring a hoop. Or that word order is important: ‘Bring the ball to the hoop’ vs ‘Bring the hoop to the ball’. These are things that seem almost human in intelligence – but that’s precisely because the language manipulation that we see in dolphins is so terribly rare in the animal world. And more than that, the dolphins themselves seem to recognize this commonality between our species; it is quite natural for them to participate and cooperate, because we are drawing on common mechanisms and common interactions, which they themselves use with others of their own species.

So, do dolphins have a language or not? They certainly have the unusual ability to call each other by name, which implies that they can use symbols to represent objects (individuals), even those that are not actually present at the time. This is one of the fundamental features of language – being able to have representations of ideas, and to convey those representations to others. So, one point for dolphins. But, as far as we know, they don’t seem to use their whistles to represent objects beyond their signature whistles. What’s more, their whistles aren’t particularly well suited to represent distinct concepts. Researchers will continue to look at the information content in dolphin whistles, and maybe we will find more cases of symbolic representation. We know from training dolphins that they can associate particular whistles with particular objects, and we hope to discover whether they actually do make that connection.

Dolphins seem so exceptional. You might think that they are too exceptional to tell us much about the way that other animals communicate, and the way that communication and language has evolved. You might wonder whether dolphins are too unusual, too much of an outlier to allow us to draw from them really generalizable conclusions. But dolphins are actually not that unusual at all. Everything that we see – their uncanny ability to understand our commands, their unique use of names for individuals, their constant, complex chattering – is consistent with what we know about the way they live their lives. It’s nothing unexpected. Animals that live in such large groups, and have such complex interactions in those large groups, must be able to refer to others, to distinguish between objects, to pass information back and forth. They are not communicative for our benefit. Rather, given their way of life, they could not be any other way. More correctly, as the ancestors of modern dolphins evolved and adapted to living in the sea, foraging successfully and avoiding fearsome large predators, there was an unexploited opportunity that could be taken advantage of – but only if you’re smart, cooperative, and communicative. Those animals that slowly, generation by generation, took advantage of that opportunity consequently became smarter, more cooperative, and necessarily more communicative. The way that dolphins are now reflects the way that their ancestors needed to be.

It’s tempting to think this means that dolphins are in some way retracing the steps that our own ancestors took – living in larger more complex groups, evolving more sophisticated brains and more sophisticated communication, and eventually becoming modern humans with the wheel, New York, and wars. But that’s not at all the case. Dolphins (or any other species) aren’t ‘on their way’ to becoming human. Our own adaptation to surviving in the world, and in particular, our language ability, isn’t something towards which other species are striving. In fact, neither were our ancestors striving to become modern humans; they simply adapted with changes that suited them best at the time. Dolphins need to communicate enough to cooperate, to fish and to forage and to defend themselves. We can confidently say that dolphins don’t really have a language by looking at the way that they live in the wild – precisely because they don’t have those technological advances that Douglas Adams pointed out. But the logic is the other way round from what you might have thought. It is definitely not the case that dolphins don’t build machines because they don’t have a language. Rather, they don’t have a language because they don’t need to build machines. That is the point of this book. We need to think about what animals need, and not what we’d like to think that they have. No, dolphins have it pretty much sorted out for themselves. Their level of intelligence and their communication is suited for what they need today, not as part of some grand plan. So, they can’t speak quite like us. But at least they muck about in the water and have a good time.

22.

3. Parrot

Someone is watching you from across the room. A pair of eyes that, although tiny, seem to examine you in great depth, assessing you, processing information. There is a ruffling of feathers; the neck of this creature becomes inflated as his feathers stand on end. He starts bobbing his head up and down, like a dance. We’re used to animals communicating with us in this way: examining, displaying, perhaps threatening, or at least asserting themselves in our presence. But then the bird opens his mouth:

‘You be good, I love you. See you tomorrow.’

What has just happened here? Was this a clever trick of mimicry, whereby the bird can impersonate the sounds of speech but has no understanding of the meaning? Or is this not just mimicry but actual communication, with an understanding of what is being said? If so, then we have hit upon something fundamental shared between humans and animals – something that tells us about what language is, and where it comes from. In fact, these were the famous last words of Alex the parrot, about whom we will hear much more in this chapter.

Who are parrots?

Parrots of all kinds play a crucial role in our story. When we think of which animals are ‘like humans’, parrots spring to mind, as well as chimps and dolphins. And yet they are so utterly different from us. Different in the way they live their lives, in the way they perceive the world (for one, that they look down on us from above in the wild), and even in their size. How could something so much smaller than a human, with such a tiny brain, possess the kinds of intelligent ability – the ability to manipulate objects, create tools, solve puzzles, even, perhaps, talk – that we pride ourselves in holding so uniquely? Why does this bird, particularly, deserve a place in the parade of mammals that occupy the other chapters of this book?

Mammals seem to have cornered the market on intelligence in the popular imagination, but here is an exception. When we think of intelligent birds, parrots, together with crows and their relatives, are the prime candidates. Crows are indeed impressive problem solvers and tool builders. In Aesop’s fable, a crow, unable to get to the water in a pitcher, placed stones inside until the water level was raised high enough to reach. Crows actually do this, as well as shaping tools for extracting insects from logs, and even displaying a peculiar understanding of the laws of nature – they will stare perplexed at a picture of an object hanging in mid air, much longer than at a picture of an object sitting on a table. But the parrot is an animal that is not just as intelligent as a crow, or as many mammals, but is also highly communicative. Parrots seem to have followed an evolutionary trajectory tying together intelligence and communication, similar to that of our own ancestors.

Yet most people know parrots only through their cage-bound representatives. Able to copy our words (often, swear words to offend visiting relatives), friendly enough to ride on our shoulders (or on the shoulders of cooperative pirates), and long-lived, they certainly seem to exude an aura of internal untapped ability. But we rarely see them as fully fledged creatures of cunning, with their own internal mental lives, assessing the outside world and planning their actions to best effect. Most importantly, we rarely see them in groups. A solitary captive parakeet, no matter how well treated and well entertained, will never display its full range of abilities, but in the wild will leverage those abilities to cope with the world’s challenges. Crucially, a solitary bird can never display just how it uses those same remarkable and entertaining vocal tricks to survive in the wild, helping it to find and access food, evade predators, and raise offspring who must also grow up to learn all the tricks of being a successful parrot – including how to communicate with other parrots.

Strangely, even scientists know remarkably little about why parrots are as smart as they are. Just how they developed to be the interlocutors of the bird world remains an evolutionary mystery. Some general statements serve as a starting point. In the wild, parrots must live in groups to survive – often groups consisting of hundreds of individuals – and, of course, group living fosters complex communication. Their chosen food is diverse but rare – different kinds of fruit, nuts, and seeds that could ripen at unexpected and unsynchronized times. In general, plants have evolved to encourage animals to swallow their seeds whole, and poop them out somewhere far away to germinate and grow there. Parrots, however, are interested in breaking open seeds and devouring their nutritious contents – something that is against the plant’s interests. Therefore, seeds and nuts are often filled with toxins (whose concentration varies as the seed matures), or covered with a hard shell, to discourage exactly what the parrots are doing. So a parrot’s food, or similar-looking food items, may be toxic, or toxic if eaten at the wrong time, or may require some complex tricks to access the edible parts, which means parrots need to learn and remember foraging techniques. Parrots are not unusual in facing these kinds of challenges, but they have evolved to solve their problems in particular ways that support a level of complex communication unheard of among other birds. And a communication that to some extent parallels the communicative developments in those mammals that laid the foundation for our own language. Parrots are another key to how and why language evolved.

Alex the parrot: the world’s most talking animal

Alex the African grey parrot was something of a sensation in the bird world – in fact, a sensation in the world of animal behaviour in general. During his time working in Professor Irene Pepperberg’s lab in the 1990s and 2000s, he not only learned to speak human words, but he also appeared to develop a subtle and language-like understanding of how words are used, how they are combined, and what the different combinations mean.1 In other words, he learned to talk.

It remains perplexing that, in all the years that scientists have studied animal communication, the one individual animal that came closest to holding a direct conversation with a human was not a chimpanzee or a dolphin but a bird. What is it about parrots (or in particular about Alex’s species, the African grey parrot; or perhaps about Alex the individual) that has enabled them to use linguistic constructions far beyond the abilities of any other species that we know?

African greys are medium-sized, long-lived parrots – up to sixty years in captivity, although even in the wild they can live to be around twenty-five. They have become endangered in the wild because of the high demand for these impressive animals as pets – their uncanny ability to mimic human speech makes them popular, and so poachers can make a large profit capturing them for the pet trade. Most of the time, the parrots merely mimic. That’s a very long way from Alex’s purported ability both to use and to understand words. But it’s an important point. The ability to copy sounds in their environment appears to be common to all African greys in the wild. Unfortunately, the natural environment of the African grey is remote and challenging. Few scientists have spent enough time penetrating the thick jungle of central Africa to study these birds in the wild in any detail.2 So our understanding of why this species has evolved its remarkable mimicking ability – and, indeed, its ability to go beyond mere mimicry – remains tentative. But something happened in this evolutionary group of birds that laid the basis for an understanding of words and their combinations. Something about their environment – physical, biological, or social – set the stage for something close to language, and if we’re going to understand how our own language evolved, we first have to understand the parrots.

So how can we know for sure that Alex really understood what he was saying, when he said ‘See you tomorrow’, and that he wasn’t just cleverly copying words he had heard humans say? The claim that a bird could use words not just as sounds, but in the way that words are meant to be used – as words – is a remarkable claim. Alex’s behaviour in experiments shows us how we can know. For example, if presented with a tray with various objects of different colours, shapes, and materials, he could be asked questions like, ‘How many red squares?’ or ‘How many red?’ or even, ‘How many wood?’ To which he would answer, ‘Two!’, or however many of those objects were there. Guessing could never achieve good results in that situation. Alex also used words in a way that seems to us obvious yet is not seen in any other species: he could request items using their names: ‘Want banana’ (and would throw a tantrum if given something other than a banana). These observations are all strong indications that Alex learned not only the associations of the words but also their meanings. Most mysteriously, when confronted with a mirror, he asked Irene the question that she had so often asked him, ‘What colour?’ And that was how Alex the parrot learned the colour ‘grey’. This has been described as the only instance of a non-human asking a direct question.

Why could Alex the grey parrot do all these things? Why would any animal possess such abilities? The question is deep and intriguing. After all, parrots don’t speak English in the wild – why would a parrot evolve to have this ability, if there’s no one with whom to converse? The answer, as Irene Pepperberg puts it, is that her experiments ‘stress the avian system’ – they show us the limit of what these animals can do, even if the animals don’t actually push that limit in their day-to-day lives. That, in itself, shouldn’t surprise a biologist. Not everything that evolves in nature is used for some adaptive purpose. Sometimes (like the very feathers covering our parrots) a feature evolves for one purpose (in the case of feathers, to keep certain dinosaurs warm), but carry within them the possibilities of evolving to serve another purpose (flight). So even if animals don’t actually talk, the mere fact that an animal could display clear language-like behaviours must be a crucial piece of evidence in our search for the nature of language itself, where it comes from, and how much ‘languageness’ other species have. At the very least, we can say that somewhere, deep inside at least one African grey parrot, was the core of what is necessary for language. Probably that’s an understatement. Alex may have been exceptional, but he was unlikely to have been a super-parrot. Most likely his fundamental capabilities are shared by others of his species.

The difference between copying and understanding

The truly exceptional feature of Alex’s communication is that he appeared to learn to refer to things – and not just by some arbitrary label, or unique sound that was simply associated with the object. Scientists make a huge distinction between these two seemingly similar ideas, and with good reason. It’s likely that the ability to refer, rather than just associate, lies at the heart of those cognitive skills that give us our language ability. In essence, the big distinction is between some unconscious automatic reaction and a mental concept that goes with the ability to abstract an object. When you show a baby a picture of a dog and say, ‘Doggy!’ they will initially form a simple association of the sound with that specific picture. But very soon children learn that this label refers to all dogs, living creatures as well as pictures, and also to the concept of dog, rather than to a specific individual animal. It is an understanding of that abstract meaning of a label that is so rare in other species.

Imagine a rat in a cage that contains a blue button and a red button. Every time the rat presses the blue button, food is dispensed automatically; but when the red button is pressed, nothing happens. It won’t take long for the rat to learn that pressing the blue button means that food arrives. This kind of experiment was historically the core of animal behaviour research, and although today examining animal behaviour is often carried out in more naturalistic environments, such operant conditioning, as it is known, is often thought of as illustrating the limit of animal learning. Animals can learn to associate some stimulus with some outcome, but this is learning by rote: they do not need to understand that connection. After all, it’s possible to teach all manner of creatures, from snails to goldfish, to associate a stimulus with an outcome. We don’t believe that the simplest of animals has a true mental understanding of the relationship between a blue button and the delivery of food.

But we humans do something more than that. We have an understanding, rather than just an automatic association. Consider yourself in that same cage. You too will learn quickly to press the blue button to get food. How are your thought processes different from that of the rat – if at all? It seems instinctively obvious that they are different, although it’s difficult to pinpoint why. You have some kind of idea that blue means food – something beyond the mere association between colour and outcome. If I were to ask you, ‘What does blue mean to you?’ you would doubtless say, ‘It means dinner time.’ We call this ‘reference’: blue refers to food, because it is a kind of internal mental concept – a state of mind that we can feel and express and that we believe exists in the minds of other humans as well (although, of course, we can never be completely sure of that). There is a feeling that we are conscious of possessing, rather than a ‘if this, then that’ response. In the same way that we (may or may not) associate blue with picnics and sunny days, or with the ocean and tranquillity, the stimulus of the colour blue evokes a cascade of internal mental states – more mental processing than we think exists in something like a snail. What’s more, we understand that if blue refers to food, then we can use that same label ‘blue’ to communicate about food to others – to ask for or to offer them food. This is why reference lies absolutely at the heart of an understanding of language ability. But do we know for sure that the rat does not have a similar kind of concept? Can we be sure that rats merely respond to a stimulus associated with food, rather than thinking that the stimulus refers to food? Well, that’s tricky. It’s hard to prove that the rat doesn’t have such a concept of reference, because the obvious way to find out is simply to ask the rat. If we want to know whether a human has an internal mental concept of something, then we just ask them – but of course, animals don’t speak …

We can get a handle on this by reversing the question of whether or not animals have reference. If they did, what would we expect the outcome to be? Most scientists feel that reference is absolutely crucial for language. After all, language (as we know it, i.e. human language) deals an awful lot with abstract concepts. I can talk about imaginary creatures like unicorns and hippogriffs. I can talk about imaginary situations such as what I would do if I won the lottery. I can also talk about simple and concrete concepts that don’t happen to be concrete at the moment – the keys I left in a drawer, for example. Probably, reference and abstract thought go hand in hand. The keys aren’t here, but my words (and thoughts) refer to them all the same. So, it might be reasonable to argue that if an animal could use these kinds of abstract linguistic constructions, then it makes sense that they must have an underlying referential ability. A certain kind of language use would be a good indicator of what’s actually going on in the mind of the animal. If an individual animal could talk about colours in an abstract way, we can suggest (not prove – we can never prove what another individual is thinking) that they also have a referential understanding of the colour of the food button. They’re not just responding automatically like a sponge or a jellyfish would respond to movements in the water nearby – moving towards food or firing a stinging spine. And if it were the case that an animal could use abstract linguistic constructions, then that would imply that such an animal has the underlying cognitive structure that supports some of the key features of language. They would have at the very least the evolutionary foundations of a language ability. So, what do we find? Can Alex the parrot help us answer some of these questions?

Some clever experiments are required here. If I were to present an animal with a tray of differently coloured objects, ask, ‘Which is blue?’ and he were to choose a blue object, you would be rightly impressed. This animal has ‘understood’ your instruction, and clearly has recognized what is blue and what isn’t. But has he understood what blue is? That’s a little less convincing. Perhaps when hearing the sound ‘blue’, he automatically selects an object that has a particular colour, merely associating the sound with the visual stimulus. Associating a stimulus (e.g. a colour) with a particular response is something we can see right across the animal world. A fly launches itself into the air when the swat approaches it. Even plants grow towards light (although we don’t usually consider that plants ‘think’ per se). You could imagine the evolutionary benefit of the ability to make these associations, particularly if good food is associated with different colours, and other flock members are sharing information about what food is around. I squawk the parrot equivalent of ‘blue!’ and all my family realize the blue berries are ripe. But that’s not necessarily understanding colour. That’s not reference. Parrots might do more than respond automatically when hearing ‘blue!’ How might we test? One of the great innovations that Irene Pepperberg made was to design experiments that could bypass this seemingly unsurmountable barrier – how to see into an animal’s mind and distinguish thought from conditioning? (Although, of course, notwithstanding Irene’s skill, none of this would have been possible without Alex’s ability.) The leap she made was to ask a completely different kind of question. Presented with two objects, say a blue triangle and a red triangle, or perhaps a blue triangle and a blue square, Alex would be asked, ‘What’s different?’ We know that the answer in the first case is: ‘Colour. The colour is different,’ and the answer in the second case is ‘They are different shapes.’ Notice that this is simply not a question that can be answered by association. Unless the animal learned by heart every combination of two objects of different colours and shapes, and the associated correct answer, the only way to get this right is to understand that ‘colour’ is an abstract concept that is different from another abstract concept ‘shape’.

And Alex could do this. In fact, he was remarkably good at it.3 Alex could distinguish when objects differed by colour, as opposed to shape, or even the material of which they were made, and he would give his answers in speech – by using words like ‘colour’ and ‘shape’ to indicate where the abstract differences between groups lay. There seems little doubt that Alex as an individual, if not all grey parrots, possessed that fundamental requirement and foundation stone of language: the concept of reference. But why on earth should a small bird be so linguistically competent? And although, when pushed, Alex the parrot could show impressive linguistic abilities, why aren’t all grey parrots in the wild chatting away in their own language? In other words, why do parrots have this ability, and why hasn’t it evolved into true language?

The sounds parrots make

Although the intimate lives of grey parrots in the wild are largely hidden to us by the harsh environment that they call home, these amiable birds rather thrive in captivity and, if kept in large enough aviaries with a large enough number of flock-mates, can live lives that at least to some extent mirror their wild behaviour. I’m lucky enough to be working with some of the biggest African grey parrot communities in captivity, at the Loro Parque zoo in Tenerife. Here, Sara Torres Ortiz and other scientists are studying the way that parrots learn – not just African greys, but also red-fronted parakeets, blue-yellow macaws, and the massive and raucous great green macaw. The lab offices, fronting onto the aviaries, are overwhelmed by a deafening stream of screeches and screams – lab members wander around blissfully wearing noise-cancelling headphones. Among these loud and angry parrots – mostly, they resent humans walking around in their cages – the African greys sit quietly, observing everyone and choosing their comments carefully. Greys are the most important subject of the learning experiments, and the most intriguing. Placed in front of a box containing different shaped objects, as Alex was, they are trained to choose which shape matches the one shown to them by the trainer. Whatever variation of colour, shape, and material is used, they quickly learn what is required, and match the correct object to the one shown by the trainer. ‘Thoughtful’ might seem an unnecessarily anthropomorphic description of these animals, but it is a description that fits. Whereas macaws scream and fly up into the branches when you approach their aviary, the greys come to the front of the cage and tilt their heads this way and that, sometimes turning their necks horizontally to get a better view of you from all angles. ‘What is this new development?’ they seem to ask. So compelling is this vague impression of intelligence lurking behind their beady little eyes, one can’t help wondering, do these animals talk to each other? What do they talk about? Why do they talk at all? What benefit does it bring them?

23. Being examined by African grey parrots in the lab.

Sitting down quietly and observing a flock of grey parrots for a while, something quickly becomes obvious: this is a pretty laid-back community of birds. If you’ve ever watched the small garden birds at your feeder, they are constantly in motion, continually displacing one another. One perches on a branch, and another comes to land on the same branch, chasing the first bird away. Such displacements are a key part of bird social behaviour, and scientists use displacement behaviour to measure the dominance relationships between the individuals. A dominant animal will constantly be chasing others away from their perches – that’s how they establish their superior position. But grey parrots take life a little easier. A bird landing on the same branch evokes an interested turn of the head, rather like my arrival at the lab aviary, but not an immediate flight. Of course, it’s not all love and peace in the parrot world – sometimes the newcomer will take things a little further, even shuffling sideways bit by bit until they push the resident right off the branch. But dominance relationships don’t seem to be established in the usual rush of chases and lunges that we see in other species. When feeding, one bird chewing on a grape, for instance, will often be approached by another who gently nibbles at the first bird’s beak, carefully sampling some of the grape for themselves. Such interactions in animals are uncommon outside of a mating pair – uncommon, but not unheard of. Chimpanzees will gesture to others in a request for some food to share, and wolf cubs will lick the jaws of an adult to encourage them to regurgitate. Hopefully the connection between these very different species is not lost on the reader: a stable, complex social structure, serving some purpose for all the animals involved, works best when conflict is at a minimum. Something is keeping the wheels of society turning smoothly. And that something must be a form of communication.

The second thing to notice about African greys is that they have two different kinds of sounds: squawks and whistles. The first, the squawk, is a classic parrot noise. True, the greys don’t use their squawk with quite as much enthusiasm as the parakeets and macaws in nearby aviaries, but it’s a unique sound, and one that’s unmistakably associated with parrot communication. Parrots squawk for warning, in distress, or just to draw the attention of others to something of interest in the environment. A squawk is a loud, harsh sound. Unlike the spectrograms we’ve seen so far, squawks don’t contain a single frequency, like one note on a piano. Instead, imagine a child smashing down on as many piano keys as possible at the same time. These kinds of sounds grab your attention quickly – they don’t contain much information except ‘hey!’

Everyone’s familiar with a parrot squawk – it’s the ‘aargh!’ that precedes a declaration like ‘Pieces of eight!’ or ‘Polly wants a cracker!’ Squawks can be fairly complex – we think that at least some parrots can identify which individual is squawking from subtle differences in the sound. But it’s nonetheless a blunt instrument. What impresses us most with a parrot’s vocal ability – and what is important for our journey today – is their ability to mimic a wide range of other types of sounds. We’ve seen how Alex could copy the words that Irene and her team were using, and the newspapers are quick to jump on stories of parrots being removed from display at zoos because visitors have taught them a range of swear words. Where does this uncanny ability to mimic sounds come from? Why do they do it? Only by watching the interactions between parrots in something like their natural environment can we glean any clues.

24. A spectrogram of a parrot squawk, immediately followed by a parrot whistle. The squawk contains many frequencies at the same time, whereas the whistle here is a simple up-down note.

Our colony of African greys are vocalizing all the time, regular squawks, and the occasional whistle. The squawks could well be a kind of contact call – just a message to say, ‘I’m here, everything’s OK.’ A forest full of squawking parrots is a very noisy place, and squawks aren’t a good way to transmit information in that noise. As we’ve seen in other chapters, tonal sounds – whistles – cut through the noise, can be heard at long distances, and can contain a lot of information. So those whistles are a good candidate for a vocalization that is interesting. But the behaviour that parrots use when making whistles has a very different pattern as well. Typically, one bird will sit on a branch, whistling every so often, mostly using the same whistle over and over, like a favourite tune you might have a habit of humming. We then started to name the different parrots by their typical whistle: this one is ‘Uh-Oh’, whereas that one is ‘Woohoo’. Although this might seem to be similar to the dolphin signature whistles we talked about in the last chapter, it doesn’t seem that individual parrots actually have exclusive whistles. Rather, a particular whistle seems to take their fancy for a while, and becomes a kind of earworm, then being exchanged for another when they get bored.

25. A spectrogram of fifteen seconds of calling by African grey parrots. Plenty of squawks, but the occasional whistle as well.

But even if whistles aren’t names per se, they can still convey useful messages. Whistles are complex sounds, possibly harder to produce than squawks, and certainly harder to produce regularly and reliably, almost exactly the same each time. So, these whistles can act as a kind of signal, an advertisement of how sophisticated a particular animal is, both cognitively and physically. The more impressively complex and regular are your whistles, the more attractive an individual you are. Such signals could easily be part of the mechanism for establishing dominance, in parrots, or in any other species.

African greys, though, also copy each other’s whistles. That in itself is not surprising: many species of songbird learn to sing by listening to the males singing around them, and picking up their tunes, albeit with some modification. In most songbirds, however, once a song is learned, it’s fixed for life. They don’t generally copy different individuals with different songs each time. So, the kind of mimicry that parrots can do is already unusual. Where song copying does occur in other avian species, it’s usually an aggressive signal. It’s not unknown for one bird to turn and attack another violently for copying his song. So, on the face of it, it’s not surprising that, in the play for dominance, parrots too should mimic each other. But African greys go a step further. While one bird (let’s say ‘Uh-Oh’) is busy whistling, another might start not only copying that whistle, but also embellishing it. As if to say, ‘Well, that’s a fancy sound you can make, but just listen to this!’ There’s a very big difference between mimicking, simply to copy another animal, and modifying, embellishing, and improving on a sound. The Australian lyrebird is a rather unremarkable-looking creature, except for the male’s ludicrously long tail, and his even more ludicrous ability to make impressive songs by combining excellent copies of the sounds he hears around him: including those made not just by other animals, but also by things such as chainsaws, car alarms, and camera shutters. No one can fail to be impressed by the fidelity of his vocal rendition. But combining many different sounds into a new composition (a remix) is a relatively simple task, and not quite the same as altering the elements themselves, changing the actual tune, which would seem to imply some substantially more sophisticated mental processing.

26. Two whistles made by two different grey parrots, the second copying the first, but adding an embellishment, an additional whistle, at the start.

So, picture the situation: one parrot is sitting on his branch whistling, ‘Uh-oh’, ‘Uh-oh’, over and over again. Another bird turns towards him and whistles, ‘Ooooh, Uh-oh’. If we were to think of our own emotional responses in such a situation, we might feel humiliated. We’ve been outdone. And this might indeed be precisely the role of such an interaction – establishing dominance by outperforming your rivals in a vocal challenge. A kind of avian duelling banjos. In this case, I am speculating somewhat, as no one has studied the dominance interactions between these birds in any detail, but as a working hypothesis, it is consistent with what we know about grey parrot behaviour.

One more anecdote helps to complete the picture of the role of both producing and understanding such complex calls. While sitting in the lab aviary, one parrot (‘Wolf-whistle’) was busy producing her impressive sounds over and over again. No one was mimicking or embellishing. But two of the birds were particularly interested in my colleague and me, sitting opposite the birds at the other end of the aviary. Climbing on the bars of the cage, they tilted their heads and poked their bills through the gaps, trying to find out more about us. And then, very softly, we could hear them: mimicking Wolf-whistle under their breaths. Were they merely being cautious, not wanting Wolf-whistle to hear them, as it might be interpreted as a challenge to a possibly larger and stronger bird? Or was the instinctive drive to mimic so strong, that the parrots just had to respond, even if only to themselves?

Suddenly, viewing the complex vocal communication of parrots takes on a different perspective: animals using their mimicking, embellishing ability, to perform a clear social function. If your social standing depends on your ability to copy others, and to embellish their sounds innovatively, then the evolutionary pathway to more and more complex communication is no longer as mysterious a road as it once seemed. We can see a driver, an evolutionary force, favouring more sophistication, more complexity, for a clear benefit to the individual. This is the most fundamental requirement of any evolutionary theory: a new trait must provide a benefit to the individual’s ability to live, produce offspring, and raise those offspring to be successful – only that way does a trait persist and spread through the generations. And as we still want to crack the mystery of how language could have evolved, step by step, our grey parrots could be slipping another piece of the puzzle into place.

Learning by interacting: building understanding

The social interactions between vocalizing parrots also helps us answer another mysterious question: why was Alex unique? Why can’t chimps and dolphins and dogs be taught to do the same? Here, the answer is both evolutionary and methodological. For decades (actually, probably millennia), people have been training animals to do their bidding using techniques of conditioning. Modern animal trainers have a sophisticated system that initially involves rewarding an animal for performing the desired action accidentally: say, jumping through a hoop, or presenting a paw for having its claws cut. Over time, the animal associates a particular behaviour with a reward, and will do what’s wanted on request. This is a very straightforward operation (although frustratingly difficult to achieve with your own dog, when he doesn’t like having his claws cut), and can be used even on animals as simple as insects. As a result, people have tried to train animals to talk using the same method. Show a gorilla a banana, and if they make the sign-language symbol for ‘banana’, they are rewarded.

Alex was trained using a completely different method. Irene realized that, in the wild, there’s no ‘trainer’. Parrots learn from each other in a very spontaneous and undirected way, just by observation. So, she made use of a method initially developed by psychologist Dietmar Todt in the 1970s called the model-rival (M/R) technique. Despite the fancy name, anyone with kids is familiar with this method. Little Ellie doesn’t want to eat broccoli. I take some broccoli and show it to my accomplice, Ellie’s older sister Maayan. ‘Would you like some broccoli, Maayan? Say “please”.’ Maayan says, ‘Please may I have some broccoli, Daddy?’ and all the while, Ellie is watching carefully. She is at the same time competing for my attention, and she understands how to gain that attention. Soon she will say ‘Broccoli!’ but I make it clear, using her sister as a demonstrator, that you only get the broccoli if you ask correctly: ‘Please may I have some broccoli?’ Notice the difference between this approach and more traditional conditioning. If you teach your dog to ‘sit’ by providing a treat when she sits, there has to be (at least initially) a very strong correlation between ‘sitting’ and ‘getting a treat’. If the sitting weren’t reliably rewarded, the training would fail. It’s that reliable association that makes conditioning so successful with such a wide range of species of different levels of cognitive sophistication.

The M/R method is much harder for animals to understand. There isn’t a clear association between a stimulus and a reward. The animal must understand the interaction that is taking place between the model and the rival. But of course, social animals do tend to understand social interactions. What’s astounding about the M/R method is that it translates so naturally to the wild behaviour we expect from animals. Earlier I described two parrots sharing a grape. Imagine two such birds (perhaps a mated pair) standing on a branch with one enjoying a grape and the other nibbling at her beak, begging for a taste, which she happily allows. Now consider a third bird observing them. Simply by observation, he can learn the signals necessary to beg for food, and so a clear evolutionary advantage exists. Of course, at first the animal is learning nothing more than associations, but as the stimuli become more varied, the only way to continue to get the reward is to broaden your understanding of the social interactions taking place. That means broadening your understanding of a concept such as ‘broccoli’, or ‘blue’, and – if your brain is built for it – to understand abstract concepts like colour or shape.

27. A conversation between two researchers as part of the M/R training technique, with Alex the parrot observing the interactions.

The M/R technique is astoundingly effective with grey parrots, probably because it so neatly matches the way they learn in the wild. But it has rarely been used with other animals. Even with parrots, this is an exceptionally time-consuming methodology. It can take months or years for an animal to develop an understanding of the task – not necessarily surprising when these birds live for many decades in the wild and have an extended childhood lasting for years. Even after maturing, parrots can take many years of learning good parenthood before they successfully raise chicks. But in the lab, spending years sitting with a bird is a slow research trajectory. On top of that, it’s one thing to sit across a table being patiently observed by a small grey bird. It’s quite another thing to induce a dolphin or chimpanzee to give you their full attention for long periods of time, in an environment that they may not find natural and relaxing. So it may be that many other species are capable of true referential comprehension – but we just haven’t got round to finding a way to test them.

Social parrots in the wild – a hectic and chaotic community

I’ve said all along that social skills and communicative skills are both important in the evolution of language. Complex communication exists precisely because social interactions are complex. We observe that parrots have complex communicative abilities, and presumably that reflects the complex social environment in which they live. What’s more, the success of the M/R method – a fundamentally social way of learning – gives us a clue that this kind of interaction might have some parallels in their natural behaviour in the wild. But just how social are parrots in their natural environment? Why do such social skills, like learning from the interactions between others, exist? And how – if at all – do wild parrots use their social skills in practice? Are they really ‘like us’: feathery humans with complex relationships, complex goals, and complex intentions? Almost certainly not. The needs of animals living in the wild are likely to be very different from those needs with which our proto-human ancestors were faced. Many benefits of social living are clearly common to different species, but each species has its own particular needs, and its own particular solutions.

Living in a social group allows animals to exploit a difficult environment, one where a group could survive, but an individual would fail. And many parrot species do live in large groups – tens if not hundreds of animals can be seen roosting and feeding together. But parrot flocks aren’t societies as we understand them from our human experience. Nor are they like chimpanzee troops or wolf packs. The interactions between individual parrots are more tenuous, more incidental. The fundamental unit of a parrot’s relationships is the pair-bond: the partnership between a male bird and a female bird, with the aim of raising chicks (usually, but not always – there are plenty of examples of same-sex relationships in birds, which just demonstrates how powerful is the social need for companionship). Outside of that close relationship, the rest of the flock seem to be mostly just considered ‘others’. In fact, parrots probably have individuals they like more, and individuals they like less, but none attracts as much attention as a parrot’s mate. The amount of time that two paired birds spend together, preening each other, caring for young, or just hanging out together, is the large bulk of a parrot’s social-time budget. But this raises a perplexing question. If birds are fundamentally living in pairs, mostly interacting just with their partner, then in what sense do they live in a complex society? If, as I am claiming, the complexity of parrot cognition arises largely from the complexity of their social groups, how complex can your social group be if you spend most of your time only with your partner?

Flocks of parrots gain the advantage of numbers in many different ways. A large flock, feeding together out in the open, is much more likely to spot a predator than a single bird feeding on its own. Many eyes increase the likelihood that someone will spot a threat, even if just by chance. But living in a group isn’t all roses. Ordinarily there are costs to being social – for example, any food you find needs to be shared between everyone. You can imagine that a flock of a hundred parrots, squabbling over limited food, could get really nasty. Animals moderate these dangers in different ways. If you live in a small group, like a wolf pack, then a dominance hierarchy can develop. Some animals higher up in the dominance hierarchy have first access to resources: food, mates, sleeping spots – anything that gives them better reproductive success. Other animals, lower down in the hierarchy, know that there’s no benefit to fighting the big boss, and so they eke out what living they can. In that way, even if there are only limited resources, animals won’t be wasting their time constantly squabbling. Natural selection has a tendency to even things out in that way. But in a flock of a hundred parrots, even the bossiest bird could not possibly keep all the food to itself. So, these very large foraging flocks tend to occur when food is abundant, and its availability unpredictable. In the tropical forest, where fruit could become ripe at any time of year, animals always must search for today’s feeding opportunity: which tree has the ripe fruit today? Again, many eyes make light work – the animals share information on where the good pickings are now, and in return they receive the protection of the flock when feeding. As there is often more than enough food on a single tree for everyone, it looks like a win–win situation. Large, loosely associated flocks suit that jungle fruit-and-nut-eating niche well, and this is the niche that parrots have evolved to exploit. And for this, rather simplistic form of sociality, it isn’t necessary that you know your neighbour particularly well. The anonymous crowd is good enough for finding food and protecting from predators.

I’ve also spent time observing the social behaviour of one of the best-known social parrots: the monk parakeet. Monks (also known as Quaker parrots) are attractive small birds: bright green with a white chest, they make popular pets. They bond well with humans, are vocal, but not too noisy, and their acrobatic antics in a cage, using their beak as a third leg, makes them amusing subjects to observe, even in captivity. But monk parakeets in the wild are simply spectacular. They are one of the few parrot species that build their own nests – and what nests! Huge colonies many metres across, with nest cavities housing tens of breeding pairs, like small apartments in a giant building. Apartment living – for anyone who has never tried it – is a complex game. Your neighbours may be too loud, their kids make a mess or bully your kids, they may even steal from you (and so far, I’m only talking about the parakeets). Clearly, a lot of social skills are needed here, and so monk parakeets are a good place to start when searching for the social origins of communication in parrots.

Nest building is unusual in parrots because they are mostly tropical species, living in an environment where holes in rotting trees provide ample protected space to incubate eggs and raise young. But monks are native to the grasslands of South America, and there, ready-made cavities are hard to find. Instead, the parrots have a prodigious stick-gathering obsession, and direct this towards building towering monstrosities of somewhat carelessly woven stick-nests, which adorn any appropriate raised surface. Whereas in their native range, the stunted trees of the Pampas were their natural foundation, monk parakeets have spread across the world, largely as the result of the pet trade. They dismantle electricity transformers in the USA and overrun ornately crenellated architecture in Barcelona.

Breeding pairs of monks are thrown together in this apartment living, presumably because a single nest of twigs would be too flimsy and offer too little protection. Instead, each pair builds its own cavity, sharing a larger superstructure with its neighbours. But there are no interconnecting passages, no shared facilities; just multiple nests, each with its single entrance, and dividing walls between each family unit. This is not true cooperation, in the way that a group of humans would cooperate to hunt a mammoth or build a space shuttle. Monks don’t cooperate to build a structure that is particularly stable (catastrophically, these massive nests often fall to the ground), and indeed, a parakeet is not averse to sneakily stealing sticks from a neighbour’s nest when no one is looking. In fact, when you watch parakeets building their nests, carefully trimming a twig to the right shape and length, then threading through the existing twigs to give support, it’s noticeable that even mated pairs don’t particularly cooperate in the construction. Two birds can be working on the same nest, more getting in each other’s way than helping. They’re skilful weavers, but it’s all pretty haphazard, and I for one can’t detect any coordination between individuals. Sometimes when one spouse gets in the way of the work of another – perhaps he’s pulling on a twig that she just put into place – it can result in a lot of frustrated head-bobbing and apologetic mutual preening. But there’s no doubt these animals are not communicating to each other what task needs to be done. They have that communicative ability, but they’re not using it.

28. Multi-family apartments: the communal nest superstructure of monk parakeets.

So, what is going on here? I’ve said that parrots are an important key to understanding the evolution of communication and language. But why don’t the parakeets use it? Why put up with interfering neighbours and spouses, and poorly constructed nests that regularly collapse, when you have the capacity – presumably – to negotiate your way to a better, more cooperative, and more effective way of living? For that matter, why don’t lions, wolves, and monkeys – all animals, in fact – cooperate better, using language or something like language to communicate their plans, intentions, and desires?

29. Some examples of monk parakeet vocalizations in different circumstances.

Parakeets definitely have a very wide range of vocalizations, and different vocal behaviour certainly expresses different emotions and different intentions. But to a large extent, this is a by-product of their learning flexibility. The mere fact that parrots can leap and bound forward cognitively and expressively as Alex did, taking advantage of the power of the M/R method, shows that this is a natural ability of parrots in the wild. A young parakeet, watching his parents weaving sticks to strengthen the nest, learns to do the same – not through conditioning, whereby a particular outcome is rewarded, and a different outcome is punished. In fact, it would appear to be impossible, or at least very difficult, to learn to build a nest from conditioning. Trial and error is a slow process when the error involves falling ten metres to the ground in a tangle of sticks. No, the kind of cognitive skills that a young parakeet needs if it is to learn how to build a nest for itself, assert itself in the face of stick-pilfering neighbours, and form a close bond with a mate, are skills of mimicry. Mimicry for attention – the very essence of M/R. Scientists did not ‘invent’ a particular psychological training method, rather, they tapped into a very fundamental aspect of parrot behaviour. Mimicry, reference, perspective taking: these complex cognitive skills are essential to learning to be a successful parrot, and so it is no wonder that some species of parrots are excellent mimics when it comes to language too. Perhaps that also means that they can learn to speak to humans, as Alex did. This is another example of evolution providing animals with building blocks, useful for one goal, but which can be adapted for even greater achievements.

So, are parrots just a weird outlier, a strange animal, very different from us, who just happen to talk a little bit like us, but only by coincidence? Or are they indicative of some common mechanisms, some common evolutionary pathways, shared both by ourselves, with our complex language, and by the likes of Alex, who could count to eight, and parakeets who struggle to agree where to put a stick? I’ve said that parrots are special, and even if you accept Alex’s achievements as being true language, you might wonder why he stands as the sole clear example of a talking animal, and why parakeets seem really rather dumb in comparison. But parrots are special, not so much because of how well they can talk (they can’t much, in general), but because of how they illuminate the evolutionary forces that are acting on communication – the same forces that pushed our ancestors to develop a true language.

Parrots really fit into our story in two ways. They show us that there are multiple evolutionary tracks that can lead to a language ability. And they show us that the brains that are needed to form a language exist for reasons other than language – and they can be co-opted into linguistic adventures as and when needed. It’s worth contrasting parrots to some of the other species we’ve encountered. Wolves live in tight-knit groups and depend on each other in a truly cooperative way, and, hauntingly beautiful as their communication is, they probably have the capacity to convey only a limited number of concepts. Dolphins, in contrast, appear to be capable of expressing quite complex concepts in their day-to-day lives. Parrots are in neither of these groups. They seem to be expressive, and attentive to the sounds that others make too. But, like wolves, they probably don’t say very much. They don’t need to. The concepts they need to convey – friendship, annoyance, warning, excitement – can easily be encapsulated in the repertoire that they have. In fact, that repertoire is huge – far larger than is needed to say what they need to say. It is so large at least in part because of their mimicry, and their mimicry probably evolved for reasons other than expanding their repertoire. That in itself is not unusual in the animal world – many songbirds have ridiculously large vocal repertoires for the simple messages they need to convey. No, the key difference with parrots is that, in addition to their vocal flexibility, they have the cognition needed to put one plus one together. They can solve problems and build structures, they can learn from each other how to crack open nuts, or which fruits are good to eat. They can stay out of the way of bullies, and still make use of the protection of the flock. They have that golden combination of complex social and learning needs and complex vocal abilities.

So, whether Alex was, in fact, unique in his abilities (and Irene Pepperberg is now getting similar results with another African grey parrot, Griffin), he was telling us something about what animals can do and why. Parrots, wolves, and dolphins have evolved for three completely different ecological niches. Parrots with pair-bonds in large groups; wolves in small but far-ranging family groups; dolphins in a fission-fusion society in a three-dimensional world. But all three seem to have hit upon similar solutions to some of the problems of group living: know who your neighbours are, tell them what you want, and know what they want of you. In some ways, it’s surprising that these abilities haven’t evolved more often. Of course, none of this is language. There is still a barrier to be crossed. The parrots in the cage are simply not saying very much to each other. But although the needs of parrots in the wild are complex by bird standards, they are childishly simple by human standards – parrots need to share information about food, and to form social bonds, but they don’t seem to develop specific careers, educate their offspring, and calculate taxes. Economy is greatly prized in evolution – complex abilities don’t evolve if they don’t give some concrete advantage. But simplicity and reusability are strongly favoured, if only because the role that chance plays in evolution means that, if something might perform a novel function, the likelihood is that at some point, it really will be able to perform that function. Flexibility seems to build – in some circumstances – latent capabilities that can be adapted later, and could, eventually, allow an animal to cross that threshold between non-language and language.

We tend to think of language as universally useful, but that’s a very biased perspective. We ourselves can’t imagine living without language, but animals, of course, can. Alex benefited from language because of the unique experimental environment he was placed in. But it’s very significant that before the experiments started, he was capable of benefiting from language. He had that built-in flexibility. Which species have that, and which species don’t? And how did our ancestors find themselves in an environment where they would benefit from language? Do other animals live a life that has some parallels with the lives of parrots? Just how widespread is this underlying potential for language? As we’ll see in the next chapter, perhaps very widespread indeed.

30.

4. Hyrax

Chances are you’ve never heard of a hyrax. Why should you have? The hyrax is an odd, obscure creature, looking something like a cross between a guinea pig and a rabbit. Common across the Middle East and eastern Africa, hyraxes are in fact not closely related to either guinea pigs (rodents) or rabbits (which are not even closely related to rodents either). A quick look at the hyrax’s paws shows one of the differences: stubby little fingers covered with rough pads, instead of claws. Together with their elongated tusk-like incisors, these features give a clue to the hyrax’s closer relative, the elephant.

Still, the ancestors of today’s hyraxes split away from the elephant lineage not long after the dinosaurs became extinct, and hyraxes are something of a modern anomaly. While not quite bizarre enough to be considered a ‘living fossil’, i.e. possessing ancient traits that have disappeared from all other animals, hyraxes retain some ancestral features that we don’t see in most mammals today. For instance, despite being warm-blooded like all mammals and birds, their ability to maintain a constant body temperature is limited. They must huddle together, and bask in the morning sun, in a manner more reminiscent of lizards than rabbits. Hyraxes also hold the honourable position of having given their name to an entire country. When Phoenician sailors arrived in the Spanish peninsula and saw the landscape overrun with true rabbits, they noticed the similarity with the hyraxes of their native lands and called this new country Ee-shafania, meaning ‘Island of the Hyraxes’ (hyrax is still ‘shafan’ in modern Hebrew). In due course, the Romans refined this name to Hispania, and thence Spain.

31. A pair of hyraxes, and a close up of their peculiar

32. Elephant-like feet

33. Tusk-like incisors.

These charming little creatures fit into our story partly because they are extremely vocal – their barking, grating songs ring out over the Middle Eastern hills, where they scamper across giant boulders. But that is not particularly unusual – many birds sing much more prominently than hyraxes do, and much more complicated songs too. No, what’s interesting about hyrax song is that it seems to have syntax, and most linguists think that syntax is an essential component of true language. When you combine a sequence of words to make a sentence, it’s those rules of how to order the words that really provide the potential for complex communication. What would language be if the order of words were irrelevant? Syntax – the word-ordering rules – underpins every language that we know of. And yet, hyrax songs have syntax too. Hyraxes order their sounds in special ways to make their songs sound right, rather like we make sure that what we say makes sense by putting our words in the right order. What’s more, unlike most songbirds, hyraxes seem to learn this syntax, and adapt the structure of their songs accordingly. If a syntax is necessary for a true language, a learned syntax is doubly so – human children could not possibly be born knowing precisely how to talk, they must learn to do so. As hyraxes do.

Why would these weird, tiny mammals have complex learned syntax in their vocalizations at all? Surely they don’t really have that much to say? Probably not. But the fact that syntax creeps into the vocalizations of so many animals, even the humble hyrax, points to just how ubiquitous syntax really is in the animal world. And if almost all animals have syntax, might some of them have language?

Meet the hyrax

I spent the four years of my PhD studying hyraxes, and these charismatic creatures have a nostalgic appeal to me. I say charismatic, but they are smelly, aggressive, and so covered in fleas and ticks that trapping, immobilizing, and placing radio collars on them is a decidedly unpleasant experience. But they are charismatic nonetheless. There is something primal about these animals, one of the three surviving species of a lineage that once included a giant grazing hyrax the size of a hippo. Another peculiar remnant that they retain (as do rabbits) is a relatively simple digestive system. When sweeping herds of grazing mammals exploded across the planet with their highly efficient multi-chambered stomachs that allowed them to digest tough grasses easily (driving giant hyraxes extinct), the remaining hyraxes and rabbits retained simpler systems. Whereas rabbits digest grass twice (reingesting partially digested droppings to give them a second chance to be broken down), hyraxes make a big deal of chewing their food carefully before swallowing it – giving them a behaviour that is superficially like the ruminating of cows. This excessive chewing of both hyraxes and rabbits is presumably the source of the perplexing passage in the Bible (Leviticus 11:5) in which both hyrax and hare are declared unclean because, although they ‘chew the cud’, they don’t have cloven hooves like cows and deer. Neither hyrax nor hare actually chew cud, in the sense of regurgitating stomach contents as cows do, but if they’re going to digest plentiful but tough food like grass, they need to invest in some extra processing.

Hyraxes are also extraordinarily social animals, and they have the appealing characteristic that their sociality and cooperation is openly displayed. You don’t need to look far to see hyraxes in their social groups – gatherings of tens of animals, each perched on a separate boulder like pieces on a giant chessboard. Hyraxes don’t actually cooperate to find food, or to build shelter, but group living serves them well. I’ve already mentioned how their imperfect control of their body temperature means that they must huddle together for warmth, particularly in the cold desert nights. But also, lacking any real defences, they are vulnerable to predators like jackals and eagles, so it makes sense to live in a group where many eyes are available to look out for danger.

In some ways, modern hyraxes are a useful window into the evolutionary origin of mammals, as they retain traits that have been brought forward from the days of the dinosaurs. True, they are adapted to today’s world, not to the wasteland that covered the Earth after the asteroid strike that wiped out three-quarters of the species on the planet. But among those ancient traits that hyraxes have retained, might their communication be one of them?

A song for showing off

Hyrax song is certainly not as beautiful as that of a nightingale, but it is interesting. Mostly it is the males that sing, and mostly it’s the dominant male of a group. Although they don’t dig their own burrows like rabbits, they colonize piles of boulders that litter the landscape of the Middle East – and there are boulder piles everywhere. In fact, Jewish legend tells the story that, when God created the Earth, he sent an angel out from Jerusalem with a sack of boulders to distribute around the whole world. Unfortunately, the sack had a hole in it … and so boulders now litter the landscape of the Middle East. Each morning, after warming up on the sun-soaked rocks, the hyraxes cautiously set forth to forage on the tough leaves and grasses. One individual usually places itself on a high rock and keeps an eye out for danger, and on hearing a barking warning, everyone rushes back to the crevices in the rocks that are impenetrable to predators. A big group means that individuals can take turns in being sentinel, and that keeps everyone safe. I’ve watched a fox wander through a group of feeding hyraxes, who eyed him warily but continued eating – as long as the fox was being watched, it posed no real danger. So, living in a group makes a lot of sense if you’re a hyrax, if only to keep you warm and to have an early warning system against possible predators. But when you live in a group, there’s always competition of some sort. When everyone has enough food, it’s usually mating that becomes the source of conflict. Mostly, females stand to benefit from a large group – lots of eyes means your babies are safer than they would otherwise be. But for males, the competition to reproduce is intense – one male could in theory mate with every single female, and if you’re a male hyrax, the big evolutionary prize is to do exactly that: monopolize the females around you, making sure you’re the only one who does any mating. The males are engaged in a never-ending dominance struggle, and typically, a single male in every group wins out, and becomes the big boss.

It’s hard to miss the dominant male in a hyrax group. He’s big, he occupies the highest rock. And he sings. Perched on his rock, surrounded by females and by immature males, he calls forth his singing voice and cries out. Over and over again. And then some more. An absurdly large proportion of a dominant male’s day is spent singing. Why? Probably partly to advertise the group’s territory, but the evidence indicates that the real reason for singing is to intimidate the other males, and to establish himself as the dominant one. After all, in the bleak wilderness of the Middle East, where sparse vegetation isn’t much better on this pile of boulders than it is on that one, territories are fluid, and hard to enforce. Like wolves, hyraxes need to move around to find enough good food, but unlike wolves, they feed on leaves and plants all the time. A pack of wolves could potentially try to stop strangers from hunting deer in their territory – if they spot them – but it’s much harder to stop strange hyraxes from nibbling on the woody shrubs that are, after all, spread out all over your territory anyway. A dominant male may try to defend his residential boulder pile from being taken over by neighbouring groups, but attempting to defend his food resources seems futile. And so we think that, for a male hyrax, song is really aimed at defending his females, rather than defending his thorn bushes.

One way to assert your dominance is to fight. That’s certainly an unequivocal show of power, but it’s also a risky strategy: male lions, for example, can fight to the death for leadership of a pride. Other animals take a safer course, and establish their dominance through display and intimidation: a stag might have particularly large antlers that intimidate other male deer, and even if it would rather not use them for fighting, they’re still a sign of a strong and powerful individual. Or a male bird might have particularly bright plumage – a good sign that he’s healthy, and well fed. The hyrax prefers to sing some really good songs. Just as with human singing, we know that some hyrax songs, and some hyrax notes, are harder to sing than others, and the male that can make the most impressive song is making the biggest impression on his potential rivals. You don’t want to mess with an impressive large male hyrax – whether you’re a smaller male or an inexperienced researcher. I’ve been at the business end of a pair of razor sharp hyrax tusks when I thought a male was more deeply anaesthetized than he was. Very thick leather gloves saved me from an embarrassed visit to A&E.

Male song is what zoologists call an ‘honest indicator’. You can bluff and fake in all kinds of ways, but not in singing. Either you’ve got the tunes, or you haven’t. Bigger lungs, tighter control of your vocal cords, and probably even a better brain, all contribute to the quality of your song, and if you can sing a good song, perhaps a complex song, you’re genuinely a stronger, fitter male. So potential challengers, as well as breeding females, pay close attention to the kind of song that a male sings. Impressing your rivals, and your potential mates, is an important skill.

It’s the same with humans. You can probably see that singing a complex song would bring more kudos than a simple one. Think about how you might try to impress everyone with a karaoke version of ‘Bohemian Rhapsody’. (I tried it once. My friends and colleagues begged me not to do it again, so I guess I wouldn’t make a good dominant hyrax.) Anyway, research has shown that song complexity, both in birds and in hyraxes, is a good reflection of how fit, healthy, and capable an animal is, and also indicative of how attractive he is to females. Song complexity is the equivalent of peacock feathers for some animals, and the hyrax is one of them.

So, here we are with a social animal – social for simple reasons like protection from predators – and an animal with a reason to have a very complex communication – for a male to advertise his charms to females. They don’t actually say a lot beyond ‘Come mate with me’, but they say it in a complex way. That simplicity of message, but complexity of medium, is an important cornerstone in the evolution of language, even if it comes from an unexpected animal. What exactly is going on?

Wail, chuck, snort, squeak, and tweet

One thing that makes hyrax songs very easy to analyse is that they combine only a few distinct kinds of sounds, or ‘notes’, since hyraxes have a very limited vocabulary. This contrasts with wolves and dolphins, where the different kinds of whistles and howls seem to blend into each other. To make things easy for ourselves, we give each of these hyrax notes vaguely descriptive names, which, despite being fanciful, help to distinguish them. When I was working with hyraxes, I catalogued five distinct notes: wail, chuck, snort, squeak, and tweet, and I think the names are pretty descriptive.

34. The spectrograms of five different hyrax notes that I discovered in my research. Wails are long, descending notes; chucks sound like a rapid series of knocks; snorts sound like, well, snorts; squeaks are short and of a fairly constant pitch; and tweets quickly rise and fall in pitch.

Hyraxes combine these notes into long songs, typically about thirty notes long, take a short break, and then start the whole thing all over again. It’s fun for a field researcher like myself to hear, but other local residents can find these songs somewhat frustrating: an irritatingly healthy hyrax might sing pretty much continuously for over an hour, and I’ve had many people approach me and ask, ‘How do you stop them singing?’ Hyrax songs can be as loud as 80dB, a level that the American Society of Audiology compares to ‘alarm clocks’. Annoying as they are, however, few alarm clocks are quite as annoying as the grating discordance of a hyrax. Although repeated wails and snorts may sound like a chaotic cacophony, there’s something very interesting going on: the successive songs of a particular male are almost never identical. Compare that with songbirds, many of whom learn their songs when they are young, and then continue to sing the same song, almost precisely, for the rest of their lives. This is most definitely not the case with hyraxes. Now, whereas every songbird sings a song that is slightly different from his neighbours, thereby providing a useful way to identify who controls which territory, there’s still essentially only one song, and one message for each bird’s song: ‘It’s me, I’m here.’ A hyrax, in contrast, will sing different songs one after the other. In theory, each song could have a different message. It could be a language … in theory. The diagram shows two examples of short hyrax songs, just fourteen notes long.

35. Two short hyrax songs.

Although you might think that, with just five notes to choose from, the songs are going to be repetitive, this is not the case. Those two examples are just two out of 5¹⁴, or more than six billion, possible combinations. And for the full thirty-note song, there are almost a thousand billion billion possibilities. Now, not every one of those combinations is going to be used – there are physical constraints on what sounds go together. I’m sure as a child you tried pronouncing ‘pterosaur’ as ‘p-terosaur’ (it’s not – it’s pronounced ‘terosaur’). You can follow a ‘p’ with a ‘t’, but it’s not easy, and most languages tend to avoid such lingual acrobatics. But even with these constraints, you don’t need a very large vocabulary to make a very wide range of different messages. If we take the analogy of the sentences in human languages, with each note being a ‘word’ and each song being a ‘sentence’, hyrax songs would not have to be any longer than seven notes to have enough unique combinations to cover all the approximately 37,000 sentences in Tolstoy’s War and Peace.fn1 So combining notes into songs, or words into sentences, has tremendous power to contain and convey information; really, really large amounts of information.

But the raw ability to create distinct sentences isn’t the end of the story. We know from our own language that it’s not just the words in a sentence that matter, it’s the order of those words in relation to each other that fixes a lot of the meaning. It is precisely because the order of words matters that language can be so flexible. ‘The fish bit the child’ is clearly different from ‘The child bit the fish’. But just because we humans often depend on the order of words in a sentence to constrain the meaning, does that mean that animals must use the same system? Certainly not: we know that some species, like banded mongooses of southern Africa – small, playful social predators, looking rather like ferrets – pay attention only to which notes are in a sequence, not to the order in which they appear. And yet, most linguists would say that grammar – the way in which word order determines meaning – is essential, even necessary, for language. The claim behind such a bold, possibly anthropocentric, statement is that it’s hard to see at first glance how you could write 37,000 different sentences if you didn’t have a grammar to fix the relationship between word order and meaning. Grammar really does seem to be fundamental to language, or at least linguists struggle to see how a true language could exist without it. Indeed, when we learn a new language, the key elements seem to be vocabulary – the five different hyrax notes – and grammar – the way that the vocabulary is combined to create different meanings. As I explain in the endnotes, language is grammar, so the story goes.1

Does this mean, then, that the birds and mongooses that don’t pay attention to note order can’t possibly have a language? Is their communication system too restrictive and inflexible to demonstrate the full power and descriptive capabilities that we have?

Mathematically, that doesn’t seem to be the case. You can put a lot of information into a song, even if the order of notes is ignored. I said that you only need a seven-note hyrax song to write War and Peace, because there are so many different ways of ordering the notes. But it would still be possible to write Tolstoy’s 37,000 unique sentences using our five possible hyrax notes, even if ordering didn’t make any difference. True, it would be a lot less efficient, and the sentences would have to be longer to remove ambiguity, because sentences like: ‘So you have never noticed before how beautiful I am?’ and ‘I am never beautiful, have you noticed before how so?’ would mean exactly the same thing if the order of the words had no significance. If a hyrax were to write War and Peace without any reliance on note ordering (so that Wail-Wail-Chuck means the same thing as Chuck-Wail-Wail) they’d need a twenty-nine-note song instead of a seven-note song.2 But a twenty-nine-note song is well within the animal’s capability. While such a system is theoretically possible, it’s a bit of a mess – it’s inefficient, and it’s easy to get confused about the different meanings. At least in human language, the order of the words we use provides exactly that: order. We can easily spot patterns in sentences, and these patterns reflect elements of meaning.

To summarize so far: we feel that our complex language grammar is what really makes a language into something special (and nowhere do you feel that complexity as much as when you’re struggling to learn a new language). But many animals – hyraxes and songbirds, certainly – have rich and varied songs, which may or may not contain complex information, and that information may or may not depend on the order of the notes. We don’t know if they have grammar or not. We certainly could write complex sentences that have lots of different meanings, even if there were no grammar, no significance to word order at all. And yet scientists and linguists – and even non-scientists, if you’d stop and ask them – make such a fuss about syntax and grammar, holding them up to be the big sign of language. Is there any way we can determine whether animals use syntax, and if so, why?

Rolling multi-sided dice

This all might sound like a perplexing quirk of linguistic theory, but it’s actually to do with what’s going on inside animal brains. Animal brains evolved to provide a way to sense the world outside, and to control the body in which the animal lives. Communication has shaped the evolution of brains, but these organs, amazing as they are, still evolve under constraints of the natural world, and so brains should be complex enough to perform the communication needed by an animal, but no more complex. Brains use a lot of energy, they’re potentially quite fragile, and, at least in the case of humans, they take up quite a large part of the body. It is this balance between complexity and simplicity that determines how animal brains have evolved in some species to communicate without any consideration of order, and in other species to take order into account. When small birds like chickadees see a predator at a distance, they say, ‘seet!’ When the predator is closer, they say, ‘seet! seet! seet!’ – a bit like parking sensors on a car. The entire meaning of the message (how much of a threat is looming) is explained by the number of times that the alarm call is repeated. Simple message, simple mechanism. Even animals like hyraxes with complex songs resort to simple calls when they suit the situation best. Alarm calls can’t be complex – they require instant understanding and an instant, unequivocal response. For a tiny animal that you can hold in one hand, hyraxes can be pretty scary when twenty or more come running at you in response to an alarm call. ‘Let’s go get him!’ is a simple and effective message, so hyrax alarm calls have a lot more in common with chickadee seets than with the much more common male display songs.

It has been known for almost half a century that the larger the repertoire of some male songbirds, such as blue tits, the more likely a female is to mate with him. Complex combinations are not needed – simply the more different types of song a male uses, the better. However, when I want to explain the effect of Napoleon’s invasion of Russia on the Russian aristocracy – as in War and Peace – such simple mechanisms are no longer effective, and relying on the order of words is important for increasing the information content in the message. That means that we as scientists can say something about the nature of the possible content of a message – i.e. how much information there is – by looking to see whether combinations seem to matter, or whether order is of no importance.

36. Being mobbed by a pack of wild hyraxes is no joke. Their simple alarm calls are an effective way to bring the power of the pack down on an unsuspecting predator. In this case, me.

We’ve seen that hyraxes have the potential to sing many different songs: many thousands if the order of the notes doesn’t matter, or many billions if the order does matter. Now that may sound like a lot of possible songs, and a lot of possible information, but what’s fascinating is that hyraxes don’t exploit that full range of possibilities. Not even close. Although it’s true that the same song is rarely repeated precisely, that’s not the same thing as saying that the songs are chosen completely at random. This is particularly noticeable in short songs: there are only about 3,000 possible five-note songs, but if you listened to 3,000 such songs, they wouldn’t all be different. About 1,000 of them would be repetitions of a song you’ve already heard. This tells us something very important: hyraxes aren’t just choosing their songs randomly. If hyraxes were just randomly deciding what note to sing next, you’d expect the songs to be much more different than we observe, with very few repetitions of the same short song. That means there’s some process, some structure to their song. Just like a musician who composes music not by randomly combining notes, the hyraxes don’t randomly mix up their songs. Something is constraining how they put their notes together. And that something we might want to call ‘syntax’.

Syntax like this has been clearly demonstrated in many animal species, from starlings and nightingales to pilot whales and bats. Syntax is so widespread that it seems to be the rule, rather than the exception. But how does this sit with my previous statement: that if we see that the order of notes matters (syntax), it might imply that the song contains a lot of information? It seems rather unlikely that every one of these species is telling each other stories of the complexity of Tolstoy, so although syntax may or may not be necessary for language, it certainly doesn’t appear to be the case that just any communication system with syntax can be called a language. Why, then, is syntax so prevalent? To answer that, I’m going to have to describe a little bit more rigorously what syntax is.

First, imagine that you have a five-sided die labelled ‘wail’, ‘chuck’, ‘snort’, ‘squeak’, and ‘tweet’.fn2 You roll this die repeatedly in your head to decide what note to sing next. If the die is ‘fair’ (i.e. equally likely to land on any particular face) then you’ll end up singing each particular note one-fifth of the time. Of course, that’s not realistic – some notes are harder to sing than others, and so are less common. Let’s assume therefore that the die isn’t fair – you’re more likely to be singing a tweet than a snort. This is, in fact, what happens with hyraxes, as snorts are difficult to produce, and more likely to indicate a strong dominant male, rather than a young inexperienced one. But still, if all you’re doing is rolling a die, the songs that you sing are not going to be very tightly constrained. A song might start with a wail, but also might start with a chuck. If you’ve just sung a squeak, the chances of singing a second squeak are no different from the chances of starting a song with a squeak. The type of note you sing is in no way affected by the note or notes that came previously. This is what we mean by a random song, and an absence of syntax.

If syntax is present, however, then the next note you sing does depend somehow on the notes that came previously. There are many ways that this dependency can play out – many different kinds of syntax. But it’s easy to analyse an animal song and see whether it is random or syntactical.

… am I likely to continue with a …

Wail
Chuck
Snort
Tweet
Squeak

If I start with a …
Wail
10%
21%
45%
14%
9%

Chuck
7%
24%
45%
16%
8%

Snort
6%
11%
63%
9%
10%

Tweet
9%
20%
22%
37%
12%

Squeak
8%
12%
33%
18%
29%

Hyrax syntax.

In the table, you can see that, following a wail, it’s very likely you’ll make a snort (45% chance), but a snort is hardly ever followed by a wail (6%). So, the chances of singing a particular note really does depend very much on which note came before. Hyraxes are not just rolling dice to choose what to sing.

Is it surprising that animals should have such complex rules determining the order of their notes? Can we assume that because syntax is so widespread, then so is information, and possibly language? The answer to both questions is ‘no’. In fact, if the answer to the first question is ‘no’, then it should be clear that the answer to the second is likely to be ‘no’ as well – if syntax is common, unsurprising, and unremarkable, then we can’t use the presence of syntax to imply sophisticated language-like abilities (although, of course, it doesn’t discount them either).

The reasons syntax is so common and unsurprising start in the brain. Brains are pretty good pattern generators – our brains can be relied on to make regular, repeated patterns that drive our legs while we’re walking, flap our wings if we’re flying, and even keep our lungs breathing and our hearts beating. Continual repetition is fundamental to how all animals work. So, it’s not surprising that animals often make the same sound over and over: birds go ‘seet, seet, seet’, cows go ‘moo, moo’. If you’re more than likely to repeat the same sound, then random sequences of notes cannot be the norm: your next note does depend on what note came previously. And this is what we find in the animal world. A few years ago, my colleagues and I showed that across a wide range of species, syntax appears to exist, and that it seems to go hand in hand with a tendency to repetition. Although we can’t prove that this is an evolutionary trend, i.e. that syntax evolved because animals tend to repeat notes, it’s a good hypothesis. Certainly, the prevalence of repetition explains why we see syntax across so many species.

A hyrax’s music lessons

Hyraxes have another trick up their sleeve. Apart from having complex songs, and non-random syntax, they have the ability to learn their syntax. This is really rather uncommon in the animal world – why would hyraxes have such an unexpected skill?

Songbirds are an example of animal communication that is familiar to pretty much everyone. If you live in northern Europe, no doubt the European robin and the common blackbird are familiar sounds – even if you don’t recognize which bird is which. Robin and blackbird song is complex and rather chaotic, but in contrast, another European bird, the chaffinch, has a rigorously uniform song that barely varies from rendition to rendition. Young male chaffinches learn their song from the other males that they hear around them in the first year of their lives. If a chaffinch grows up not hearing any other birds of his species (e.g. alone in a cage), he still develops a song, but it’s a pretty rubbish song – nothing like the virtuoso performance of which he is innately capable. Conversely, once a bird has learned his song, nothing will move him from it – even if he hears better songs all around him every day. For those of you in North America, the song sparrow has a similar tale to tell. Many songbirds go through this critical learning phase when they are young, and after that, no more song learning is possible. For those species, while it’s certainly true that a male bird advertises his fitness with the complexity and fidelity of his song, he is a one-trick pony – he’s tied into one single song for life. Not all birds have such a lifelong constraint on their learning ability. Mockingbirds are ‘open-ended’ learners – they can pick up and copy the song of another bird at any stage in their lives. As a result, mockingbird song is unpredictable and varied. But even if you’re the kind of bird that learns its song just once and then is stuck with it, that very learning is done by copying the animals around you. You hear the local males singing their song, and you sing something very similar – with a few personal innovations, naturally. That combination of local fidelity and innovation means that birds in a particular area sing a similar song to each other, and birds from further away sing a more different song. Birdsong dialects will develop.

So far, so good. Learning leads to geographic variation in song, and to dialects. But you don’t need syntax for this. Or, rather, you might or might not pay attention to syntax, and still get the same result. If I hear someone whistling a catchy tune, I can easily copy it – but as a non-musician I have not the faintest idea how the composer of that tune wrote it, and I certainly wouldn’t be able to write one myself based on the rules of music composition. (Indeed, I didn’t even know that rules of musical composition such as the ‘circle of fifths’ existed until my son Benji began playing jazz piano.)

I am like a chaffinch. I have no idea how to compose music, I just copy what I hear from others. But some species are like Benji. They spot the syntax in a song and can copy that. The hyrax is one of those species. Quite contrary to expectations, hyraxes don’t just copy the songs they hear – they pick up on, copy, and improvise on the syntax. Does your neighbour always follow a wail with a snort? Then maybe we should do the same – except occasionally add a tweet instead of that snort. Now, what we find is that hyrax groups living in close proximity have similar syntax, and as the distance between them increases, the difference in syntax becomes more and more pronounced. In northern Israel, near the Sea of Galilee, there is a long, narrow canyon filled with hyraxes. Each group of animals occupies its own pile of boulders, and the dominant male sings his own song. But because the canyon is so narrow, the hyrax dens are stretched out along this narrow path: thirteen colonies in less than three kilometres. And as you walk along this desert track, the song changes. Moving from one rock pile to another, the syntax of the hyraxes varies slightly from colony to colony. Clearly, each dominant male is copying the syntax of the animals on either side of him. This seems at first sight a very peculiar phenomenon. Why are hyraxes so attuned to the syntax of their neighbours, and not to the song itself? Surely it is easier – evolutionarily more efficient – simply to copy the song, rather than needing a brain complex enough to copy the actual syntax? I think that the explanation for this is rather straightforward. Hyrax songs are long – long and varied. To remember and learn from a song would actually be harder than picking up the general rules for creating a song that sounds right, in the same way that jazz improv sounds right, and not just like random notes. Here, evolution has (as usual) favoured the simpler and more effective solution – but in doing so, has opened up new possibilities for complex communication. Recognize syntax, rather than sequences of notes, because it’s easier. Once you understand syntax, you could use it to encode meaning … if you had need of that.

37. Strung out along a narrow canyon, each hyrax copies the syntax of his two neighbours. It’s easier than copying the song itself.

38.

Now we have animals whose communication is complex – they produce sequences of different notes, with many different combinations, but not all of those combinations are equally likely. There is structure, there are rules dictating how to combine notes. And whatever rules they come up with, they can learn those rules from each other. On the face of it, you might think that all these rules actually reduce the complexity of communication – if not every combination is allowed, there are fewer possibilities, fewer sentences, fewer books that can be written. But that is not the case. In fact, those constraints, rules, syntaxes, learning, are precisely what enable the next step: from syntax to meaning.

Where is the meaning?

What is it that makes a bird or a hyrax song mean something? This is a question for which we don’t have a complete answer. Partly because we’re only starting to scratch the surface on meaning in animal communication – and there seems to be a lot more meaning going on there than we used to think. But partly also because meaning probably exists in many different places at the same time. I’ve already mentioned one: the hyrax that can produce snorts or can sing a long series of chucks in one breath is saying, ‘I’m a stronger, fitter male, because I can make this crazy sound that other hyraxes can’t make.’ That’s much simpler than syntax – it’s just meaning that exists by virtue of the number of times you use a particular note, irrespective of the order of those notes. We know that syntax exists – must exist, because the order of the notes isn’t random – but does that mean that hyraxes (or other animals) also have real, genuine meaning in that syntax? Or is syntax just a distraction, contributing nothing to the message?

Actually, there’s good evidence that many animals – including hyraxes – make use of syntax to convey messages, just as they make use of repeated notes. Our research has shown, for instance, that hyraxes sing more complex songs – the rules of their syntax are stricter – when there’s an audience of other hyraxes listening. In other words, a hyrax singing to himself will sing relatively simple songs, but when there are lots of females listening to him, he really makes an effort to produce an impressive, complex song. Now, that doesn’t necessarily mean that the hyrax understands why he’s making a complex song, and it doesn’t necessarily mean that he intentionally makes his songs more impressive either. Identifying whether an animal intends to do something is notoriously difficult – and some people would say that animals have no intentions at all. But intention isn’t necessary for us to call something ‘meaningful’. A peacock with bright tail feathers is sending a meaningful message to females about his physical prowess, but he probably has never taken any notice of how beautiful his feathers look (he may not even have seen them). What’s important for something to be called ‘meaning’, is that it should have an effect. Brighter peacock feathers mean that a male is more likely to mate. It’s not always that easy in practice to measure what effect different kinds of syntax have, but when we see how hyraxes alter their syntax according to the social context, the social status of the singer, and the type of audience, we’re confident that this syntax contains some kind of meaning.

So where exactly in the syntax does the meaning lie? So far, the answer to that has been clear-cut: meaning lies in complexity. The more complex the birdsong, the more attractive it is to a mate. The more annoyed a hyrax is with his neighbours, the more complex a song he’ll sing to intimidate them. Complexity is a good sign of fitness: complex colouring in the feathers of a bird of paradise shows that the bird is well-fed and healthy, and a complex song shows that the singer is fit and capable – just like a really good rendition of ‘Bohemian Rhapsody’. It should be intuitively clear that something complex is in some way harder to produce than something simple; hence complexity can be a kind of honest signal – it can’t be faked unless someone actually has that skill. But what really is complexity? Pinning down a definition of complexity with which everyone will agree isn’t easy. If a hyrax is rolling a five-sided die in its head, we don’t think that’s complex. If, on the other hand, the hyrax is always doing the same thing, for instance always following a wail with a squeak, that’s not complex either. Complexity is somewhere in between: not so random that you’re just making stuff up, but not so stereotyped that you’re always saying the same thing. Fortunately, this is a statistical signature that is easily measured, and in our hyrax work (and in a lot of other research on birdsong, for instance), that is exactly what we find: complexity, without randomness.

When it comes to human language though, clearly meaning doesn’t just lie in complexity – there are complex rules of grammar that hold meaning, and just relying on ‘more complex’ vs ‘less complex’ doesn’t give much scope for talking about the intrigues and dubious mores of Russian high society. But the complexity spectrum does teach us something extremely important: complexity in communication probably evolved to support a range of meanings in messages. Animals that had a simple call could say only one thing. The ability to have a more complex repertoire gave more scope for saying more things. That’s the likely evolutionary origin of syntax, and of grammar. Animal syntax is the foundation of our own grammar: what we recognize as the essence of our own language. But animal syntax is not the same thing as grammar, it doesn’t have the same structure, and it doesn’t fulfil the same role. Animals use syntax to convey meaning, but not to convey complex meaning. We humans have taken the complexity of syntax and refined, elaborated, and extended it so that a much, much wider range of meanings can be incorporated.

Language means many things to many people. There are things like computer languages, which have been designed by human intelligence, rather than having evolved on their own. There is also a lot of theory that extends the concept of language to cover general algorithms as well (algorithms have a ‘language’ of their own). Language also means that subject you were forced to learn in school, where you have to remember that in French, ‘chat’ means the same thing as ‘cat’, and ‘salade’ means the same thing as ‘salad’. But when we talk about language (at least, when I talk about language in this book), I’m talking about natural language in general, i.e. that which evolved through natural selection. And this is important because traits evolve through natural selection only if they provide a concrete benefit to an actual living organism – something that can reproduce and pass on its own traits to its offspring. If language doesn’t work for a real animal, it won’t evolve.

That requirement for a step-by-step advantage to language innovation has confused many people trying to understand exactly how human language evolved. We have grammar, where the precise ordering of words conveys subtle differences in meaning; animals don’t appear to have anything similar. An animal can only make a song more complex or less complex. What were the intermediate steps between what we see in the animal world, and the sophistication of language? How did simple animal syntax slowly morph over the generations into the language we understand?

These are questions that we can’t answer completely. There are no fossils of language to study, and so we never get to see those intermediate forms. We can only talk about what’s possible, what’s likely, and what’s reasonable, according to the rules of evolution that we know. We know that syntax is widespread – essentially ubiquitous among animal communication. Animal brains are capable of distinguishing differences in word order, even if there’s very little meaning to those differences. There doesn’t need to be any meaning to the differences because that perception of difference, that understanding of syntax, provides a benefit in itself. It allows animals to distinguish between a powerful singing performance and a mediocre one. Somehow, our ancestors refined that ability. Messages became clearer, more precise, more specific. Perhaps particular word-order combinations became ritualized and took on meanings of their own. Once enough such phrases existed in the repertoire of these ancient pre-humans, there would be a distinct advantage to having a brain that could understand patterns in such phrases, and perhaps from that our true language ability was born. The hyrax, a weird animal, not quite a living fossil, tells us that syntax in animals is fundamental, and probably ancient. More than that, this little animal, who can’t even digest grass effectively, actually uses syntax to communicate, and to convey messages through complexity. Those messages have been going around between animals of many different kinds, probably as long as animals could make sounds at all. And our ancestors just hitched a ride on that ability.

Speculation is unfulfilling. Without fossils, how can we investigate the origin of language any further? One possibility is to go back in time to the point somewhat before language truly evolved, and to see what happened to those animals whose lifestyle never placed such emphasis on complex meaning, who never had the need to adapt their syntax into a grammar that supports sophisticated concepts. Who were those creatures? How did they differ from their cousins, our language-speaking ancestors? And what became of their descendants? The time has come to look at those greatly misunderstood animals whose progenitors took a slightly different path to our own. Apes we are – but speaking apes. What of those apes who never evolved language?

39.

5. Gibbon

Nestled in one of the most remote corners of Vietnam is a pleasant valley filled with rice paddies and tiny villages. On either side of the valley rise perilously steep mountains covered in dense vegetation. This ring of peaks forms a wall, a barrier that seems almost impenetrable. But penetrate it we must, if we are to find our quarry – the exceptionally rare cao vit gibbon. Climbing that first sheer slope feels like walking into Mordor. And indeed, after several hours of clambering up and skittering down, cutting our way through the jungle, we arrive in a world that feels completely isolated, entirely removed from the human world. Just a day’s journey from the bustling, seething mass of humanity that is Hanoi city, this seems like a lost realm. Only the unnatural tracks of the artificial satellites among the stars remind you that this is the twenty-first century, and you are not likely to encounter some species of dinosaur, previously thought extinct, around the next tree. But that’s not entirely true. Here, in the most isolated of habitats I’ve ever encountered, was discovered just twenty years ago a species of animal thought to be extinct for more than a hundred years. At five in the morning, I stir in my hammock as an eerie, unearthly sound penetrates the jungle. Resonating through the trees comes the call of the male gibbon: ‘Caaaao vit. Cao vit vit.’ Soon, more voices join the chorus, and then a sudden cacophony of warbling, ululating sound that is the female response. Peering through the leaves, I see furry figures that look almost human, save for the exaggerated length of their arms, swinging from tree to tree in the canopy. It is a very, very strange experience. Here, surrounded by inhospitable mountains and valleys, the gibbons are talking to each other. But what are they saying?

40. The cao vit gibbon.

‘I cannot doubt that language owes its origin to the imitation and modification, aided by signs and gestures, of various natural sounds, the voices of other animals … some early progenitor of man, probably first used his voice in producing true musical cadences, that is in singing, as do some of the gibbon-apes at the present day.’

Charles Darwin, The Descent of Man (1871)

Meet the apes

We humans are apes: primates without a tail. Few such peculiar creatures survive in today’s world. Apart from us there are chimpanzees (and their close relatives the bonobos), gorillas, orang-utans and about twenty species of gibbon. Gibbons are the most distantly related to us: we went our separate evolutionary ways about twenty million years ago, whereas we shared a family ancestor with chimpanzees just six million years ago. And yet of all the apes alive today, only humans and gibbons use complex sounds for communication. Chimpanzees – for all their human-like intelligence – have a quite restricted range of vocal signals. In contrast, some species of gibbon, like the white-handed gibbon, have such a range of sounds, and such complex ways of combining them, that their communication almost seems to resemble human speech. These are genuinely special creatures. Apes as a whole, these intelligent, tailless monkeys, have evolved to display a complex cognition that seems to surpass almost every other group of animals – and have given us a few instances of truly complex communication: humans and gibbons. Why are there such things as apes, and where do we come from?

Struggling out of base camp up a 45-degree slope of jagged rocks, overgrown with bamboo and slippery moss, we clamber, almost on all fours, up to the mountain peak where we have placed a recording device to monitor the sounds of the cao vit gibbon. A break in the bamboo gives onto a rocky, vegetation-free plateau, and an unbelievable vista is spread out below us. As far as the eye can see, kilometre after kilometre into the distance march mountain ranges steep and triangular and completely covered in dense jungle. It feels as if jungle might cover the entire planet. Indeed, twenty million years ago that was pretty much the case. From here, on the far eastern shores of this massive continent, all the way to the rich biodiversity of Africa, ran nothing but jungle. For thousands upon thousands of kilometres. And in far-away Africa, a new evolutionary experiment was taking place. Monkeys that, instead of running along branches with a long tail to balance themselves, would instead swing arm over arm beneath the branches, passing from one tree to another with absurd ease and speed. Particularly suited to the dense jungle, these creatures burst out of Africa and sped across Central Asia, into China and the Far East, adapting, changing, and suiting themselves to the environment, generation by generation, as they went. Sitting on that rock plateau under the observation post named D2, one could almost see these ancient gibbons, swinging from tree to tree, moving along mountain ridges with ease, covering the distance between continents perhaps in just a few generations. You don’t really appreciate just how efficient those long gibbon arms are until you try to struggle through the jungle yourself.

In those early years of ape evolution, the gibbons spread throughout Eurasia and adapted themselves well to jungle living. Like the grey parrots we met in Chapter 3, gibbons feed mainly on fruit, and finding the tree with today’s ripe fruit requires some impressive cognitive skills. For one thing, a good memory to recall which trees are in your territory, which ones have ripened recently, and which are yet to ripen. Gibbon social groups are led by an experienced female, who has foraged her territory for years, and is familiar with all the details of how to find and access the best food. Primates in general, and apes in particular, thrive by being smart: using large eyes, large brains, and dextrous fingers to investigate, consider and manipulate their environment. Those cognitive abilities are impressive in themselves, but for our purposes, their interesting role is in setting the scene for complex communication. Once you’ve got a good brain, you can use it to speak – if, of course, speaking is to your evolutionary advantage.

41. Jungle like this in Vietnam once covered much of Eurasia.

The music of the gibbons

Of the twenty or so species of gibbon alive today, the best known and the best studied is the white-handed, or lar gibbon. Although all gibbons look pretty similar to the untrained eye – ‘monkeys with long arms and no tail’ – the lar gibbon is as distantly related to the cao vit as we humans are to gorillas: humans and gorillas have a common ancestor from about 8.5 million years ago – the same time that the common ancestor of these two types of gibbons existed. And, like humans and gorillas, they still share many features. All gibbons use their long arms to swing through the trees looking for fruit to eat, and all gibbons sing. Lar gibbons, however, have the most complex vocalization of any (non-human) ape. The most prominent songs are sung at dawn by the adult female and her mate. Lar gibbon song, like that of the the cao vit gibbons whose striking and haunting songs penetrate the early morning mists of the Vietnamese jungle, and indeed all gibbon song, probably serves at least two purposes. As in many animal species, song can be territorial. Birds sing to advertise that this tree or this field belongs to them. Similarly, wolves howl to advertise their presence and warn away other packs. It would be surprising if gibbon song didn’t fulfil the same role, and indeed it seems that singing is at least partly a way of advertising their presence to other neighbouring groups of gibbons. Fruiting trees may be plentiful in the jungle, but they are valuable, and a family group that can monopolize a region of forest will be more successful than a group with no clear territorial boundaries.

The second role of gibbon song appears to be in strengthening the bond between a mated male and female. It sounds so romantic: singing a duet with your partner as soon as you wake up each morning to keep the romance going. Despite perhaps being far too anthropomorphic in the literal sense, this description nonetheless captures the essential role of gibbon duets. Constant reinforcement of the bond between male and female ensures that they continue to work together for the welfare of the group. The better they can sing together, the better they can cooperate: finding food, raising young, and defending their territory. A well-rehearsed and coherent duet also advertises to nearby gibbons that here is a well-matched, strongly bonded pair: roving animals, both male and female, are always on the lookout for sly casual copulations with individuals disaffected with their current partners. As I’ve pointed out in previous chapters, complex communication often sends no message other than the complexity itself – if my partner and I can sing a complex duet together, we have clearly been practising, so don’t try to muscle in!

42. A duet between a female and a male lar gibbon.1

Darwin drew a direct line between the duets of gibbons and the singing of humans, even explicitly assigning both the same name and implying the same role: ‘… producing true musical cadences, that is in singing, as do some of the gibbon-apes at the present day’. But is this anything more than a superficial resemblance? Perhaps, overawed by the complexity of these loud and intricate songs, Darwin merely felt they should have correspondingly more significance than the braying of zebras or the hissing of lizards. And yet Darwin was remarkably insightful about the role and meaning of different animal sounds and signals. He identified that male birds sing to attract female birds, and that male gibbons sing to attract female gibbons, but it struck him as particularly relevant that the female gibbons sing too. Somehow, the act of courtship in certain animals – mostly birds that pair-bond monogamously, like swans and albatrosses, not to mention the parrots of the earlier chapter – was a two-way street, with both males and females trying to impress each other. This is not surprising. Where a male simply impregnates a female and then leaves to find another conquest, he can afford to lower his standards. But if a male and a female are going to cooperate in the raising of young – possibly cooperate over very many years to make sure their offspring grow, learn, and survive to become successful themselves – then choosing the right wife is just as important as choosing the right husband. And this is what happens in gibbons. At the risk of adopting too much of Charles Darwin’s slightly soppy obsession with mating, here’s another quote from The Descent of Man: ‘Music affects every emotion, but does not by itself excite in us the more terrible emotions of horror, rage, etc. It awakens the gentler feelings of tenderness and love which readily pass into devotion.’

The gibbon families today that sing together are performing an important task. The male and female are doing more than just demonstrating their bond, they are reaffirming it, and thereby strengthening it. Even more than that, their young are learning about singing, learning about impressing their mate, and thereby learning how to find and keep a good partner who will help them raise successful offspring. Young female gibbons sing with their mothers, attempting to copy her complex songs and hone their own singing skills. Contrast this with male birds, who learn their songs rather passively – young male birds will ‘babble’ as they experiment with copying the song of birds around them, but there isn’t a direct attempt at tutoring by the adults. However, gibbon mothers actively change their songs to help daughters learn, adjusting the pitch and tempo until the young can match them accurately. This is quite remarkable, and certainly implies that the precision of the female’s song performance is terribly important.

Even 150 years after Darwin, scientists today believe singing to be a key part of the evolution of human language. Exactly how and when our ancestors first began to speak in symbolic words, we don’t know. But for them to be able to make words, to say them out loud, required good control over their vocal apparatus – they needed to be able to make lots of different sounds. It’s an observable fact that humans can voice many, many more words than actually exist. Known as pseudowords, these sounds are – or could be – perfectly legal words in a particular language. Only they aren’t. There are many websites to generate pseudowords randomly, one of which gives me the following examples: Tran, Forme, Gestinct, Wicher, and Lation. A more light-hearted but similar application is the generation of fantasy names, typically used by players of Dungeons and Dragons, like Larongar Orinan, Alre Dorhorn, Ornthalas Ralokrana, and Filarion Cralar (all randomly generated). The point is that the rules of the language dictate only what sounds can go together and what sounds can’t go together – and those legal combinations of sounds may or may not mean anything. Illegal combinations also exist, and these are easily recognized: thwuivvs, phlurnts, shrougnth. How is it that we humans can make such a dizzying number of sound combinations? So many that even our rich language doesn’t have enough words to make use of all of them. Perhaps singing has an answer here. Our ancestors didn’t evolve such a wide range of vocal abilities so that they could invent multiple names with which to play D&D. Maybe they had their vocal ability so that they could sing. The advantage of having a wide vocal range – being able to sing to your partner – was later adopted and adapted for speaking. If that is really what happened in our evolutionary ancestors, then the singing behaviour of other primates isn’t just an oddity of a curious species of animal in a remote jungle. Singing may have laid the foundation of our present-day ability to talk.

But there’s a problem with this attractive idea: gibbons and humans sing, but our other close relatives – chimps, bonobos, gorillas, and orang-utans – don’t. We don’t really know much about our most recent common ancestor with chimps and bonobos six million years ago, but we’re fairly confident they didn’t sing. It seems far more likely that singing – and hence the vocal acrobatic ability needed for language – evolved separately not only in the ancestors of gibbons and in the ancestors of humans. Although gibbon singing isn’t directly a precursor of human language, the fact that it evolved in related apes at least twice in the last twenty million years does indicate that the ability to command our vocal system so precisely evolves relatively easily.

An amazing potential for complexity

Fascinating as the role of gibbon song is, the song itself isn’t particularly exceptional, relative to other species we’ve already discussed. As we saw in the previous chapter, hyraxes sing to advertise their territory too, and sing with complex combinations of notes. However, gibbon song is quite different from hyrax song in important ways. In fact, it is precisely the leap from hyrax song – with a small repertoire and loose syntactic rules – to the impressive abilities of the lar gibbon that is of interest in our story. Many animals sing, and many animals have some kind of syntax. How does that become language? Are there any important intermediate steps for which we should be looking?

43. The evolutionary family tree of the apes. Most don’t sing, but gibbons do, and humans do. So singing probably evolved twice, separately, in two different lineages.

Firstly, the repertoire of the lar gibbon is exceptionally large. Although early researchers divided the notes into just six different kinds based on what sounds different to the human ear, a more complex analysis, using a computer to break the sound down into its hundreds of different spectral components, has revealed twenty-seven distinguishable note types. Looking closely at the variety of sounds available to the gibbons, it’s clear that there is a lot of scope for variation. If the hyrax could make 3,000 different songs out of a five-note sequence, well, a gibbon could make 27⁵ or almost 1.5 million different songs. Secondly, however, gibbons don’t sing five-note songs – their songs can go on for three or four hundred notes. The number 27³⁰⁰ is too big for my computer to calculate, but it’s something like a 1 followed by 430 zeros. What on earth might be the point of that? Clearly, the animals aren’t conveying that many messages. I put forward an idea in the hyrax chapter that, rather than complex signals containing complex information, the complexity itself is the information: ‘Look what a complex song I can sing – I must be a very healthy animal indeed.’ However, while this may be convincing for a hyrax song of ten, twenty, or thirty notes, it still seems excessive to demonstrate your complexity with a song of hundreds of notes. Surely the listener will have forgotten how complex the beginning was by the time you got to the end!

This is indeed a difficult question from an evolutionary perspective. Why would an animal invest as much energy as it does (singing is very energetically demanding, as anyone in a choir or at a football match can tell you), and invest as much brain power as it does, thinking up such complex songs? What concrete advantage does such a long complex song provide?

44. Twenty-seven different kinds of lar gibbon sounds, as determined by machine-learning algorithms.2

One of my favourite pieces of music is the second movement of Mozart’s Piano Concerto #21. This piece, less than six minutes long, contains well over 2,000 notes on the piano. And yet, no one would suggest that some of these notes are unnecessary. We do not forget the complexity of the opening bars, just because, five minutes later, we are moved by the emotion of the closing bars. As humans, we can certainly comprehend the relevance of such a composition, and we readily accept that one 2,000-note piece of music has a different effect on us than another 2,000-note piece. Gibbons clearly lack some of the cognitive tools that humans possess, but can (and do) they attach some meaning – or at least some significance – to their own complex compositions? Clearly, music is not language in any sense that I’ve defined the word so far in this book, and yet the messages present in music seem diverse and almost infinite. But they are not specific in the same way that language is – different musical sounds do not directly refer to unique concepts in the real world. Even so, the ability to comprehend the wide diversity of signals in a musical composition may be an important stepping stone on the path to understanding the wide diversity of messages in a linguistic sentence. The idea of multiple non-specific messages that nevertheless contain a diverse set of information has everything to do with the evolution of language. And so, as Charles Darwin anticipated, gibbon song is crucial to the story of humankind.

How to go from one note to another

In the previous chapter, we saw that hyrax song has a syntax. Not every note follows every other note with equal probability. As I mentioned, that’s not particularly surprising. Most animals have syntax of some sort. At the very least that says that their communication is not completely random. But how much syntax does an animal have? We have an intuitive feeling that a chiffchaff has very little syntax (all they ever say is: ‘chiff’, ‘chaff’ … ‘chiff’, ‘chaff’ …), whereas a mockingbird, singing long songs of tens or hundreds of notes, has more syntax.

One way that we can investigate this is to represent animal syntax graphically. For example, we could place a label for each note type on a graph, and then represent the probability of one note following another (say, snort following wail) by the thickness of an arrow between the two (we’ll also put a number next to each arrow, to represent the probability more quantitatively). I’ve reproduced the hyrax transition matrix from the last chapter in graphical form overleaf (I’ve omitted very rare transitions, for simplicity). Now compare the syntax diagram of the hyrax to that of a lar gibbon. The hyrax diagram is simple, with a few arrows connecting the different notes: a big fat arrow from wail to snort, and a very thin one from chuck to tweet. However, the gibbon diagram looks more like a plate of spaghetti that’s been spilt on the floor.

Whatever the meaning of this complex syntax – if, indeed, there is any meaning at all – we can at least say that different evolutionary pressures have been acting on these two species, causing their songs to be strikingly different in complexity. Hyraxes need to sing complex songs to advertise their fitness. Gibbons seem to exceed that requirement by a long way. Something about the environment in which gibbons live, and the way that they cope with that environment, has favoured such a complex song. A song that can demonstrate personal fitness, but also a song so complex that it can take many, many unique forms. What evolutionary pressures could have brought about this ability?

There’s a simple answer that fits largely with our observations: it’s all about territoriality. If song is (at least in part) a territorial signal, then the more important it is to guard your territory, the more you might benefit from having a more complex song. Hyrax song is essentially personal rather than territorial, i.e. advertising the fitness of the dominant male to potential challengers both within and outside the group. It’s about protecting your personal status, rather than keeping other hyraxes away from your property, which is not surprising, as hyraxes have vague territories, fluid and overlapping between groups. Hyraxes eat leaves, and leaves can be found pretty much anywhere, so the animals can move around a lot – therefore, desperately clinging on to a particular patch of ground, forcibly excluding all others is largely a waste of energy. The leaves over there are just as good as the ones here. Now imagine that you eat fruit, like a gibbon. Unlike leaves, fruit is hard to find. Only some trees produce edible fruit, and as mentioned earlier, only some of those trees have ripe fruit at any one time. If you’ve got good fruit trees in your territory, it’s well worth the effort of protecting them. If another gibbon group takes possession of your fruit tree, you can’t just go next door to eat, as you’d be able to do if you were munching leaves. So, these scarce resources – fruit – encourage a species to be more territorial, and often to use the strength of the group to defend their territory from other groups. Interestingly, we find consistency in this variation: more complex song goes with more territoriality. And we find that consistency at all levels of diversity – both when comparing hyraxes and gibbons, and when comparing different species of gibbons themselves. Siamang, by far the largest species of gibbon, feed most of the time on leaves, and rely less on fruit – they defend their territory less, and their song is correspondingly much simpler. Song complexity certainly has some link to how important it is to defend your territory.

45. The syntax diagram for the hyrax, taken from the numbers given in the previous chapter.

46. The syntax diagram for a lar gibbon song.3

If the only thing that was important in the evolution of language were the complexity of territorial song, then we’d expect many more species to have the kind of impressive communication that we see in lar gibbons. Birds, after all, sing complex territorial song, sometimes just as complex as gibbons, if not more so. Another ingredient is clearly necessary to evolve from the undoubted complexity we hear in blackbirds and mockingbirds to the kind of vocal gymnastics that can support language. Gibbons have something that blackbirds and hyraxes don’t – and that is complex cognition, and a brain capable of interpreting and making sophisticated inferences about the world around them. As we’ll see, combining the ability to say things with a brain that has something worth saying – that’s a key innovation. That’s why primates are special.

Researchers studying wild gibbons have seen clear patterns in the way that they forage between trees. Those trees that are productive and have the best fruit are visited most frequently. Now, that might not sound like such a big deal: plenty of birds have an excellent memory for food sources, and birds such as the black-capped chickadee, a tiny, seed-eating bird from North America, can remember hundreds of different locations where it has hidden pine kernels. But then, navigating in the jungle is quite a complex challenge – just try going into the jungle yourself, and finding your way back to one specific tree in a radius of hundreds of metres. More importantly, navigating fruiting trees means remembering changes in time, not just space. Which fruit were almost ripe last week, and might be ready today? Which trees had overripe fruit yesterday, and might be rotten today? So gibbons, like many primates, make use of their group structure to forage efficiently in the challenges of the jungle. Multiple animals living together means that the group can draw upon multiple experiences and memories – it’s not just one brain remembering where the best trees are. The group structure also enables those rare fruiting trees to be monopolized and defended against other animals, and of course, there are also many pairs of eyes open to spot possible predators. Living in a group suits the gibbon habitat well. And if you live in a group, you need to communicate to other members of your group where today’s foraging is, in a way that a seed-hiding chickadee doesn’t.

All in all, there’s a perfect storm of conditions here: an intellectually challenging environment, a need to cooperate in groups and to defend precious resources, combined with a physical body that has evolved over millions of years some of the key traits for a great leap forward in the ability to communicate. Although these key traits – large eyes, large brains, long fingers – didn’t evolve with the aim of facilitating the evolution of language, they placed the primates in a very special position by making them both intelligent and communicative.

The obvious next step is to use that communicative ability to leverage the intelligence. To talk about something, rather than just say something.

Alarm calls: the clearest of messages (‘Get out of here!’)

We’ve seen that gibbon song is complex for the same reasons that hyrax song and birdsong are complex: it advertises how fit individuals are, and also how well bonded a pair is. But complexity in singing has opened a door to information. The animals could – at least in theory – place specific meanings into their songs. We saw in the last chapter that there is far more capacity for information and meaning in animal songs than could possibly be exploited: billions upon billions of different combinations are possible. But the fact that such variation is possible is a far cry from using it for communication. In evolution, each small innovation needs to provide a concrete advantage – however small the innovative step might be, it must give something that is advantageous compared with the animal that lacks that innovation. What innovation, then, might give an advantage to using different songs for different meanings?

Well, one answer springs to mind: animals could use different songs to indicate important differences in their situations. For example, ‘all clear’ vs ‘emergency!’ In fact, many animals do just this. In Chapter 2, I mentioned how meerkats have a simple contact call that they make constantly to reassure everyone that everything is OK, and they also have a loud alarm call if danger is spotted. Similar communication is found in birds, primates, rodents – it’s a very widespread behaviour. However, what’s important is that alarm calls and contact calls sound very different from each other. You definitely don’t want to confuse the two: and end up happily coming out of your burrow just as the coyote pounces on you. So, there are acoustic constraints on how many kinds of calls animals can make: if they’re going to mean something different, they need to sound very different. Although some animals – including a species of ground squirrel called a prairie dog, several bird species such as jays, and a few monkeys including vervets – have different alarm calls for different predator threats, this repertoire will always be limited. I can have different calls for ‘snake’ and ‘leopard’, but they must sound very different, and if I keep adding more and more predator types, I’ll run out of different-sounding calls. Keeping clearly different sounds for clearly different meanings is a dead-end for complex communication.

Could animals use the huge diversity of potential combinations of sounds to express a wider range of meanings? That is, in fact, what we humans do – we have a large repertoire (tens if not hundreds of thousands of words), and a complex grammar to give subtle (or not so subtle) differences of meaning depending on the way we combine that vocabulary. But our brains are huge – they need to be, to cope with such complex processing and such complex ideas. An animal without such a large brain would not be able to remember that ‘There’s a snake behind you!’ is different from ‘There’s a leopard above you!’ No, animals with simpler brains than ours can’t be expected to make use of the same complex rules that we use to encode information. What else is available to them?

I imagine that one of the things the reader has picked up on throughout this book is how terribly difficult it is to investigate what animals really mean. The wild is a difficult place to do controlled scientific experiments. Every day, the surroundings are different. Animals don’t cooperate – or maybe they’re not even there when you want to do an experiment. If they are, you often don’t even know whether it’s the same animals you were observing yesterday. Although some experiments can be done on animals in captivity, that hardly recreates the real-world scenarios to which the animals have evolved. Still, we scientists do the best we can, and try to devise clever experiments. One of the few ways we can really probe into what animals are saying is to present them with different situations, and analyse the sounds and behaviours they produce in response. This is easiest with alarm calls, because they are far more reliable than other social communication – you’d expect an animal to respond immediately and reliably if it sees a predator. Of course, threatening an endangered species with a live tiger isn’t an ethical way to go about researching communication, so scientists make do with the best alternative: toy stuffed animals. It may sound ridiculous, researchers crawling through the jungle, shaking little model snakes at gibbons, but that’s how things are done. True, these days there’s also the option of animatronic robot snakes and leopards, but the old-fashioned method works too. And once you can elicit alarm calls from the animals, it should, in theory, be a straightforward task to see whether they respond consistently with different calls for different predators. In practice, however, it’s a little harder.

Lar gibbons certainly give different types of calls when presented with different model predators. That’s not so unusual – as I mentioned previously, predator-specific alarm calls have been observed in several species. But gibbons don’t give the same call each time when they see a particular type of predator. In fact, the gibbon response to a predator is quite different and unique each time – and yet it is still possible to distinguish a leopard alarm call from a snake alarm call. Here is an example of each using the letter equivalents shown previously:

Leopard: VVVVVVZSTSTSTSTVSSTSTV

Snake: VVVVZFVVHVVZVFVVVVVVVVVHI

Just as with the hyraxes – a point I don’t want you to overlook – every individual call is going to be different. No one leopard alarm call is going to be exactly like another leopard alarm call, just as no one hyrax song is just like another song (except for short songs where there’s less flexibility). But even though no two calls are the same, there are still clear differences between the leopard calls and the snake calls. Listening gibbons can distinguish between the two, even if no two leopard alarms are the same. Where, then, does the information ‘leopard’ or ‘snake’ lie? Just how can a listening gibbon decide from which predator the threat is coming? One way is the selection of notes used in the calls: lots of T and S in the leopard alarm, but F and Z in the snake call. But the complexity of the gibbon song also shows us an interesting alternative possibility for where the information on predator type might lie. Songs are varied in the way that they move from one note to another – i.e. in their transitions. That means that there’s difference in the syntax. In the quote I gave earlier in this chapter, Charles Darwin speculated that the origins of language might lie in music, as exemplified by the songs of gibbons. We don’t know whether this is any more than a fanciful evolutionary explanation, but it is worth pausing to consider for a moment. Different (human) songs have a different ‘feel’. You don’t need a large and complex brain to distinguish between ‘At Last’ by Etta James, and ‘Anarchy in the UK’ by the Sex Pistols. Indeed, in our experiments with dolphins in Tenerife, we found them very interested in ‘Breaking the Law’ by Judas Priest but totally indifferent to ‘Happy New Year’ by ABBA. Communicating different distinct and unique concepts doesn’t necessarily mean having distinct and unique signals. You can send clear messages by singing different songs that feel different. And that appears to be precisely what gibbons do.

Note that it is the song complexity that gives gibbon song the ability to encapsulate so much meaning in the mere feel of their songs. A simple song, repetitive and unvarying, wouldn’t provide flexibility. It’s true that in a species with a series of highly stereotyped songs – each song type exactly the same when repeated, but very different from each other song type – would have a mechanism for conveying lots of different meanings. ‘Tweet-tweet-chirp’ could mean something very different from ‘Chirpy-chirpy-cheep-cheep’.fn1 But such a mechanism for encoding information is unlikely to evolve. A one-to-one relationship between a sound (or sequence of sounds) and a meaning is an easy concept for us humans to understand, but only because we already have a language. An animal would need an understanding of that one-to-one relationship in advance, and it’s not clear why such an understanding should pop into existence on its own – except in the rather extreme case of predator warning calls. Far easier to understand are the different emotions and responses generated by songs with different kinds of traditions: the strong melody of sixties pop vs the repetitive chord rotation in seventies punk. For gibbons, a particular sequence of notes doesn’t ‘mean’ something in the same way that a sentence in English means something, but it does have meaning. Meaning is just a bit more spongy for animals.

47. Diagrams showing the transitions between different chords in two very different kinds of music: pop songs on the left, punk rock on the right. Nodes represent different kinds of chords, and the width of the lines indicates the probability of each transition, but I’ve left out the numbers for clarity.

Another clue to how meaning might arise in complex songs comes when we compare the transition diagrams for gibbon responses to different toy models of predators. If you look at the diagrams shown for three different types of predators, you’ll see that each song begins in the same way: a sequence of ‘V’ notes, followed by some ‘Z’ notes, and then some more ‘V’ notes. The song then transitions into a second phase, which is completely different between leopard, snake, and tiger warnings. Finally, the leopard and tiger calls have a concluding sequence, which is absent in response to the snake model. How might we interpret this? If you’re an alert gibbon, and you hear that sequence of Vs and Zs – it doesn’t matter whether it’s VVVVVZZZVV, or VVZZVVVV, or anything similar – you know that something bad is going down. Then, the style of the second phase of song tells you what you need to know: might there be a leopard lurking in the branches, a snake winding its way up the trunk, or a tiger prowling on the ground?

One reason why it’s appealing to suggest that meaning is encoded in the transitions between notes, rather than in specific sequences, is because we can see a clear evolutionary mechanism for how such a situation could arise. Communication, and alarm calls especially, are heavily influenced by an animal’s emotional state. How hungry, how tired, how excited an animal is will affect the kind of sounds it makes. And, of course, how scared. But because your emotional state is never quite the same at any two points in time, if your songs were purely determined by how you were feeling, you wouldn’t expect them to be the same twice. That said, songs you produce when you are especially scared would be expected to be more similar to each other than a scared song would be to a hungry song. Indeed, I mentioned in a previous chapter that the ‘seet’ alarm call given by many birds is clearly related to the level of threat: the more threatening the situation, the more ‘seets’ are repeated. It’s like saying ‘Oh crap, crap, crap!’ Once such variation exists, natural selection can hone the variation into different roles. Animals are at a distinct advantage if they respond in one way to a particular song (e.g. run up a tree if it’s a song in response to a tiger) and in a different way to another song (e.g. move to the edge of a thin branch if it’s a song in response to a leopard). Looking for such evolutionary explanations for the kind of meaning we think might be in animal communication is a much more reliable approach than simply looking for animal sounds that might represent the human concept of words.

48. Transition diagrams for the lar gibbon responses to three different predator models. Different phrases (which could be of variable length) are boxed.4

The nature of complexity

One thing that might strike you when looking at these complex gibbon song diagrams above is that they’re, well, very complex. Do they really need to be? Just how much are gibbons saying and how complex does a song need to be to convey that quantity of information? These are difficult questions, and short of asking a gibbon, it’s hard to be sure. However, we are not completely clueless in this department. There are statistical tests that we can use to analyse the complexity of animal communication and see how likely it is that this complexity is somehow ‘useful’. The basic assumptions go something like as follows.

We know that communication is a costly business – animals spend a lot of time and energy communicating, and the more complex a communication is, the more costly. That’s because a bigger brain is needed, not only to generate novel and complex sounds but also to interpret them, and distinguish between, say, a punk rock song and a love ballad. It sounds easy to us, but that’s because we already have big brains. In evolutionary terms, every innovation has potential benefits, but also potential costs, and only if the balance sheet resolves on the side of the benefits will the innovation persist. This means that animals won’t have complex communication for no reason – their communication will be as complex as it needs to be, but no more so. On the other hand, the more information an animal needs to convey, the more complex their communication must be. Where, then, does the balance lie? Let’s consider songs made up of notes from a simple repertoire: A, B, C, or D. Ignoring the order of the notes for the moment (something to which we’ll return in Chapter 7), it should be clear that if you make a more diverse use of your available four-note repertoire, the songs should be more complex. Here are three example songs, first neatly ordered to keep the same notes together (that illustrates the principle better, even if no animal would sing a song like that), and then below that, in a random order (more like what you’d hear from an animal):

Song #1:

Ordered: A A A A A A A A A A A A A A A A A A A A A A A B B

Random: A A A A A A A B A A A A A A A A A A B A A A A A A

Song #2:

Ordered: A A A A A A A B B B B B B B C C C C C C D D D D D

Random: A C C A C D B C A A B A C D C B B B D B D B A A D

Song #3:

Ordered: A A A A A A A A A A A A B B B B B B C C C C D D D

Random: A B A A A C A B B A B D C D A A B A D A A C C A B

The first song is mostly the note A, although there are a couple of Bs in there too. This is what we’d call a simple song. It’s pretty clear that what the animal is trying to say is A, and not much more or less than that. There simply can’t be much information in this song. The second song is a lot more complex. There are four notes, but they’re seemingly occurring with equal probability, and it is unpredictable which note is going to come next. Whatever the animal is trying to say here, it’s something much more complex than just A. In fact, by giving each note an equal probability, this song contains the most information it’s possible to squeeze into the sequence. So, if I’m a gibbon that needs to convey a complex message, which song should I use? Not the first one, clearly, since there’s no capacity to say all the things I want to say. But evolutionarily, not the second song either, because that one is wastefully complex. If I’ve got a repertoire of four different notes, then it turns out to be inefficient to combine them equally.

Mathematically, the best way to balance complexity and simplicity is something like the third song. If you look closely, you’ll see that there are twelve As, six Bs, four Cs, and three Ds. That means that the commonest note (A) is twice as common as the second commonest (B). And three times as common as the third commonest (C). And four times as common as the fourth commonest (D). Coincidence? Strangely not. For reasons that seem well supported but aren’t entirely clear, this arrangement – known as Zipf’s Law – is remarkably common. We see Zipf’s Law in the incidence of words in English: ‘the’ is twice as common as ‘of’, and three times as common as ‘and’, etc., all the way down to about word #10,000 (‘barracudas’, depending on how you count it). Now, this would be a mildly convincing coincidence, if it weren’t for the fact that the same rule holds for every other human language. Something more significant seems to be going on here.

While this is such a peculiar finding that sceptics think it might be a statistical artefact, most animal-communication researchers think that Zipf’s Law does reflect that crucial trade-off between simplicity and complexity. If you have very little to say, you may as well repeat the same thing over and over, as in song #1 above. That doesn’t take much brain power at all. If, on the other hand, all you’re interested in is impressing your potential mate with the complexity of your song, then you should sing song #2 – that still doesn’t take too much brain power, because you’re essentially just choosing notes randomly. But if you have a lot to say (as humans indeed do), then you should arrange your symbols (words, or notes) according to Zipf’s Law.

Using Zipf’s Law to probe the songs of gibbons provides a profound result. The theory predicts that a well-balanced complexity should follow the pattern we see in human language, with each step in the rank-order of a word (second-commonest, third-commonest, etc.), being reflected in a corresponding ratio with the commonest word (half as common, a third as common, etc.). This relationship we quantify using a metric called the Zipf coefficient, and if words follow Zipf’s Law exactly, they’ll have a Zipf coefficient of exactly −1. Examining the 300,000 most common words in English gives a Zipf coefficient of −1.02. Not bad. Hyraxes seem to sing more like song #2, falling much further to the extreme of ‘impress my mates with my complexity’, and having a Zipf coefficient of about −0.02. And the lar gibbon, with its complex song, complex transitions, and the seeming ability to talk about different kinds of predators by singing different kinds of songs? The gibbon’s Zipf coefficient is −0.95, very close indeed to that predicted if the animals are optimizing their information content, as in song #3. Whatever is going on, it would be a very strange coincidence indeed if gibbon song just happened to be perfectly balanced in this way.

Does this mean that gibbons have a language? The easiest answer to give is: of course not. Just because an animal’s communication shares some statistical features with human language doesn’t make it an animal language. However we define language, it’s a much higher bar than just the distribution of the different notes. But can we be sure? Not really. It is incredibly difficult to study the way that animals respond to the messages their groupmates send in the wild. When working with rare, isolated, and inaccessible animals like cao vit gibbons, it’s about as much as a human can do to monitor the presence of the animals, let alone observe their detailed behaviour. We’ve seen in previous chapters that parrots at least seem to have the ability to learn and understand human language, and that dolphins may be able to convey complex instructions to other individuals. Can we be sure that, in the wild, these animals are not using language in a similar way to us?

All the same, we don’t think that gibbons and parrots and dolphins have their own languages. Even within the impressive complexity of the lar gibbon alarm call sequences, it seems that the animals are leveraging that complexity for very simple purposes. You’d expect the alert phrase of an alarm call to be simple, reliable, and unequivocal. Yet we see at least some variation in those alert phrases. This is a clue that gibbon vocal complexity might be directed at purposes other than true language. However, it does seem to be the case that the complexity of gibbon song is more than just for impressing mates. There is information there – information about predators, for instance, or about the group, or the individual – and the animals seem to have evolved to optimize the complexity of their songs for containing information. We don’t know at which point in the twenty million years since our ancestors diverged from gibbon ancestors this wonderful song evolved. Maybe the earliest gibbons sang, or maybe it’s a relatively recent innovation. But it seems clear that the ape brain – both in our lineage and in that of gibbons – is capable of crafting some really complex communication. The goals of human communication and gibbon communication may be very different, but they could well be based on very similar foundations.

We’ve seen that meaning exists in gibbon song, but it’s not encapsulated in a particular acoustic sequence. This observation is crucial: there is no word for ‘leopard’ in Gibbon. Gibbons, like almost all other animals, don’t use words. In fact, this observation may be the most important one I want to impart to the reader. It’s important because, if we want to understand how animals talk and what animals are saying, we must (in most cases) detach ourselves from the idea that meaning means words. No. Animals can convey meaning – and often quite sophisticated meaning – without a one-to-one relationship between a sound and a meaning. Apart from being important for those of us who want to understand what animals are saying, this observation is important for understanding how human language evolved. Our ancestors – like gibbons today – almost certainly had a complex and sophisticated wordless system of communication. Was this the basis on which language was built? Or is our linguistic ability a pure innovation? This is something we shall explore in the next chapter.

49.

6. Chimpanzee

Who has not sat and watched chimpanzees in a zoo and wondered about how human they appear? Their expressions, their behaviour – they are disturbingly familiar, and yet different. They possess so many traits that we recognize in ourselves, and yet they are clearly unlike us, clearly wild. It can be a disturbing experience to see so much of us in an animal, but it’s an important reminder that we are ourselves not so far removed from the jungle. Just six million years have elapsed since the days of those apes whose descendants include both chimpanzees and us. Chimps are the closest living non-human relatives you and I have. How much do we share, and how much is uniquely human – or, for that matter, uniquely chimp? Scientists and philosophers have long looked to apes to find out what makes us different from all other animals. What do we have that they do not? So many of the traits we prize in humans have turned out not to be uniquely human after all. Chimpanzees make tools: they prepare flexible branches to insert into termite mounds and extract the insects to eat. They have a culture that is transmitted from one group to another: individuals observe the behaviour of others and pick up on new skills such as how to crack open nuts. They even have a sense of fairness: chimpanzees won’t participate in an experiment if they see that the rewards given by the scientists are distributed unfairly. And in the wild they make brutal war on each other, searching out and killing chimpanzees from other groups on sight. That last one we don’t generally hold up as an important human trait, of course, but it is one nevertheless. Still, every one of those supposedly special characteristics of humans is found in chimps as well. How are we different? Is it language?

Chimpanzees are the only species in this book that I have not observed in the wild. Not for want of trying, but the Covid pandemic made the challenges of finding and observing chimpanzees in the jungle even harder. Because of their evolutionary closeness to humans, chimps too can catch Covid-19, and strict quarantine restrictions were in place to prevent any harm caused by the virus spreading through the wild population. Conservation needs trump research needs, and so – as is often the case in science – I have to piece together evidence gathered in less-than-ideal conditions: like observing chimpanzees in captivity. Of course, the behaviours that we see in the zoo are genuine reflections of the natural behaviours you’d expect chimps to display in the jungle – tool making and tool use, social interactions and social signals. But just as we cannot expect wolves in captivity to howl like wolves in the wild, so we should be cautious in interpreting our observations of captive chimpanzees. Fortunately, there has been a wealth of research observing chimps in the wild over the years, including by friends and colleagues of mine, discussions with whom inform a good part of this chapter. What’s more, very much like the African grey parrots that we met previously, chimpanzees have shown some very impressive abilities to learn language-like skills in captivity, and that is a crucial piece of evidence that we must not fail to consider. Our closest relatives are able to learn – at least to some extent – to communicate with us, albeit using sign language or via a computer interface, rather than by speaking. What does this say about the origins and nature of chimpanzee communication in its natural setting? Parrots are also difficult to observe in their natural environment, and we assume – or at least, I have concluded – that notwithstanding their impressive learning and language skills, they are unlikely to be using those skills in the wild. Perhaps this is equally true for our closest relatives, or perhaps chimpanzees really do have a need to communicate complex concepts to each other? Do chimpanzees merely possess some of the underlying infrastructure required for language, or can they really talk?

Who are chimpanzees?

Chimpanzees are special, and not just because they are our closest relatives. They possess a quality that drives and pushes them to communicate – a certain something that gives a clear advantage to those individuals among them who can communicate more clearly, and with more information. Evolution favours complex communication in chimpanzees because of the complex society in which they live. We cannot understand what chimpanzees say without understanding to whom they’re talking and why. It turns out that it’s quite unusual for animals to live in societies that are organized in the complex way that chimp society is organized. In the previous chapter we saw that gibbons – apes just like us and chimpanzees – live in small family groups, where cooperation is natural because your groupmates are also your family and share many of your genes. It’s not at all unusual for animals to live in small family groups. Indeed, the cooperation within extended families is probably how group living first evolved. Alternatively, some other species of animals live in very large groups of much less closely related individuals – think of a herd of zebra, under the control of a single stallion. Or, closer to our own ancestors, some populations of gorillas live under the despotic rule of a single male silverback. Single-male groups tend to evolve when the food that the animals eat is widespread and plentiful: even a strong and powerful male cannot stop all the other males from eating grass – it’s everywhere! In such a situation, the only reproductive advantage that a male can gain is from stopping other males from mating.1 Therefore, if they evolve to live in groups at all, animals that eat food that is widely available tend to evolve into groups with a single adult male.

These two strategies – small family groups and large herds with a single male – are by far the most common group-living strategies. But chimps are different. Chimps feed mostly on fruit (as indeed do gibbons), as well as a little meat, but they can only survive in a large group. Most chimpanzee communities consist of a few tens of individuals – compare that with gibbons, who live in groups of four to eight at most. It’s hard to pin down one reason why chimpanzees need those larger groups, but almost certainly it is related to their large body size (a single fruiting tree is unlikely to provide enough food for a whole chimp family), and the fact that their greater nutritional needs engender a lot of conflict with neighbouring chimpanzees. As with wolves, much of a chimpanzee’s day is spent patrolling territory boundaries, looking for possible intruders from rival groups. Because they need so much food, members of the group don’t stay together all the time, but split up, sometimes for days or weeks, and then reunite, rather as dolphins do. In such a situation, keeping all the females to yourself just doesn’t work. For one thing, each group needs an army of strong males to fight border conflicts, and with lots of males around there will always be opportunities for many of them to mate with the females. All this results in a complex dominance structure, in which males compete: for access to females; for access to fruit; for access to the best sleeping sites. It’s true that one male holds a nominal status of the ‘dominant’ male, but unlike a zebra stallion, this title does not provide despotic authority. Luckily for him, the dominant male does mate more often than other males, but when a female becomes receptive, there are certainly opportunities for other males to mate with her. The dominant male will try to stop others from doing so, but he can’t be everywhere at once. To complicate matters, being a dominant male is a precarious position. The authority of the lone stallion in a herd of zebra, or the dominant hyrax sitting on top of his rock, is precarious enough – as with human dictators, there’s always the risk that someone will come and depose him. But for animals like chimpanzees that must live all day every day within a troop of powerful rivals, the position of ‘dominant’ can be maintained only via a complex set of alliances with other strong males. No one individual is strong enough to resist an uprising by several subordinate males.

As a result, chimps are extremely political animals. They coax and cajole others into siding with them in a conflict. They keep an eye out for who is fighting with whom – and intervene if it seems that intervening will improve their own status. For instance, a powerful subordinate male might step into a fight to support a more subordinate individual if he feels that doing so will enable him to count on that individual’s help in a future bid for the top job. Chimps even manipulate the relationships between other chimps to prevent them forming coalitions that are too powerful. A dominant male who sees subordinates becoming too friendly with each other might make a special effort to befriend one of them before an axis against him can form. Imagine how much social cognition is necessary to plan this kind of behaviour. Sometimes a dominant male will even repeatedly switch support between two rivals to keep them both down. Perhaps you recognize much of our own manipulative behaviour in chimpanzees. And these complex political intrigues require communication to make them work.

Gestures and sounds

If you watch chimpanzees interacting next time you go to the zoo, one thing you’ll notice is how much attention they pay to each other. It’s sometimes very hard for a human to notice those subtle signals by which the chimpanzees receive information from each other about what’s going on, but everyone has one eye out for everyone else. If one chimp gets up and saunters off to another part of the enclosure, the other animals need to assess whether he was just bored and wanted to stretch his legs, or whether he spotted an interesting toy or food item that he wants to hide from everyone else. Chimpanzee communication is very visual and can be very subtle. Male chimps can sometimes show sudden fits of anger; they can set upon a rival heedless of who gets in the way, and their flying fists and brutal bites can be dangerous, especially to smaller individuals. It’s always good to be aware if trouble is about to start, and mothers with young babies are particularly careful to avoid getting caught up in any altercation. These kinds of cues are heightened in a competitive, group-living species such as chimps in a way that just isn’t necessary in a cosy family unit of gibbons, who aren’t as prone to the kind of disruption reminiscent of a Saturday night pub brawl. You might catch gorillas lazing around, having a snooze while surrounded by the rest of their troop; that kind of security to sleep in peace isn’t available to chimps – they always have one eye open for trouble. Family groups are generally harmonious – larger gatherings are full of tension, so it pays to be aware of social signals.

Chimpanzees certainly do seem to communicate a lot using gestures, some of which are barely noticeable while others are blatantly obvious. The act of holding out a hand, palm upwards, is a begging signal in chimps, just as it is in humans. In fact, watching chimps holding out their hand when a keeper throws treats into the enclosure might make you think they have been trained to behave in this way – but no, it’s a natural gesture, used in the wild as well as in captivity. Perhaps the most common form of non-vocal communication in chimps is grooming. These animals spend an inordinate amount of time combing through each other’s fur, much more so than what we see in other species of primates. Although the origin of grooming is certainly in the benefit of removing parasites like ticks and fleas, chimpanzees have taken the basic grooming behaviour and modified it almost beyond recognition into what is primarily a social activity. Whom you groom, and when, and how, conveys a great deal of information about what social interactions are taking place. Is a dominant male recruiting allies? Is a subordinate male apologizing for offending a more senior one? Is a male trying to persuade a female to mate with him? Understanding how chimpanzees convey important information about their status and their relationships means understanding their gestures and their visual communication. The complexity of chimpanzee gestural communication clearly tells us a lot about their intelligence, and about how much their social system drives their need to communicate, but it is a very different medium from the sounds and vocalizations we’ve looked at in previous chapters. How important are vocalizations to chimps? How much do they say?

Chimpanzees do make a lot of different sounds, and their sounds do convey distinct meanings. Primatologist Jane Goodall listed almost thirty different vocalizations and their associated contexts from observing wild chimpanzees in Tanzania. Many of these are clearly to do with social relationships, like the waa-bark that is a sign of dominance and the pant-grunt that is a sign of submission. Some sounds, like laughter, seem to be a spontaneous response to tickling or playing. Others are alarm calls, which may or may not be specific to the kind of predator that is threatening the group. The most famous and best-studied chimpanzee vocalization is the pant-hoot, a loud and complex sound that travels long distances through the jungle, and almost certainly has a role like the wolf howl: maintaining contact with members of your group, and at the same time advertising your territory, and probably also your individual identity. Pant-hoots begin with a rather sedate set of ‘oooh’ sounds, not unlike the kind of sounds you’d expect a human child to make if you were to ask them to imitate a chimpanzee. But this phase then gives way to a raucous, screeching set of screams that can be heard from more than a mile away. After that, the animal returns to a more relaxed sequence of notes, almost to relieve the tensions of their screaming climax. Such a complex sequence of sounds, with multiple phases, can vary between individuals, and between contexts, and – presumably – could contain some rather complex information.

50. Example of a chimpanzee pant-hoot.

So far, however, you might be feeling a little disappointed. Here they are, our closest relatives. What’s so great about their communication? Sure, they have complex long-distance calls – but so do wolves. They laugh when you tickle them – big deal. They have a call they make when they’re angry, and a different one when someone’s angry at them – who doesn’t? But can they name objects, as dolphins can? Do they combine their calls into complex sequences like the smaller-brained gibbon? Where do chimpanzees fit on the spectrum of language ability?

Calls of chimps in the wild

We can get an understanding of how much a chimpanzee can communicate in two ways. Firstly, by looking very closely at the natural sounds that they make, and testing whether they are providing real information about the environment to other chimps. Secondly, we can try to teach chimpanzees to speak, and see what happens.

The jungle is, as we saw in the last chapter, a difficult place to work. Quite apart from the physical challenges of getting around, it’s hard to see what’s going on. Scientists can make things a bit easier by habituating animals to human presence: slowly allowing them to become accustomed to scientists quietly observing them, and not posing any threat. Jane Goodall pioneered this technique with wild chimpanzees in Gombe, Tanzania, in the 1960s. But even in a community of habituated animals, the information you can gather is limited. You might be able to see a few chimps hanging around in a clearing, but there are certainly many others just a couple of trees away, that are hidden from view. It’s a frustrating environment for research, because you can never really be sure that you’re seeing the whole picture.

Of course, the chimps face the same problem. How to know where the dominant male is? Or the receptive female? Or, indeed, where the rest of the group is – maybe they’ve moved off and left you alone at the mercy of chimpanzees from another group. And this is precisely where sound comes in. The visual communication of chimpanzees is refined, subtle, and rich, filling the need for complex social communication in a complex social group. But it only works if two animals are next to each other, and in the jungle, that’s often not the case. Sound, on the other hand, travels easily through the trees, and gives the opportunity to stay in touch with others that might be round the corner. So, you would expect chimpanzees in the wild to use sound quite extensively to convey the kind of social information that is crucial to them but can’t be conveyed by gesture alone.

Unfortunately, chimpanzee vocal communication just isn’t that easy for us to untangle. For one thing, chimpanzee calls, unlike those of gibbons, are not easily broken down into distinct units, like notes. Although I mentioned Jane Goodall’s thirty or so call types, these are rather broad categories, and the actual sound of a call of a particular type varies considerably between individuals, between contexts, and even just from the same individual in the same context making the same call a second time. In Chapter 2 we saw that dolphin calls too are graded, without clear distinctions between call types. But in the case of dolphin whistles, the reason whistles don’t have clear distinctions seems to be something different: dolphin whistles are quite precise, rather pure tones, and the animals have very fine control over exactly how the pitch of the whistle varies. So, the gradation of dolphin whistles may or may not carry in itself intentional information. On the other hand, the variation in chimpanzee sounds is much fuzzier. Is this because chimps have less control over the sounds they make than dolphins do? Perhaps the precise form of their vocalizations is more determined by their emotional state – as they get more excited, the sounds become less and less stable. This seems likely. But is it possible that subtle differences in the chimp sounds actually have meaning?

51. A succession of four chimpanzee barks. They are similar (up and then down in pitch), but really very different in their shape.2

Despite the absurd difficulties of investigating chimpanzees in the wild, there are at least some discoveries that show that perhaps chimp vocal sounds really do convey complex information. It has been known for years that in captive studies, a particular kind of vocalization known as the ‘rough grunt’ sounds quite different when the vocalizing animal has discovered a tasty piece of food as compared to a less desirable morsel. What is more, animals listening to recordings of different kinds of rough grunts responded differently depending on what kind of grunt it was: a tasty bread grunt, or a boring apple grunt.fn1 Since then, the experiment has been repeated several times, with different variations, trying to determine whether this really means that chimpanzees are using subtle differences in their graded calls to impart information about the kind of food available – or whether the chimps simply get more excited about tasty food, and that’s why their calls sound different. Note that in the latter case, it’s perfectly possible for other animals to pick up on those differences in the calls, and interpret them as indicating different kinds of food, even if the vocalizing animal had no intention of sending such a message. We humans too can certainly pick up on unspoken cues from others, such as the bored tone of voice when someone at a party really isn’t interested in what you’re saying, but messaging without intention just doesn’t seem to fit what we understand as ‘talking’.

Fortunately, further investigations with wild chimps uncovered a potentially conclusive finding. Whether or not a chimpanzee made a vocalization indicating the presence of a desirable food item depended on which other chimps were listening. Specifically, high-ranking males were more likely to call excitedly on finding food if there were receptive females in the vicinity – like trying to woo your date with a nice meal. Even more convincing, low-ranking males tended to keep quiet if they found tasty food – they knew that a more dominant animal would take the food away from them if they found it. However, those same low-ranking males would make food calls if one of their close social partners was nearby – someone they trust not to seize the food, and someone with whom they can share the food to their own benefit, perhaps in building an alliance that would raise the status of both. These observations strongly imply that the purpose of the rough grunt is indeed intentional: to attract other animals to come and feed with them, but only those animals they actively want to come and feed with them. In an amusing twist, low-ranking individuals who discovered tasty food that no one else knew about would also call if a very high-ranking male suddenly spotted them with it, perhaps to say, ‘I wasn’t trying to hide this food from you … honestly!’

Hunting in gangs

Apart from their social and political skills, there’s another human-like thing that chimpanzees do. They hunt. The strength, intelligence, and sometimes violence of these animals surprises some people. Chimpanzees are not cute little toy monkeys – despite the popular image. Some British readers may be old enough to remember when TV commercials showed chimps in suits and dresses sitting around a table drinking tea from fine china. The contrast to life for a chimpanzee in the wild couldn’t be greater.

Although chimps sustain themselves primarily on fruit, they do eat meat when they can get it. The termite fishing behaviour that chimpanzees use to extract the small insects from their nests – and eat them – is well documented. But chimps also actively hunt for mammals and birds, their favourite being small colobus monkeys. Chimpanzee hunts are complex affairs, and contrast strongly with the strategies of animals such as wolves. Wolves chase their prey over long distances until the opportunity arises to inflict some damage on the exhausted quarry. In general, different wolves don’t take up different roles in the chase. In contrast, there is some evidence that, when hunting small monkeys, a group of chimpanzees will spread out, surrounding their target, with different chimps taking up very different roles. Some will cover possible avenues of escape, some will station themselves below the prey’s tree, in case it decides to escape on the ground, and others will go to flush out the victim. But although hunts are widespread, they are not very common, and, of course, you never know exactly where a hunt is likely to begin. So, the opportunity to study this activity in detail is limited, and our understanding of chimpanzee hunting strategy is incomplete. It may well be that what appears to us as coordination is just each individual chimp figuring out how best to get a piece of the action. If you see that all avenues for escape except one are covered, of course you’ll place yourself there: maybe the colobus will run straight into your hands! That’s not really coordination. Again, we are stymied by the fact that we can’t just ask the animals what they’re doing.

Do chimps talk to each other when out hunting, as some scientists have suggested? A study in 2022 claimed that chimp hunting parties use bark vocalizations to encourage cooperation. We don’t know exactly how the animals interpret the bark, but it might convey more than just ‘Come along! Time to hunt!’ For one thing, the bark vocalization is used in many different contexts – when seeing a snake, or when travelling, for instance – and the precise sound of the bark is different in each of those contexts. What we perhaps somewhat dismissively call a bark may be, to the chimpanzees, a diverse set of calls, each with its own meaning. In any case, just looking at the acoustics of the bark, we can see that these calls are clearly complex enough to contain information that can distinguish between different situations.

52. Four kinds of bark vocalizations, from four different contexts.3

The scientists who looked at the role of barks in hunting found that the more barking there was in the lead up to a hunt, the more successful the hunt. It’s tempting to imagine that the chimps are actually planning the hunt, but this is, of course, not really necessary – or even likely. It may be that certain important information is conveyed by the pre-hunt barking: identifying the target animal’s location, perhaps. But it’s also possible that a good round of communal barking before a hunt improves the hunters’ performance – not unlike a good team huddle before a football match. From the limited number of hunts studied, though, it doesn’t appear that the chimpanzees are actually coordinating their activities during the course of the hunt, as you might expect in a human hunt: ‘You go to the left of the mammoth, I’ll circle round to the right …’ Once the chase is on, it all looks like a huge free-for-all. Even after the hunt, the meat isn’t shared widely, as it is in wolf kills. Whoever gets the colobus gets the first bite, although a more dominant animal could always come and snatch the prize away from you. It is particularly the lack of food sharing that argues against complex communication in hunting: it’s every chimp for him- or herself, rather than a disciplined operation.

Chimpanzees might coordinate their activities for other goals than just hunting. Stories abound of audacious zoo escapes by chimps working together to outwit their keepers. In his book The Song of the Ape, researcher and zookeeper Andrew Halloran gives an amusing true account of a group of five chimps – the recently deposed dominant male, Higgy, and four of his close associates – escaping from their island by stealing a small boat that had been left unsecured and punting it across the moat like a gondola. It’s an escapade that smacks of intelligence and cooperation – possibly even coordination. How to let the other animals know that the escape is on, how to help each other into the boat, and, of course, how to propel the boat off to freedom. Halloran concludes that ‘there had to be an extremely complex form of communication going on’. From what we understand, though, that’s probably not true. There had to be an extremely complex form of understanding going on, but it doesn’t seem like communication is a necessary ingredient. When Higgy got into the boat, the others who were allied with him may have understood the escape attempt and joined in, but that doesn’t mean that Higgy called to them, explained his plan, or gave them orders. A surprising amount of coordination can occur without communication if the cognition is there to understand what is going on. Pretty much the same thing could be said about chimp hunting expeditions. Yes, the animals are doing something cleverer than the kind of coordination we see in sheep, or fish, or pigeons. But that tells us something about their social cognition, their understanding of the perspectives and intentions of other individuals in the group. Tempting as it may seem to conclude that the chimps were whispering their plans to each other behind the keeper’s back, the ability to cooperate, or even to coordinate, doesn’t necessarily imply that those animals are actually talking to communicate their intentions.

The truth is that scientists are still unsure just how much specific information chimpanzees can convey intentionally. If a team chant improves a hunt’s success, that’s interesting, but I think most people would not consider that as using communication when hunting. However, if a complex communication like the bark is both used when hunting and has the potential to contain complex information, then there’s at least the possibility that such a signal could be used for coordination. At the very least, it’s a scenario for a species with additional cognitive powers to exploit these complex signals to allow more active coordination during hunting – our ancestors, for instance. Did our ancestor, the pre-human Australopithecus, who evolved only about one or two million years after our common ancestor with chimpanzees, use hunting calls in a more sophisticated way than modern chimpanzees? We will never know. Certainly, somewhere along that evolutionary pathway, our ancestors picked up more complex ways to use sounds, whereas their cousins, the ancestors of chimps, did not. But to make use of a wide range of sounds for something as intricate as planning hunting, our ancestors would have needed more powerful brains and more powerful cognitive abilities so that they could learn a wide range of relationships between sounds and meanings. Our ancestors then at some point presumably realized that different combinations of sounds could generate an even greater range of meanings. Can chimpanzees do this? One way to find out is to test and see just how much human language they’re capable of learning.

Teaching chimps to speak human

For almost a hundred years, people have attempted to teach chimpanzees to talk. Early experiments were cute, if ethically questionable. In the 1930s a baby chimpanzee, Gua, was raised as a family member by psychologists Winthrop and Luella Kellogg, together with their human child, Donald. Needless to say, Donald developed human language quite normally (albeit with a tendency to produce some chimp sounds when he was young), whereas Gua showed not the slightest inclination to speak. Although such crude experiments seem almost laughable today, it’s important to remember that so little was known about animal communication in those days that for all the scientists knew, Gua might have grown up to speak English just as well as Donald. If no one tries, no one will know. Chimpanzees had been trained to perform many other human tasks (like riding bicycles and drinking from a teacup), so why not language?

The most important conclusion from Gua’s failure to learn to speak was that perhaps chimpanzees lack the right anatomy to produce human sounds: the muscles, nerves, and bones that have evolved in our ancestors to give us the very impressive sound production flexibility that underlies human speech. Indeed, one of the main (and one of the few) clues that palaeoanthropologists use to answer the question ‘When did our ancestors evolve language?’ is to look at fossils of ancient human ancestors to track the changes in the bones of the throat, and other anatomical innovations. Chimps can make sounds, but they can’t make our kind of sounds – they just don’t have the right machinery.

By the 1960s, new understandings of chimpanzee behaviour were beginning to emerge. Jane Goodall’s revolutionary discoveries were showing scientists just how sophisticated was chimpanzee society, and how sophisticated were the methods that chimps used to communicate with each other. Perhaps inspired by this, in the late 1960s two scientists, Beatrice and Alan Gardner, acquired a young chimpanzee, Washoe, and attempted to raise her as a member of their family, but instead of teaching her to communicate with sounds as with Gua, they exclusively taught her human sign language. We knew by this time that chimpanzee communication in the wild is largely visual communication. Mediating the complex social structures and relationships of a chimpanzee troop involves a lot of attention to the subtle gestures and body language of others, as well as to visual displays like shaking branches and stomping around looking angry. The vocal communication we’ve been talking about is a longer-range signal, which doesn’t make it any less important, but perhaps means that it is a channel that is less refined, less subtle. You can shout out ‘There’s food over here!’ but shouting through the jungle ‘I love you!’ seems somehow less helpful. With the richness of natural language, but with no need for complex organs (other than hands), American Sign Language seemed the perfect channel for human–chimpanzee communication. Hopes of teaching chimpanzees to communicate by signing were initially very high: if the animals are naturally aware of subtle gestural communication, surely they could pick this up easily?

The work with Washoe certainly gave some interesting results. She picked up a wide range of concrete nouns (like ‘ball’, ‘cheese’, and ‘dog’) and verbs (like, ‘go’, ‘close’, and ‘tickle’). She could use these words very appropriately, asking for an object that she wanted, or describing an activity that she wanted to perform. She could also combine the words in meaningful ways (like, ‘you tickle me’). Another thing that a language-understanding individual should be able to do is to grasp the concept that you can refer to something in a general way. If you learn the word for ‘grape’, it means any grape, not just the one on the table. ‘Dog’ means any one of a vast variety of animals, many of which barely resemble each other. Most people – linguists, psychologists, and people in the street – would agree that without this ability, you don’t have language. Washoe probably was able to generalize concepts like ‘dog’ and ‘flower’, and this shows some kind of understanding of the nature of a name as a general label.

After Washoe, in the early 1970s, Sue and Duane Rumbaugh tried a different approach with chimps like Lana and, later, the bonobo Kanzi. Here, instead of allowing the animals to learn human-like languages by being brought up in a human family, Lana and Kanzi learned an artificial language of symbols, or lexigrams, on a computer. Lana had free access in her room to a computer keyboard, on which were engraved complex symbols, each representing a different concept – although she wasn’t, of course, to know this at first. Gradually, she learned the meanings of the different symbols, and could combine them to make meaningful sentences, including requests to have more freedom, like ‘Lana drink this out of room?’

53. Some of the lexigrams used by Lana to represent different concepts.

These are unquestionably impressive achievements. But the Washoe experiments, as with subsequent work with Lana (who died in 2016) and Kanzi (still tapping out his lexigrams to this day) have been bitterly controversial. Work with other apes has come in for even more criticism, especially with Koko the gorilla, of whom it was claimed in the late 1970s by her trainer, Penny Patterson, that she had mastered the use of human sign language and was able to hold complex conversations, famously including one with actor Robin Williams. Some scientists think the language abilities of these animals are entirely bogus, others think they are valid, but irrelevant to the question of what true language is. Still others think that the findings have been subtly misinterpreted. One of the most influential critiques was from a carefully controlled research project, also in the late 1970s, with a chimpanzee named Nim, which concluded that, rather than understanding the combinations of hand signals, the chimps merely combined signs more or less at random until they hit on the correct response. So, although these animals do seem to have the ability to learn words and their meanings, it’s still not clear whether they understand the idea that words can be combined into sentences to describe more complex concepts. When Washoe signed ‘you tickle me’, so critics would say, she understood each of the words – ‘you’, ‘me’, and ‘tickle’, but merely signed them at random until someone excitedly came to tickle her.

So began a vast and ultimately deeply controversial digression on whether animals talk. Linguists, philosophers, psychologists, and animal behaviourists have argued passionately for the last fifty years, backwards and forwards: do ‘educated’ animals such as the chimps Washoe, Lana, and Nim, Kanzi the bonobo and Koko the gorilla have language or not? Linguists can be very strict in what they look for in a true language. For instance, there seems to be a need to distinguish between an agent that does something and an object to which something is done. It’s hard to argue with this, and hard to see how a true language could exist if the speakers don’t distinguish between the doer and the done-to. Other criteria we impose seem less clear-cut. Some claim that in a true language, the speaker must be able to refer to their own emotions and feelings, rather than just talking about the world around them. Language experiments with chimpanzees in captivity have had a hard time demonstrating this kind of expression of the internal mental state of the animal. But this is an example where some of the critics among linguists have gone too far. We already know that chimps apologize in the wild, they comfort each other, and they seek comfort. It is wrong to view the expression of emotions and feelings as a ‘language thing’ – rather, it is a social thing.

Questions about whether or what kind of language animals have, and the criteria necessary for answering those questions, are important, complex, and deep. And I am largely going to ignore them. I am far less interested in a yes/no answer to the existence of animal language, although I recognize that it does have huge bearing on how we view ourselves and our own human uniqueness. More interesting to me are questions such as what does the extent to which animals can be taught to ‘speak’ tell us about their communication in the wild? Who are these animals, and what are they saying to each other? How did that communication evolve? And what does that say about how our own language evolved? As you may have gathered from what we have explored so far in this book, I don’t see a single pass/fail test that separates language-using humans from non-linguistic animals. Rather, I want to know what is it that animals need to say to each other, and how that has affected their ability to learn to communicate with us. Even if you don’t believe that Washoe and Koko really could understand their sign language, the fact that they could to some extent signal their intentions and their desires to humans is still a very important observation.

‘How this world is given to lying!’ (Falstaff, Henry IV, Part I)

There’s one more thing about chimpanzee behaviour that is worth mentioning, because it has a surprising relevance to the question of what kind of cognitive abilities might be necessary for language. Chimps can lie. Well, to be more precise, they can deceive. There are plenty of anecdotes of chimpanzees showing deceptive behaviour both in the wild and in captivity. I’ve already mentioned how, if an individual finds some particularly tasty food, they might choose not to advertise the fact unless the other animals nearby are those with whom they might be prepared to share. More importantly, chimpanzees seem to understand the concept ‘other individuals don’t know the same things that you know’. This is a huge cognitive leap. So huge, in fact, that some people feel it’s close to justifying the label ‘personhood’. Why? Because if you know that others don’t know what you know, then you have a concept of yourself as an individual. This idea of ‘perspective taking’ gives clear advantages when living in a cooperative-competitive society such as that of chimpanzees. There is much to know, and much power in knowledge, and power is what moves you up or down the social ladder. So, knowing what you know and what others don’t know is a big evolutionary advantage.

To test this, scientists typically place one chimp, the ‘observer’, where the animal can see everything that’s going on in an experiment. A second chimp, the ‘subject’, is introduced into an enclosure with two boxes. A human comes and places food in one of the boxes. Now a screen is lowered, so that the subject can’t see what’s going on, and the human sneakily moves the food from one box to the other. All the time, the observer can see what’s happening, and has seen the scientist’s duplicitous behaviour (what moral judgement the observer makes on these scientists, tricking the other chimps like that, we don’t know). Now the screen is lifted, and the subject allowed to approach the boxes. Where do they go? Straight to the empty box, of course. They don’t know the food has been moved. How does the observer react? If the observer has no sense of themselves as an individual and cannot distinguish between ‘me’ and ‘you’, then they will be shocked. ‘The fool went to the wrong box! How could they not know that?’ Having seen the food being moved, the observer assumes the subject knows that too. But if chimpanzees do know that ‘what I know is not necessarily what others know’, in other words, if they know that there’s a ‘me’ and a ‘not me’, then they shouldn’t be surprised at the subject’s reaction: ‘Of course they were fooled – they didn’t see the food being moved!’ Scientists can measure the level of the observer’s surprise in sophisticated ways, for instance by tracking their eye movements. If any of you have seen the dramatic Mexican standoff at the climax of the film The Good, the Bad and the Ugly, you’ll know exactly what I mean. And, unsurprisingly, it turns out that chimps do have a perception that what they know is not necessarily what others know.

And it’s not just about food. Frans de Waal, in his book Chimpanzee Politics, describes a junior male, hoping to mate with a female, who suddenly spots the dominant male approaching … His response? Quickly, and almost comically, he covers his erect penis with his hands. Two friends can be grooming each other, but when the dominant male walks by they will jump up and turn their backs on each other – you can almost imagine them whistling innocently to say, ‘I wasn’t doing anything!’ Why is such slapstick comedy relevant to our story? Because if you don’t know that others have a different perspective on the world from you, the most you can do is communicate how you feel. ‘I’m hungry!’ or ‘Stay away!’ If, on the other hand, you know that others know less than you, or at least know different things from you, then intentional communication of specific ideas becomes possible. ‘Go to the other box, you fool – the food is in there!’ Or, ‘No, honest, guv, I wasn’t hitting on her …’ Both of which are communicative expressions that we can imagine being useful in this maelstrom of relationships that is a chimpanzee community.

Can there be a chimp dictionary?

Are we closer to understanding how similar or not chimpanzee communication is to language, though? Of course, it could be that our rigid tests for what language really is – things like syntax, and sentence structure, and agents vs objects – merely reflect tests for what human language is. Critics make a big deal of the fact that Washoe didn’t generalize sentence structure in the way that young human children do. In fact, Washoe didn’t seem to grasp the concept that word order has relevance to the meaning of a sentence. Is that because she didn’t have one of the prerequisites of language – or just that she didn’t have one of the prerequisites of our language? Clearly, human children have an innate propensity for using human grammar, so are we applying a fair test to the chimps? Maybe chimpanzees are doing their own thing. Maybe they have their own language, and we are just too blind to see it?

It’s a common claim, but a flawed one. It’s easy to suggest the possible existence of something that can never be unequivocally disproven – fairies, for instance. But it’s ultimately unhelpful and tells us little about the animals themselves. Decades of studying chimpanzees in the wild, from Jane Goodall in the 1960s up to a new generation of scientists today, including some of my own students, have accumulated years and years of observations of chimp behaviour and chimp communication. The overall impression is that these are animals that communicate rather like other primates do. And, well, primates communicate rather like other mammals do. What we see when we observe chimpanzees communicating in the wild – threatening each other, consoling each other, asking for and sharing food, learning new skills, or even cooperating to hunt or to defend their group – looks just like any non-human animal communication: in many ways more complex than that of other mammals, but essentially of the same nature. Chimpanzees communicate rather like the other animals we’ve met so far in this book – and that’s surprising, given how diverse those animals are. There is no evidence of chimps using language in the wild that is so outstandingly different that we wouldn’t recognize it. Despite the sophistication in their cognition and even in their repertoire, the sounds that chimps make are often instinctive. In one incident, retold to me by a colleague, the dominant male was resting, not paying too much attention to the meat he was hoarding. A young female began to sneak up on him, hoping to snatch a little bit of food unnoticed. As she got closer and closer, her lip began to tremble – she was clearly struggling to control the urge to vocalize. Then, at the last minute, she could stand it no longer, and gave a loud rough grunt: a food call. Of course, the male jumped up and snatched back the meat. Sometimes the sounds just have to come out. In some ways – but not necessarily in all ways – chimps are instinctive communicators like other animals.

Nonetheless, chimpanzees do have some adaptations that give them this special ability to learn human sign language or lexigrams in a way that no species other than those African grey parrots have done. This implies that chimps have some adaptations for language, and very possibly they have inherited those adaptations from our common ancestor. In which case, perhaps the first humans who began to speak as we do, did so on the basis of mental and cognitive skills that are shared by modern chimpanzees. What might those adaptations be, and what clues for them can we find in chimp behaviour?

Halloran, in his book The Song of the Ape, gives a dictionary of nineteen different chimpanzee sounds. Different meanings like, ‘Hallelujah!’, ‘I need help’, and ‘Come here’. Each one associated with a very specific vocalization. It’s a bold idea. Does it take us in a useful direction? Partly yes, because it does show the kind of specific information that chimps communicate to each other. It’s important to understand that these are animals that really are capable of informing their friends and enemies of what they want, what they’re doing, and what they want others to do. But also no, because it leans too much towards the idea of language as understood by humans. Even using the word ‘dictionary’ implies that there is a one-to-one relationship between a particular sound and a particular meaning. Most often in animals, there isn’t. A certain vocalization may tend to elicit a certain response – and such a finding usually has animal behaviour researchers jumping up and down with excitement. Not many animals have even that level of specificity. But it’s still a long way from saying that a certain vocalization means something. And in the end, a communication that is restricted to a discrete set of words isn’t much of a language. If you can’t create new meanings by combining words, then the total number of concepts you can express is just the number of words you have.

Cat Hobaiter, one of the leading authorities on chimpanzee communication, has recently, together with researcher Kirsty Graham, compiled a dictionary of nearly ninety chimp and bonobo gestures, called BonoboBOT,4 although this is more properly a lexicon rather than a dictionary, because they – quite rightly – don’t attach specific meanings to each gesture. Rather, it comprises a suite of signals that undoubtedly convey information, even if that information is often a little equivocal. The extent to which chimpanzees combine such gestures in varied and complex ways to convey varied and complex ideas is far from clear. However, the human language experiments with Washoe and Nim and others seem to imply that the answer is, ‘not much’. There is a great deal of social investigation and manipulation that can be done with a limited lexicon, and it would seem that, for chimpanzees, that’s pretty much good enough.

Halloran also goes to great lengths to distance himself from the somewhat trivial comparison of chimpanzee communication to human language. In comparison to Koko the gorilla, who was trained to appear from the outside to be talking, what we really want to see is how the apes are talking from the inside. As Halloran says:

Even if, during that internet chat, Koko had spoken eloquently and in fluent human language it would have paled in comparison to watching these chimps actually communicate with each other on their own terms … Every moment we spend trying to turn chimpanzees into lesser versions of humans are moments we miss watching how amazing these animals are on their own terms.

So, what is going on with these most human-like animals? They can learn to communicate with us in words and sentences – but not quite sentences as we know them. They build networks of relationships no less complex than our own. They hunt cooperatively, attack their enemies with stealthy commando missions, and throughout this all, use only a handful of sounds. They seem to have a good basis for evolving a language: brains, society, and sounds. But they don’t really have a language – or if they do, they’re hiding it very well. Chimps could use their communication to coordinate their hunts – they seem to have the communicative capacity – but they don’t. Parrots have a similar ability, but it’s much less clear to us what on earth a talking parrot would use this ability for in the wild. Chimpanzees seem to stand to gain a lot from talking. If we left the world for a million years and came back, would we find Planet of the Apes-like talking chimps? Are they on their way to having language?

No, not really. The common ancestors of chimps and humans probably had similar abilities to what we see in chimpanzees today. Advanced brains, complex societies, and just enough communicative flexibility to support the complexity of their niche. Some of the descendants of those ancestors evolved into a niche where cooperative hunting was very important, and some of them evolved into a niche where meat was only a very small part of their diet. One lineage evolved language, one didn’t. One set of offspring exploited the human niche, the other set found jungle living advantageous. Chimps aren’t lesser humans. They are very well adapted to their way of life, thank you very much, and to be honest, most of us would struggle to last a week in a chimpanzee society. Or even a day. It certainly is interesting – if it is true – that the communicative abilities of modern chimpanzees are similar to the abilities of our common ancestor of six million years ago. We can’t know for sure. Probably chimpanzees today exploit a somewhat different niche from our shared multi-great-grandparents, and so their communication is somewhat different. But it is a genuinely helpful way to remember how to think about animal language. They have what they need: no more, no less. No matter how similar to us, their communication is not like ours – it’s precisely like theirs. As it should be.

54.

7. Human (you)

What a piece of work is a man! How noble in reason? How infinite in faculty? In form and moving, how express and admirable? In action, how like an angel? In apprehension, how like a god! The beauty of the world, the paragon of animals …

Hamlet, Act 2, Scene 2

‘The paragon of animals.’ Is that really what we are? Certainly, it is a widely held belief (among humans at least), even if Shakespeare’s Hamlet was being tongue in cheek.

‘… Infinite in faculty’? Well, whether you are a cynic or an optimist regarding the human condition in general, there is some truth in the matter. We humans have language, and an open-ended language at that: capable of saying anything that has ever been said, and anything that ever could be said. Even probing the most intelligent, most talkative animals in the world, as we have done in the previous chapters, we haven’t found in any of them anything similar to human language. I have so far avoided giving a formal definition of language, but I’ve hinted that, in my opinion, language must be something infinite. Or more precisely, infinite in faculty. A language isn’t a language if it can’t say essentially anything that is possible. With just a handful of words, but armed with the power of syntax, we can combine our meagre vocabulary to create soaring novels of fiction, incisive political polemic, and precise scientific treatises. Whatever dolphins can or can’t say to each other, we don’t believe that they can create plays or recite soliloquies. We can. We seem to be qualitatively different from every other animal.

And yet nothing is ever quite as simple as it seems. In looking at wolves, dolphins, parrots, hyraxes, gibbons, and chimpanzees, we’ve seen many things that we can do but they cannot. Yet also, we have many traits in common. Animals can convey emotion, can name each other, combine sounds in complex ways, sometimes with complex meanings, even hold an intelligible conversation with a human. We humans seem desperate to find a clear demarcation line between ourselves and other animals, and the ability to speak language appears to be the most promising and most robust: the acid test of being human or not being human. It used to be accepted wisdom that humans were the only animals to use tools. Our ancestor Homo habilis, once thought to be the first creature to create stone tools like axes and knives, was so named because in Latin Homo habilis means ‘handyman’. And yet, we now know that other animals use tools as well. When Jane Goodall observed chimpanzees in Tanzania using sticks to fish termites out of their nests,1 her adviser Louis Leakey famously said, ‘Now we must redefine tool, redefine man, or accept chimpanzees as human.’ Perhaps language too isn’t quite as clear-cut a distinction as we would like between what is human and what is not human? Perhaps our language isn’t quite all it’s cracked up to be.

While studying gibbons in Vietnam, my two English-speaking colleagues and I lived for two weeks in a shack in the jungle, hours from the nearest village, with six local conservation rangers who spoke not a word of English. We spoke no Vietnamese, and our knowledge of the vernacular, the local Tay tribal language, was limited to ritual drinking toasts: ‘Cheers!’ ‘Your good health!’ ‘Drink up!’ And yet we managed. Naturally, we managed simple day-to-day cooperative activities like sharing a floor on which to sleep, and preparing and eating food. We also navigated social interactions, like offering each other, with bleary-eyed resignation, a glass of sickly sweet coffee when rising at 5 a.m. Or playing complex and obscure gambling games, the rules of which were never explained verbally (if there even were any rules). In many ways, we scientists existed not that differently from a troop of chimpanzees: managing everything from foraging to social interactions with subtle signals that were mutually intelligible, clarifying misunderstandings with exaggerated gestures, and making use of an intuitive understanding of mood, intention, and what the other person was thinking. Our much-vaunted language was laid to one side. Of course, we could never have flown across the world if our ancestors had not had language to cooperate to build aeroplanes, and we still needed to tell the check-in clerk whether we wanted a window or aisle seat, but during much of our social interaction with other humans, language itself largely takes a back seat. Even when we successfully carried out complex data collection with the help of our erstwhile rangers using intricate scientific equipment, pantomime and exaggerated gestures did most of the work. We communicate a great deal without our ‘infinite faculty’, and on the rare occasions when that becomes obvious, then the distinctions between us and our non-human relatives seem to fall away.

How different from other animals are we really? Obviously, we can do lots more ‘stuff’ than they can: to return to Douglas Adams’s observation, we are capable of creating the wheel, New York, and wars. There is no doubt that there is a qualitative difference between our brains and the brains of non-human animals. But is everything all about language?

55. Even when humans share almost no language, we are capable not just of coexisting, but of cooperating, sharing, and even executing complex technological operations.

56.

57.

Time to define language at last?

How can I write a book about communicating with animals, communication between animals, and communication between humans, without actually defining what language is? It’s been an obvious omission up until this point. I must confess, I’m not sure that we can give a clear-cut and universally accepted definition of language, and I’m not sure that we should, but the question is an important one. If language really is the distinction between humans and non-humans, then arguably we’d better be very sure we know what it is.

On the other side of the debate, there are reasons not to bother. We might not be able to do a good job of defining it, for one thing. We must be especially wary if language really is the boundary between humans and non-humans, because a bad definition of a boundary is worse than no definition at all. We might use a strict set of parameters to exclude chimpanzees and dolphins from being human, merely because we want to be unique. Or we might settle for a lax definition and find that we have unsatisfyingly left ourselves with no explanation for why we humans appear to be so different from other animals. And what if no definition can exist? What if, like dolphin whistles, language is merely a spectrum? Something of which some animals have a little (e.g. hyraxes), some have quite a lot (e.g. parrots), and we humans have the maximum amount?

Here, we approach something that we can quantify. Scientists like quantifying things. Perhaps it makes sense to say that ‘languageness’ is a measure of how many concepts an animal can convey. We know that many species – from birds that say ‘seet!’ to primates that say ‘leopard!’ and ‘snake!’ – have a small number of alarm messages that represent specific threats. These animals may be able to convey one, two, or perhaps five different concrete concepts to each other. They have a low level of languageness. On the other hand, dogs can understand several tens of commands like ‘sit’, ‘fetch’, and ‘drop it’. Our close companions, trained to accompany us through life, would seem to have a middling level of languageness, and our determination to communicate with our dogs has demonstrated this ability very well. Then there’s Alex the parrot, who could communicate many, many concepts, perhaps a thousand (perhaps an unlimited number, but I’m going to stop short of that assertion, for illustrative purposes). Alex had a lot of languageness. And us? Being infinite in faculty, we have no limit to the number of concepts we can express. This is full language.

We can imagine a scale of languageness, with humans at the top end, having infinite faculty. We might say that my dog, Darwin, who could understand perhaps 20–30 concepts, had ‘half a language’, and Alex the parrot had 98% language.

It’s an appealing approach – and so practical – although it’s not one that’s grounded in any theoretical foundation, since it’s not clear that such a concept as ‘98% language’ has any real meaning. For one thing, we really don’t know how many concepts most animals can communicate. Even in the case of those that have been intensively studied, such as dolphins, we are still woefully uncertain how much they’re really saying. More importantly, there’s no strong evidence to suggest that our ancestors gradually gained more and more concepts that they could convey, ending up with an unlimited number of concepts. Much more likely is that there was a jump, a rapid leap in brain ability, which took perhaps Homo habilis from being a rather capable communicator to a composer of poetry and a writer of fiction.

58. A scale of languageness, from no language (0%) to full language (100%) can be thought of as corresponding to the number of concepts that can be conveyed.

Looking for the difference between what we humans do to communicate and what other animals do to communicate is a tough challenge. Intuition doesn’t help much. Theory is lacking. One thing we can do, though, is to ask ourselves, ‘What actually happens when we talk to animals?’

The honeyguide: humans and animals cooperating and communicating

Enter one of the most exceptional examples of human–animal communication. The greater honeyguide is a small bird that lives across much of sub-Saharan Africa. Unassuming in appearance, these wild and free-living birds have struck up a remarkable cooperative relationship with humans. Not domesticated, not captive, and not trained, they have learned that humans have the very useful ability to break open beehives, and that humans, indeed, want to do this because we crave the honey that is inside. We humans, however, aren’t very good at finding those hives in the immensity of the grassland savannah, whereas the birds, with little to do every day other than flit around from tree to tree, often spot such delectable reservoirs of delicious grubs that are the young larvae of the bees. And so, as per their name, honeyguides will guide humans to honey. A mutually cooperative relationship has developed between these birds and many of the peoples of east Africa, where a mutually intelligible lexicon has sprung up between guide and guided. Different tribes have developed different whistles and other sounds that have a common meaning, both to human and to bird. Whereas honeyguides have a particular call that means, ‘Come with me! I’ve found a beehive,’ local people also call to the birds when they want to hunt for honey, using a specific combination of trills and grunts. During the hunt itself, both bird and human use specific sounds to keep in contact with each other, so that the honeyguide neither gets too far ahead of the human, nor loses interest in the chase. Once they arrive at a site, the honeyguide gives the ‘Here it is!’ call, and the human happily breaks open the hive, allowing both parties to reap their reward: honey for the humans, and larvae and beeswax for the birds.

59. A honey hunter from the Yao people of Mozambique, with a wild honeyguide bird that has been netted to be tagged.2

This remarkable communicative cooperation between humans and birds raises a lot of questions about how we communicate. How did such an unlikely partnership evolve? Is it the case that humans could speak to each other anyway, and the bird just hitched a ride on our own special ability: not just to understand communication, but also to put ourselves in the minds of another creature – to know that the bird wants us to break open a nest? This understanding of the mental state of another is no trivial thing, and probably an ability that very few other animals share. Perhaps it is actually our own extreme intelligence and mental abilities that underlie the cooperation between human and honeyguide, and the role of the bird is rather trivial and unilluminating? Or perhaps the story goes back further. What if our ancestors, before we gained our infinite faculty of speech, lived in a world full of honeyguides, where humans and animals communicated all the time, just not with language? There’s no doubt that whatever happens between Yao honey hunters and these birds, it’s not a language in any sense that I’ve defined it. There are very few concepts that are conveyed. ‘Let’s hunt.’ ‘Slow down, I can’t fly as fast as you!’ ‘Here’s the hive, break it open for me.’ To other humans, looking from the outside with the benefit of our existing language ability, we can put words on the messages as I’ve done above. Can we ever really know whether the honeyguide thinks of these messages in a similar way, rather than just responding instinctively to the sounds that the honey hunter makes?

Whether or not another animal really understands communicative messages, in the way that we instinctively know that we humans understand words, is a difficult problem to test. We saw in Chapter 3 that parrots probably have the ability to understand true reference, rather than just relying on a consistent association between a particular sound and a particular outcome. It’s quite likely that this ability is rare, but that doesn’t mean that the honeyguide doesn’t possess such a concept of meaning. What would happen if someone tried to train a honeyguide using Pepperberg’s M/R technique that was so successful with Alex the parrot, using social cues to help an animal understand the true meaning of words? Is the number of concepts that a honeyguide can learn heavily restricted by the fundamental lack of processing ability in their small bird brains? It seems that I am posing very many questions that can never be answered – that the animal brain will always be a mystery, compared to the ease with which one human can ask another, ‘What are you thinking right now?’ But it is precisely by looking at those rare cases where humans and animals successfully communicate with each other that we can tease out some clues.

Dogs: our most familiar communication partners

If honeyguides are fascinating but obscure, human–animal communication is familiar to everyone through our relationship with dogs. The rich and often extremely precise interaction between humans and dogs, probably the closest of all such relationships, is both exceptional and routine. There is no other animal with which we communicate so effectively and so broadly. We can ask dogs to seek out contraband and to pull down escaping criminals, to herd sheep precisely and accurately, and to lie on our rug and comfort us when we’re feeling down. Dogs can receive and understand both specific and precise instructions, as well as vague and poorly formed ideas. Do we share a language with dogs? I mentioned earlier that my dog understood maybe a few tens of concepts – hardly an infinite faculty. But this is still many, many times more than anything I could convey to a dolphin or a chimpanzee. It seems unlikely that he understood those concepts in a language-like way, but then, what was he doing when I said, ‘Let’s go for a walk’, and he bounced up full of excitement?fn1

Dogs are, of course, domesticated animals. We humans have spent probably tens of thousands of years selecting and breeding them to suit our requirements, which include both very practical needs such as protecting livestock from predators, as well as subtle ones such as understanding our tone of voice and our intentions as expressed through body language. Although dogs were domesticated from ancestors who were probably quite different from modern wolves, the wolf is the dog’s closest living relative, and so it’s instructive to look at how these two species differ when it comes to interacting with humans. And there do seem to be some very significant differences. Researchers both at the Wolf Science Centre in Vienna, and at the Eötvös Loránd University in Budapest have tried to tease out the fundamental differences between dog and wolf.3 Wolf cubs raised by humans alongside dog puppies are indeed adorable, but by the time they reach maturity, they are utterly unmanageable. Whereas dogs pay attention to the human voice to understand the task that is required of them, wolves seem as if they couldn’t care less about humans. Evolved to live in a pack of peers, wolves just don’t have the – for the sake of simplicity – subservience to humans that domestic dogs do. This is something that we have bred into our companion animals and is quite noticeably absent in their wild relatives. For example, dogs will reliably go to a target when a human points at it, wolves will not – they seem to have little interest in what human fingers are for (except perhaps for nibbling on them). Using complex camera equipment, it is possible to follow the exact direction of an animal’s gaze, and it’s clear that if a human so much as looks at a target, a dog will look at it too. A wolf will not. Dogs are significantly more likely to look at an image of a human face than at an image of something inanimate. It is a well-known generalization that staring into the eyes of an animal is usually interpreted by the animal as an aggressive gesture – and yet the reverse is true for dogs. Dogs want us to look into their eyes, and experiments have shown that making eye contact with a dog increases the levels of pleasure-giving hormones like oxytocin both in the dog and in the human. It’s as if both dog and human are biologically built to communicate with each other – and that is, in fact, the case. Humans have not only domesticated dogs to respond to us, but also domesticated ourselves to rely on dogs. That partnership of 50,000 years works both ways.

Why did we domesticate dogs? No one knows. It seems likely that many things were happening at the same time. Perhaps our ancestors merely tolerated the less savage of the scavengers that frequented the rubbish piles of early human settlements – such a relative toleration is enough to set the process of domestication in play. Perhaps our ancestors realized that having a pack of feral scavengers around the settlement brought the added benefit of alerting us to the approach of more dangerous predators. In any case, dogs and humans have come to collaborate in more and more complex ways. Clearly, the more complex the collaboration, the more complex the communication needs to be. And yet, despite the disdain with which wild wolves seem to view humans, this collaboration between human and domestic dog is based on a biological predisposition that existed even before any domestication took place. When faced with a cooperative puzzle, wolves will cooperate with humans. A common behavioural experiment is to place a reward in a way that it can only be released when two ends of a rope are pulled simultaneously. If an animal pulls on one end by itself, the rope merely comes free, and the reward can’t be accessed. If another animal (or human) pulls on the other end at the same time, the drawer can be opened, and the reward achieved. Many animals, including birds, primates and elephants, can learn to cooperate with other members of their species to solve this puzzle. Both wolves and dogs will cooperate with humans to do this too. That means that the cooperative ability is very deep indeed – we did not domesticate cooperation per se into dogs. But whereas both wolves and dogs can solve such complex problems, dogs have a tendency to look towards humans when faced with a difficult challenge. Dogs intuitively know we’re likely to help them – we have bred such a knowledge into them. Wolves lack that intuition.

60. Both wolves and dogs will work together to solve a cooperative challenge, in this case, pulling on both ends of a rope to open a drawer. But dogs are less good at the task – they have evolved to rely more on humans to help them solve difficult problems, rather than figuring out the answer for themselves.4

Together with this canine intuition comes prestigious ability. Consider the astonishing behaviour of a herding sheepdog. These animals have been trained not just to respond appropriately to a wide range of signals but also to understand the context (depending on what the sheep are currently doing), and to understand what is required of them. Commands such as ‘Stand!’ and ‘Wait!’ are clear enough, but herding dogs can also understand ‘Look back’ (i.e. ‘You missed a sheep – go get her’), ‘Speak up’ (i.e. ‘Bark at the sheep – they’re not paying enough attention’), and ‘In here’ (i.e. ‘Go through the centre of the herd to divide them into two groups’). It’s fun and impressive to watch these remarkably capable dogs go through their tasks, and in the UK, televised sheepdog competitions have since 1976 attracted a viewing audience of millions. But is it evidence of language? There can be no doubt that the shepherds are talking to their dogs, and the dogs are understanding them, in a more meaningful way than merely responding instinctively to a stimulus, as a horse would when you say ‘Whoa!’ How much can we deduce from these clever animals? If we really do define language as the number of concepts that can be conveyed, then Chaser the Border collie may have been, until his death in 2019, the most language-capable non-human so far encountered. Chaser knew the names of, and could fetch on command, any one of 1,022 different objects whose names he had been taught. I previously plucked out of thin air the number 1,000 as the number of concepts Alex the parrot could convey, but this was merely illustrative – Alex wasn’t tested explicitly on how many concepts he understood. Chaser certainly knew at least 1,022 words. Which of them was more language-competent? We feel intuitively that Alex’s abilities were superior to Chaser’s because he was more flexible – he had fewer words but could combine them in a way that Chaser couldn’t. Yet Chaser had a far wider vocabulary.

It’s difficult to make this rigorous. If we admit a scale of languageness, we have hardly solved any problems at all, because our goal – language as humans speak it – would seem to be out of the grasp of any animal. It’s hard to tell what it is that we observe objectively, and what it is that we want to believe. I know that I certainly want to believe that my dog understands me. But as a scientist, I would much rather put that belief on a firmer footing.

What makes a language?

Another way to firm up our understanding of what language is – so that we can confidently look for evidence of language in animals without denying that we ourselves have something special – is to examine those features of language that are generally thought to be important, and to apply a critical eye. For example, the linguist Charles Hockett in the 1960s decided that there were thirteen criteria that must be met for a communication system to be considered a true language. Some of these we can dismiss as being overly focused on human language, but some certainly deserve more attention. In any case, examining what we think appear to be important properties of our own language gives us insight into what features we should – or shouldn’t – be looking for in other animals.

Hockett’s first criterion is his weakest, and demonstrates the pitfalls of relying too much on comparisons with our own language. Hockett claimed that language must have a ‘vocal-auditory channel’. We can dismiss this right away. Although the use of sound to communicate is a particularly effective route to take, there’s certainly no reason that a language could not be built on (as I mentioned in the introduction) varying electrical fields, as with the electric fishes in the jungle rivers of Africa and South America, or even swirling patterns of colour, as on the skin of a cuttlefish.

Skipping over such physical constraints, Hockett does make some interesting observations. In a true language, the essence of the transmission of a message is independent of the accuracy of that message. Although it may seem that decoupling the content of a message from the real world would make complex communication more difficult rather than less, there is an important point here. A dominant male hyrax can sing a complex song, but a juvenile male can’t. It’s not that he doesn’t want to – he just doesn’t have the ability, and this is not something consistent with a truly flexible language: everyone must be physically capable of using it in the same way.

Some of his criteria such as semanticity (i.e. that words mean things) are deeply rooted in our understanding of the nature of language – this is something that I will discuss in much more detail below.

Displacement would seem to be another thing that is important: we can talk about things that aren’t here. The traffic on the way to work yesterday. My son in Edinburgh. Displacement certainly seems to encapsulate something that humans have and other animals do not, and it’s true that a language where we could only talk about what’s in front of us would provoke a series of rather boring conversations. But this seems to be a feature of cognition, rather than a feature of language itself. We can expect displacement, but shan’t require it.

Three of Hockett’s criteria are widely accepted by linguists, but when we look at animal communication, it causes us to question their universality. Language, claims Hockett, should be ‘discrete’, ‘arbitrary’, and ‘dually patterned’. Discreteness we have come across before: dolphin whistles are graded (i.e. non-discrete). One whistle can merge smoothly into another, and there’s no point at which you can say, ‘This is whistle type one, and this is whistle type two.’ Linguists will refuse to compromise on discreteness in language, and will say that it is actually impossible to generate the infinite faculty that we seek in a communication system that is based on graded signals. For me, as someone who researches meaning in graded dolphin whistles, ‘impossible’ is a very big word. I do agree that language is unlikely to evolve down a route that is based on graded signals, but is it impossible? I think not. Animals work with the systems they have to hand. Our ancestors, rather like modern chimpanzees, had the flexibility of discrete vocal signals and discrete gestures. That certainly made it easy to go on to evolve a language comprising discrete words. If they had been constrained, as dolphins are, to graded signals, perhaps they would never have evolved language. Perhaps that is one of the reasons that so few species on Earth (actually, only one) have done so. Or perhaps, if the need were great enough, they would have found a way to combine graded signals with infinite flexibility. On this, we must admit the jury is still out.

Having words that are arbitrary, i.e. that don’t in themselves reflect the object to which they refer, seems like a good thing in general. At least it means that your vocabulary isn’t restricted to those things that you can evoke with the spoken word, like onomatopoeias. It’s hard to see how you could build a non-arbitrary language that includes words for ‘picnic’, ‘integral calculus’, and ‘spaceship’. So arbitrariness is likely, but it’s certainly possible to imagine a language where words are (mostly) not arbitrary: a pictographic written language such as Egyptian hieroglyphics would be an example.

Duality of patterning is another thing considered by language scientists to be as important as discreteness. In our language, meaningful words are made up of meaningless elements: the different sounds we can make with our mouths. There are rules that dictate how sounds can be strung together, but those rules are constrained by the production of sounds (try saying ‘grkjhx’ – it won’t end well), rather than rules about meaning. Conversely, the way you combine words is to do with meaning, not sound: ‘animal welfare’ is not the same as ‘welfare animal’, and both are well-formed expressions, unlike ‘grkjhx’. Most human languages have a few tens of different meaningless sounds that can be produced. If we couldn’t combine them into words, we’d have only a few tens of possible words that we could make. Instead, most adults have access to a vocabulary of more than 100,000. But is it inconceivable that a language cannot exist where meaning is generated differently? No, our language is constrained to use duality of patterning because we have only a few sounds to make. Dolphin whistles, on the other hand, are far more flexible. If they could bypass the difficulties caused by the lack of discreteness, perhaps duality of patterning wouldn’t be so crucial.

So, examining what makes human language a real language is helpful in some ways, distracting in others. Some properties of human language may be truly universal constraints, some may be peculiar to us. In my book The Zoologist’s Guide to the Galaxy I discussed some ways in which language – and indeed animals – might evolve on other weird and wonderful planets to be something very different from language on Earth. But in this book we are interested in what real animals actually do. Which features are we going to insist must be present if we’re going to say that an animal – right here on planet Earth, not in an imaginary sci-fi world – has language?

There are at least three features that most people would point to and say, ‘Yes, my definition of language is going to require these.’ Two of them are pretty straightforward: the fact that words, however defined, have meaning, and the fact that word order has meaning. The third, the importance of context in defining meaning, will require a little more unpacking.

Words have meaning

In our language, and probably in anything that could be reasonably called a language, symbols – typically words – have specific meanings. In the correct context, dog means dog and cat means cat. We’ve generated huge vocabularies of these relationships between a word and what that word represents, and most scientists would be comfortable with the idea that semantics is absolutely necessary for any kind of communication to be considered a true language. Most ordinary people, too, would be comfortable that they use semantics. We all use words – lots of them – to describe the things we see and feel and want. The idea that there can be a one-to-one relationship between a word and a meaning is natural and intuitive (although there’s also scope for variation in meaning – see the section below on context), and probably just an artefact of how deeply ingrained our word-based language is to us. As we have seen, in animals, things are a bit less clear-cut. Not every species has words, and even where we think some animals have specific sounds for specific concepts – like vervet monkey alarm calls, or dolphin signature whistles – it’s far from clear that this is a one-to-one relationship. I’ve already pointed out that dolphin signature whistles sound slightly different each time. Until we can ask the dolphin, we don’t know whether those sounds really mean one thing, or many things. No one vervet alarm call for ‘leopard!’ sounds quite like another. Somehow, we humans have evolved to be tied into a system where we think only in terms of ‘word equals meaning’. It’s not a bad thing – the sematic relationships that are so dear to us certainly do form a pillar of our own language. But it hampers somewhat our efforts to understand what animals are saying. We feel obliged to assign specific meanings to specific animal sounds. How do chimpanzees live in their complex and ever-changing societies? How do dogs live with our own complex demands, without words? Why are animals so different from us?

One possible explanation is that word meanings actually evolved long after complex communication became commonplace in the societies in which our ancestors lived. It’s almost as if words were an afterthought, an embellishment on communication. Unnecessary glitter attached to the ordinary kind of signals that animals send to each other all the time. Words possibly didn’t provide much advantage to our early ancestors, and still don’t provide advantage to the species we’ve looked at in the last six chapters. In fact, a one-to-one relationship between a sound and a concept could actually be quite a drawback in most kinds of communication that are important to any species apart from humans. It’s no small feat to make a consistent and uniform sound, time after time. Even for humans, learning the correct pronunciation in a second language can take years (or perhaps never be achieved at all). Having words is a lot of effort, and evolution doesn’t favour effort unless it provides a clear advantage to the individual. The process of going from a fluid, malleable signal like a wolf howl or a hyrax song to a rigid, formalized representation of a meaning is one that happens only rarely. When a chimpanzee holds out its hand, palm upward, requesting some food, the precise form of the gesture really doesn’t matter. She could put her right hand out or her left – the meaning is obvious either way. No formal rules are required.

What’s needed is for a sound, or a gesture, to become ritualized. For the same action – exactly the same – to be representative of a particular concept, and of no other concept. In most animal groups, this just doesn’t seem to happen. Many times, the signal itself is too complex to be ritualized. Hyrax song, for instance, varies so much from bout to bout, it’s unlikely that the hyrax himself even knows what notes he just sang a moment ago. Expecting him to repeat a sequence precisely seems unreasonable. Whether ritualization of signals became a fact in our distant ancestors because they needed that reliability to inform each other of specific information, or whether it happened because social interactions in general became ritualized (e.g. if a certain greeting given to a more dominant individual will elicit a particular response), we don’t know. But most other animals live in a non-ritualized world, and so their semantics are nebulous, approximate.

To have clearly defined words also means that you need a very clear and firm concept that you are trying to convey, and it’s likely that animals are less able to generalize concepts compared with humans. Monkeys probably don’t think of ‘leopard’ as a concept in itself, rather, ‘leopard in the tree on the left’ is a different concept from ‘leopard far away on the ground’. This is reminiscent of the much quoted but highly imprecise idea that Inuit and Eskimo languages have hundreds of words for snow.5 What sets humans, both European and Arctic, apart from animals is that we can conceive of a single word for snow. We can make that generalization, just as we learn from picture books that a car can be red, or blue, or even have a smiling face on the front. Although language experiments with animals like Alex the parrot can probe their abilities to generalize such concepts, it is only with the most exceptional of species that we can ask the questions to which we really want answers. For most animals, they will merely look back at us with mild confusion.

Order is meaning

I’ve mentioned in previous chapters that it’s at least possible that distinct sounds can be combined in new orders to give new meanings. If having words were all there was to language, we’d need an infinitely large vocabulary to say all the things we want to say. We’re smart, but we’re not that smart. Brains evolved to be efficient – no animal can survive with such a massive brain that it can remember separate words for every concept that exists. Being able to combine words gives a neat solution: I don’t need separate words for ‘big cat’ and ‘small cat’ – I just need to combine my words for ‘big’ and ‘small’ with my word for ‘cat’ – now I have a system that works equally well for big and small apples, and big and small mountains, and so on. The power that syntax gives is the power for an explosive expansion in the number of concepts you can express. Most linguists, following the lead given by the patriarch of linguistics, Noam Chomsky, would say that our syntactic ability is the crucial innovation that separates us from other animals. We can express any number of concepts; other animals are inherently limited, inherently stunted. Chomsky has been a foundational influence in the development of the field of computational linguistics, but his ideas on the origin of language are somewhat less universally accepted. Indeed, it was Chomsky’s insistence that humans are unique in being born with a language ability that led Herbert Terrence to name the chimp he used for his language-learning experiments ‘Nim Chimpsky’. Some ultra-Chomskians would even claim that a single genetic mutation switched on a special syntactic ability in the brains of our distant ancestors. A single event that, in an instant, converted a non-human into a human by bestowing the gift of language ability – not unlike Michelangelo’s ‘Creation of Adam’ on the ceiling of the Sistine Chapel. The inspiration for that famous scene, with the fingers of God and Adam almost touching, was probably the Latin prayer dextrae Dei tu digitus … sermone ditans guttura, – ‘thou finger of God’s right hand … giving the power of speech’. Even here, the creation of humans is associated with creation of language. For others, this is a hard pill to swallow – surely evolution works gradually, generation by generation of minor improvements, rather than by chance mutations with such dramatic results?

As always, comparing human speech with animal communication is instructive. We looked at syntactic ability in Chapter 4, when considering the unimaginable number of combinations of hyrax song. Yet hyraxes don’t make much use of the potential their syntax gives them. Syntax in its simplest form is widespread – it is the simplest way to make utterances variable and unique. What Chomsky describes is a very special kind of syntax: the ability to make meaningful and distinct combinations that have regular and clearly defined meanings. Do animals ever do that? Some scientists believe that at least some animals probably do, and there are various groups around the world looking for fingerprints of language in animal communication. Some have claimed to have found evidence that starlings, tits, putty-nosed monkeys, or any one of a host of other species, make use of the kind of combinatorial antics that Chomsky felt was unique to humans: what they call (very unhelpfully) the ‘merge operation’. At its simplest level, this merge operation describes the way that human language can embed concepts within concepts, phrases within other phrases. I can say, ‘Nim is going to the shop to buy a banana,’ but I can also say, ‘Nim the chimpanzee, named satirically after a famous linguist who laid the foundation of the field of generative grammar, is going, most likely by bus, to the shop to buy a banana, which is his favourite food.’ Language flows from phrase to phrase, and even within phrases, making more and more new and complex messages possible. If this ability is present in animals, it is present in very few. However, I should warn you here that these ideas are among the more controversial in the field of human and animal communication. If you have a significant other who happens to be a linguist reading this over your shoulder, beware.

We know that we can train certain animals to understand at least some elements of human grammar (you may remember that in Chapter 4 I distinguished ‘grammar’ from ‘syntax’ by the quick and dirty trick of saying that grammar has meaning). Dolphins and chimps and parrots have all shown this ability. Ake the dolphin could distinguish between ‘Bring the ball to the hoop’ and ‘Bring the hoop to the ball’. Lana the chimpanzee probably had a sense of word order, but Washoe the chimp probably didn’t. And Alex the parrot formed correct sentences with uncanny ability. Such an ability hasn’t been found in very many species, although to some extent that is probably because it is extremely hard to train most animals for such complex and unnatural tasks. Perhaps we will find many more. Nonetheless, a conception of the importance of word order seems very rare in animals. Even dogs, our trusty companions, always on hand, always interacting with us, always responding to our requests and commands, have at best the weakest understanding of grammar. Experiments to test whether dogs can understand even the simple combination of two different words, e.g. ‘ball’ + ‘fetch’, are inconclusive and controversial.

Why is grammar so rare in the animal world? Syntax is almost universally present, but rarely contains meaning, and when it does, that meaning is usually arbitrarily related to the actual order of the sounds. Syntax seems to be, at least almost always, an artefact, a coincidence arising from constraints on the way that animals produce sounds, and the way that animals interpret sounds. Animals like hyraxes can understand differences in the order of sounds – that’s natural to their way of life. But it’s of no use actually to construct specific meanings by varying that order intentionally. Indeed, even those animals that can understand human grammar (with a bit of help from human trainers), don’t use anything like that complexity of ordering in the wild. So, it makes sense that the innovation that sets us apart – the finger of the right hand of God – was an innovation in cognition, possibly even nothing at all to do with language itself. Perhaps an innovation more related to understanding the world around us: objects and their relationships to each other, the way they remain permanent, or the way they change with time, and the way objects change when they interact with other objects – ‘Once that chimp has eaten this apple, there won’t be an apple any more.’

One possibility is that we humans had a brainwave about a million years ago and went from understanding syntax – as many animals do – to actually using it. Once we could do that, so many more opportunities for communication opened up, and our brains rapidly evolved to keep up with the ever-multiplying selection of songs and stories, plots and plans (whether to catch prey, or to seize power) that could circulate within our social group. Syntax isn’t that useful – doesn’t become grammar – unless the words have distinct meanings, and so it’s likely that words themselves only came into being after we evolved the ability to perceive meaning in syntax.

So, what does this say about our undoubted ability to communicate with at least some animals? If they don’t have our gifts of words and grammar, how could we even start to hold a conversation with our dog? Herein lies the beauty of the third pillar of language: context.

Context is meaning too

What exactly do animals understand when we talk to them? Our grammar? Unlikely. It doesn’t seem that animals can grasp the intention of our sentences without intensive training. Our words? Maybe. At least partially, and certainly some animals can understand many more words than others. But even if we doubt a particular animal’s ability to distinguish our words, there’s still an uncanny transfer of information and intention. When I asked my dog, ‘Would you like some cheese?’ he invariably showed some understanding. Is this remarkable, or is this trivial? Which words did he understand? Certainly not ‘would’ – a very peculiar word that introduces a possibility in the future and expects an answer indicating intention. Such time-travelling gymnastics is almost certainly beyond a dog’s ability. ‘You’ is also a concept that is difficult for a dog – he knew his name, Darwin, but the concept of a ‘you’ and a ‘me’, i.e. that there is such a thing as individuals that are different, and each one a conscious being, is probably a hazy idea at best for a dog. Similarly, we can argue that in fact, the words ‘like’ and ‘some’ are probably unnecessary too. ‘Some’ is as vague as ‘would’ or ‘you’ – either there is cheese or there isn’t. It’s not clear what actual information the word ‘some’ even adds. It’s true that ‘like’ has some genuine meaning, but is it necessary? Try the sentence without that word: ‘Would you some cheese?’ Even the word ‘like’ seems to be somewhat superfluous. No, the only word that’s necessary here is CHEESE. And strangely, even with what seems to be the core of the question, I’m uncertain just how much a dog understands.

You may have tried this experiment with your own pet: replace the word for something that they like with an arbitrary alternative. ‘Would you like some stones?’ Or ‘Would you like some calculus?’ Chances are the reaction will be the same. The reason isn’t hard to find. Have a look at the spectrogram below. Notice the rising tone of the word ‘cheese’. How did you ask your dog if she’d like some calculus? ‘Would you like some ↗calculus?’ no doubt. It’s almost impossible not to make that rising pitch when mentioning something exciting. Whether or not Darwin really understood the semantics of ‘cheese’ vs ‘walk’ vs ‘calculus’, for sure he understood the excitement of the rising tone. A sentence without that rising tone has a different meaning, for humans as well as for dogs. Same words, same syntax, different meaning. How does that happen?

61. Spectrogram of me asking my dog Darwin if he’d like some cheese.

Language is a lot more than words and sentences. It’s easy to forget the ease with which we communicate silently and subtly with other humans – until you’re stuck in the jungle with no shared vocabulary. A sly wink can be enough to transform the meaning of a sentence by 180°: ‘Sure, we’ll finish work this afternoon instead of going to the pub.’

How do we figure out which of the two possible interpretations is correct: ‘we will conscientiously stay at work as we should’ or ‘we will sneak out and go for a drink while tricking our supervisor into thinking we’re still in the office’? In this case, we use extra information: the wink. One could, I suppose, argue that the wink has a meaning of its own: ‘negate the previous sentence!’ But sometimes, context can be crucial, even without such explicit cues.

Consider the sentence: ‘Yeah, maybe I’ll go to the garden and eat worms.’ Context dictates precisely how we should interpret sentences like this. If you are a parent and your child is angry with you, it’s clear that they don’t actually mean they’re having worms for dinner. If, on the other hand, you are a hunter-gatherer, perhaps the literal interpretation is correct. Irony is a hugely peculiar phenomenon, and one that it is almost impossible to imagine evolving in animals – a communicative statement that means the opposite of what it appears to say. Many different types of context can be important in communication: body language such as winks, shrugs, or frantic waving of the hands; knowing something about the speaker (or the spoken to), their past history and what is on their mind at the moment; or even knowing something about the world we live in.

What about the statement ‘A red apple’? That might seem completely unambiguous. It isn’t. You and I might know what a red apple is: it’s an ordinary apple with red skin. Would someone who’s never seen an apple know this? Definitely not. Perhaps the meaning of ‘a red apple’ is that the apple is red all the way through? Certainly ‘a red plum’ often is.6 Not to mention the possibility that the apple might be in some way associated with communism.fn2 Words and sentences just aren’t enough. We ourselves rely on context to make our statements take one single meaning out of a whole range of possibilities. It’s fun to play with different examples of how sensitive human communication is to small contextual differences. But do animals have a similar kind of sensitivity?

It shouldn’t surprise you that the answer to this question isn’t simple. On the one hand, it seems that animals must rely on context – if they don’t have semantics, what else can they use? Dogs respond to the tone of your voice: rising and excited, or severe and angry. They will also pick up on more general contextual cues: are you standing or sitting? With your arms reaching for the fridge, or crossed over your chest? In their desperate drive to please their human pack mates, every cue is carefully incorporated. But on the other hand, some contextual elements of language appear to be almost exclusively human. So much of contextual communication depends on understanding that the conversation partner is actually thinking something. The real power of context in language is that you can imagine the thoughts in another person’s head. Do they really intend to eat worms? What are they actually thinking? An excellent example7 is the following:

Jane: ‘I’m leaving.’

John: ‘Who is he?’

Perfectly intelligible to any human reading this book, that exchange is nonetheless completely baffling from an external objective perspective. There appears to be no outward connection between the two sentences. What is missing? What’s missing – apart from specific contextual information about the state of the relationship between the two protagonists – is the thought process. When hearing Jane’s comment, John imagines what is going through her head. Only that way can he come to the conclusion that ‘Who is he?’ is an appropriate response. In Chapter 6 we talked about how chimpanzees can lie, because they understand that what they know about the world is not necessarily what other individuals know about the world. They have a sense that there are separate, distinct individuals in their society, each with their own separate, distinct perspective on the world. Such a sense would appear to be exceptionally rare among other animals. Humans can do it extremely well. Chimps and elephants and dolphins seem to be able to as well. A number of other species, including crows and possibly dogs, are suspected of having such skills. But it’s rare. You need to have evolved in a highly complex social group if this ability – to put yourself into the minds of others – is going to give you a concrete advantage. We can see how that is the case for chimpanzees and dolphins, and we can see how advantageous the skill could be for dogs too (although if dogs really do have that ability, it evolved remarkably quickly). But without such social pressures – in hyraxes, for instance – there’s no advantage to attributing mental states to others. And without mental-state attribution, so much of communicative context becomes opaque and useless: irony, exaggeration, subtle implication, and, crucially, reading between the lines. Dogs don’t need to understand your words to understand some context, such as tone of voice. But the deeper mysteries of ironic contradictory statements will probably forever be beyond them.

Human language is an outstandingly complex idea. It’s huge. There’s word meaning, and word order, and context too, and all this bound up with a brain that can think about the past and future, and objects that don’t exist, and all the possibilities that are both possible and impossible … No wonder the study of human language is a science in itself. But it’s not the topic of this book. In this chapter, I’ve given some insight into the nature and structure of human language, only as a foil against what we see in the animal world. Yes, there is a lot in common: animals have some syntax and even some sounds that behave a little like words, and they sometimes communicate complex ideas, although more often simple ones. But animals don’t combine all these abilities with explosive effect as we do. We’ll probably never know exactly how we evolved to be so far removed in faculty from our nearest relatives, but it’s as good a guess as any to say that there was in all probability a cascade of innovation, one development feeding another in an accelerating rush towards infinite faculty. Word meaning on top of word order, context on top of word meaning, then more syntax on top of that, and so on. Never forget that, together with such communicative innovations, there were in parallel vital developments in our cognitive abilities – understanding relationships between individuals, objects, time and space. A web of evolving innovations feeding off each other, rather than a single path of gradually increasing complexity. Until here we are now: we’ve moved so far away from what animals do, and moved away so quickly, that direct comparisons between ourselves and other species seem almost childish. It should be clear that ‘Do animals have language?’ was never a good question. All the same, we’ve uncovered pretty much all the foundational elements of language in other species. We can see enough similarity between the way we talk and the way animals talk that we still want to know what we have in common, not just how much we are different. We may not think that animals have a language, but we still want to talk to them. Could we ever really do that? Do they have enough of what is needed – even if falling short of a true language – to hold a conversation with a human?

62.

Conclusion. If we could talk to the animals …

After a while, with the parrot’s help, the Doctor got to learn the language of the animals so well that he could talk to them himself and understand everything they said. Then he gave up being a people’s doctor altogether.

The Story of Doctor Dolittle by Hugh Lofting

We all want to believe animals can talk to us. I want to believe that. And animals can talk. Just not the same way we do. There is a crow sitting on the ledge outside my window right now. Turning its head to the left and right so that it can see me better. With eyes on either side of their heads, birds have a disjointed view of the world that we surely struggle to imagine. One eye sees to the left and one eye sees to the right, with no overlap. Yet their brains integrate that into a single perception. You cannot really put yourself into the mind of a bird if you stubbornly hold on to the way we humans view the world, with both eyes pointing forward, seeing a single scene, with an acute sense of depth perception that birds lack.

So it is with communication. As long as we insist on imagining animals communicating with the same equipment as we have, the same ears and eyes and brains, we cannot be in their world, and cannot understand what they are saying. But it doesn’t take too much effort to step outside ourselves and our modern human world, and see, hear, and think about things more as animals do. There are intelligent, communicating creatures all over the world, and in this book we have looked at just six. Six species that I have chosen because their complex communication shines a little light on the similarities and differences between what animals say and what we say. Six species that are champion communicators of the animal world, and yet we struggle to understand what they are saying. We don’t understand, first, because we don’t live in their world. We don’t see and hear as they do, but more importantly, we’re not looking or listening for the things that they are. We don’t share their preoccupation with finding food, or avoiding predators, or attracting mates. You can’t understand animal talk if you don’t look out for the things they’re looking out for. Second, we don’t understand them because we expect them to be like us. We want them to be like us. When we talk to our pet dogs and cats, we really, really want them to understand us. And to some extent they do, but they are a special case – the product of thousands of years of domestication, where both we and they have worked hard on creating a common communication.

We can understand animals if we see them for what they are, see them in the world and in the lives in which they truly live. By doing that, we see the real animals, what they are really saying, not what we want them to say. That is a much more satisfying way of appreciating the true diversity of life on Earth. And, undoubtedly, there are still some things that we share with the rest of the animal world – signals and messages that are genuinely common to all species. Even if it’s not really language it’s something that bonds us to the rest of animal life on this planet, and so is something well worth understanding.

Why talk to the animals?

We’ve certainly spotted several shared elements of language over and above the semantics and syntax and context of human language discussed in the previous chapter as well as things like the emotion of messages in wolf howls, the infinite variation in dolphin whistles, the musical abilities of gibbons. There’s no doubt that we share so much. But at the same time, we can’t just shoehorn our understanding of things like music and emotion – not to mention words and sentences – into the worlds of other species. Just because we use clever tricks of language to communicate doesn’t mean that other animals use the same tricks, even if they make use of the same tools. And the reason for this is that we communicate for different reasons. Once you have a language, as we do, oh yes, it makes perfect sense to write stories and compose poems. But for others, such arcane pursuits simply don’t come into consideration. How animals talk is dictated by why they talk, and I hope that I’ve given a few clues to some of the ‘why’: to keep in touch; to signal who’s around and who’s needed; to let others know how you’re feeling, what your needs are, with whom you want to be and whom you want to avoid. We humans certainly are different from animals, not just in the way we speak, but more importantly, in the way we think about the way we speak. Our ancestors found themselves needing particular skills – for social interaction and social communication – that the species around them didn’t need. And we ourselves still do.

Perhaps we feel we simply must be able to talk to the animals, because not being able to do so is a display of our limitations and flaws. As a scientist, I’m probably more susceptible than most to such arguments – if there’s information out there, let’s go get it! But there’s also the feeling that perhaps animals have some secrets that they can divulge to us. Not secrets in some science-fictional way, no stories of ancient dolphin civilizations or insights into laws of nature we hadn’t imagined. Rather, secrets about who they are and how they live. Sociology, anthropology, psychology are all so much easier to study in humans because of the simple expedient of being able to ask people questions. Imagine if we could present surveys to gibbons or parrots and write a whole sociology of animals. Of course, that cannot be a realistic goal, given that these animals never evolved to conceive of a language, and so can never truly understand all the questions we would like to put to them. But there is understanding to be gained from tapping into the communication of other species, and we would certainly like to access that understanding.

There are also ethical reasons for sharpening our communication with animals. In the past, ‘talking to animals’ has mostly meant giving orders to animals – closely tied with our training of them to perform tasks for us. Not all such tasks are necessarily cruel or exploitative, of course. Sheepdog training, for example, is a good case where a true communicative relationship is built on the basis of mutual understanding. But no one has asked sheepdogs if they want to herd sheep – although most people who’ve ever worked with Border collies will tell you that they’re very happy to do so: if they aren’t herding sheep or doing something else equally challenging, then they’re tearing around the house in frustration, destroying everything in sight. Still, if animals do have the capability to communicate with us with at least some sense of agency and intention, then we are surely obliged to facilitate that. I claim that dolphins enjoy participating in our scientific experiments – but I’d feel a lot better about that if they could actually confirm it. On the other hand, we mistreat (and eat) so many different kinds of creatures, perhaps we are better off not hearing what our dogs and cows and chickens would have to say.

In this journey through six species we have expanded our understanding of what animals are thinking about when they communicate, but as scientists, we like to set ourselves clear goals in our research, and then assess whether we are approaching solutions to the problems we have set. I posed several challenging questions in the introduction, so it’s worth revisiting them to see whether we are any closer to answering them.

What do animals mean when they speak? Do they have things to say beyond what we know – or what we could possibly know?

I hope I’ve given a sense of just how unfamiliar the world of animals in the wild is to us. Our usual methods of inferring what others are saying and thinking just doesn’t work across species. We are good at interpreting the intentions and the hidden thoughts of other humans, because we have evolved to be good at predicting the future actions of our social partners. None of this has prepared us particularly well to interpret animals and their signals, sounds, and intentions. So we cannot simply use intuition to interpret what animals mean. Instead, we need to drill down and look at how the animals themselves live their lives. Once we do that, we see that the amount of information they need to convey to each other is, in most cases, limited – at least relative to our own speech and language. We should not be surprised that animals don’t say very much, because we don’t see good indications of them actually using large quantities of communicated information as we do. It is true that wolves could ask for help from their pack mates, and chimpanzees could express even more subtle personal desires and intentions. But the parakeets in Chapter 3 still tugged in opposite directions on the same twig when trying to build a nest, and the hyraxes in Chapter 4 showed no sign of saying anything more than ‘Look at me!’ What animals mean when they speak is closely correlated with what they need to do. Animals that do many different and complicated things (like chimpanzees and dolphins) probably communicate different and complicated information – but only about those things that they need to do. Animals that do little (like hyraxes) probably have little to say.

Nonetheless, I think I’ve also shown that animal communication is still a very young science – it has been only a hundred years or so since Karl von Frisch showed the huge potential for communicating information in the humble honeybee. We must be modest and recognize that, even today, our understanding of what animals are saying to each other is based on the limited amount of information we can gather while crudely hacking our way through jungle, or swimming far too slowly to keep up with a pod of gliding dolphins. We try to make connections between the sounds that an animal makes and the behaviours they display – this is a very simplistic way to build an understanding of a communication system. Perhaps the next generation of animal behaviour scientists will find a better way to probe the minds of the gibbons in the jungle and the wolves in the tundra.

What do we really understand about what our pets say to us – and can we extend that to wild animals?

When so many animals surround us in our homes, there are also assorted people with a deep understanding of animal communication. There are plenty of horse whisperers, and dog trainers et cetera.fn1 In most cases, however, these people work with domesticated animals that are familiar and easy to train – and what’s more, the tasks we ask of them are relatively practical: ‘Gallop as fast as you can, but don’t throw your rider off.’ ‘Don’t poop on the carpet.’ We should question whether our ability to understand our pets really advances us at all in our quest to communicate with wild animals on their level.

To some extent, the answer is yes. We know that, even without language, all animals communicate, and do so using signals that are surprisingly straightforward, if not universal. If you’re an animal, showing your teeth and lunging at someone is always going to send an aggressive message. If that sounds obvious and trivial, you’re already well on your way to understanding most animal communication. The ‘big secret’ of animal whisperers is just as trivial: observe your subjects as if they are animals, not as if they are human. When you approach an unfamiliar dog in the street, the subtle signs of their body language are the bread and butter of most animal communication. Are their legs tense, ready to run away? Are they trying to look bigger than you (aggressive) – or smaller than you (submissive)? Put yourself in the world of a dog, living in the wild and surrounded by other creatures, both tasty and dangerous. How would you respond? In the Introduction I mentioned the ritual British greeting ‘Turned out nice today.’ How peculiar that sounds now (if it didn’t sound peculiar then). We humans expect of animals similar kinds of ritualized signals to those we use ourselves. But ritualized signals are so often arbitrary that it’s rarely possible to translate them from one species to another. Showing your teeth is a very obvious aggressive signal – in dogs, chimps, even dolphins – simply because teeth can bite. But in humans, grinning has been ritualized to be a signal of pleasure. Who’d have thought? This signal has undergone an arbitrary change of meaning – so don’t expect your smile to be understood by other species.

Some people find it easier to communicate with animals than others. Obviously, experience helps – those who have grown up around dogs and cats will understand their communication more than those who have never been socially involved with any animals and have no benchmarks except their own human communication. But some people seem to have a special advantage. Temple Grandin, Professor of Animal Science at Colorado State University, has written extensively about the relationship between the world view of people with autism and animal communication.1 Grandin, who is autistic herself and didn’t speak until the age of three and a half, argues that people with autism have an understanding of communication that is more similar to the way animals communicate, and therefore can bring important insights into how to understand – and be understood by – animals. She has applied this insight in very practical ways, completely revamping welfare standards for farm animals by designing stockyards from the animal’s point of view, for instance with curving tracks to take advantage of the animals’ natural herding behaviour. The subject of autism and its implications for communication in humans (and between humans and animals) is a huge topic, and one to which I couldn’t possibly do justice here. But Grandin’s basic idea is that people with autism tend to rely less on strict relationships between concrete concepts and their linguistic representations, and we’ve found a similar more flexible sense of meaning in all of the animals we’ve looked at in these chapters. Our idea that there is a one-to-one relationship between a word and a ‘meaning’ is not just difficult for animals to understand, it can be difficult for neurodivergent humans to understand too. Temple Grandin is a bubbly, slight figure, bursting with enthusiasm for anything to do with animals. When I first met her many years ago as a new postdoctoral researcher, she asked me what my research was about, and I replied with my standard elevator pitch about the songs of hyraxes. Quite bluntly, she replied, ‘I don’t know what that is.’ But when I then described these small furry animals, jumping from boulder to boulder and calling out a long sequence of notes to advertise their territory, she immediately understood, and became absolutely captivated with the idea. Professor Grandin’s premise is that people with autism rely more on visual mental images to conceptualize ideas – she needed that image of a small furry animal standing on a boulder before she could really grasp what I was saying. And, according to her theory, animals perceive concepts in a similar way: words mean little or nothing to animals, but both animals and autistic humans rely on a more non-linguistic representation of concepts.

Temple Grandin’s ideas are interesting, but not yet mainstream. It’s pretty difficult to test them in any rigorous way. But it’s a good starting hypothesis. My experience of students with autism is that they bring interesting and enthusiastic perspectives to the study of animal communication. Maybe that’s because diverse ways of looking at the world bring diverse ideas. Indeed, one of the reasons that neurodivergent young people often make exceptional scientists is precisely that they see links and connections that more conventional perspectives miss, and this is exactly the change in perspective that we all need if we are going to understand what animals are saying.

Our pets are very different from wild animals; millennia of domestication have changed them almost beyond recognition from their wild ancestors. But not completely. At least with dogs and cats we can sit down, observe, and interact with them, and they are happy for us to observe and interact. Real communication with our pets is not about teaching them human words (‘sit’, ‘lie down’, ‘drop it’); real communication is about observing the animal in them. If you forget about any intention to train your dog to ‘sit’, what do you see when you spend time with him? Very much what you would see were you to spend time with a pack of wolves. Behaviours like expressing annoyance (perhaps just getting up and moving to another spot in the room) or expressing a desire for social interaction (licking your hand or lying next to you). These concepts are the true vocabulary of animals – not words and sentences – and the more you spend time with your animals, the more of this true vocabulary you will notice.

Is it reasonable to assign to animals the kinds of concepts, conversations, and language that we ourselves have?

Or, perhaps it is unreasonable to compare animals and humans directly. Somewhere there is a dividing line between what we can reasonably say about animals based on our own behaviour, and what is so uniquely human that making that cross-species comparison is foolish and unhelpful. So many of the concepts that I’ve talked about in the preceding chapters as being expressed by animals in their communication will sound familiar to us as humans. Emotions such as fear and desire, boasting and reconciliation. Once upon a time, scientists and philosophers claimed that animals did not have emotions as we do – now we know the opposite to be the case. Emotions have been evolutionary drivers ever since the first animals existed. Eat. Don’t be eaten. Reproduce. Look after your family. At that level, we should not be surprised that we share so much with other species. Where our own lineage has diverged so sharply from other animals in the last million years is in those complex functions of our brains that seem to have a purpose beyond simply survival and reproduction. Abstract thoughts and ideas, imagination, and language itself, would seem to be based in the neocortex, a part of the brain that is a much larger proportion of this organ in humans than in any other species. Does that mean that animals can’t have imagination? No. We’re still far from understanding what imagination is and how it’s generated in the brain. But it’s no coincidence that our in-depth journey through the communication of six different species has found that almost all the communicative messages we can see appear to relate to emotional states, rather than intellectual ones. That’s not a definitive finding, but it certainly implies that when we look at what animals mean when they communicate, we should be considering more how they feel, rather than what they think.

I’ve said – or at least implied – that no species of animal apart from humans has a language, but I’ve not defined what a language is. Is it necessary to give a clear definition? In the scientific world, clear definitions of language are controversial things, and they often hinge either on obscure subtleties of computational linguistics, such as exactly what kind of grammar is used, or on unknowable properties of our mental state, like exactly what does the speaker understand when they say something. But a definition of some kind is a useful thing. Very many people I encounter tell me, ‘Animals must have a language: they communicate with each other, don’t they?’ We could, of course, simply equate language with communication and the problem goes away, but by doing so we would be doing ourselves, and science, a great disservice. What we humans do, what we do practically, what we build and write and invent, is so clearly something different from what all other animals do that there seems to be a different mechanism at work. And science is about understanding mechanisms. Language is different from ‘just communication’, but where to draw the line isn’t very clear. Perhaps for now it doesn’t have to be. It is true that there will always be cases that are difficult to interpret – Alex the parrot, for instance. Did he have a true capacity for language or not? But even unusual and difficult to interpret cases don’t detract from the main distinction: we are not limited in what we can say, whereas every species without language is tied to a small handful of concepts they can communicate. Coming then, as humans and animals would appear to do, from those two radically opposed perspectives, perhaps it is as difficult for us to understand animals as it is for animals to understand us. But some scientists feel differently.

As I write this, in early 2023, there are a number of new initiatives based on the latest artificial intelligence to ‘decode’ animal communication – mostly focused on cetaceans like dolphins and whales.2 I touched on this idea in Chapter 2. Their rationale is that advances in machine learning have reached the point where – given enough data – a computer can pull out the meaning in animal signals and translate them into human language. Whether or not this is a realistic goal, at the very least it’s probably a worthy one. There is no doubt that new tools and artificial intelligence algorithms like neural networks can organize and classify animal signals, and break them down into components that have some natural relationship. For example, in the chapter on dolphins we saw that there is no clear answer to the question of whether two similar dolphin whistles are variants of the same signal, or whether they are two quite distinct signals. Machine learning can probably help with such questions – although there’s little substitute for asking the animals themselves. Among the cetaceans, it’s not just dolphins that use complex communication: whale song, particularly humpback whale song, is complex and multi-layered, with different elements being combined into motifs, which are then combined with a certain amount of variation into longer songs. It is a very appropriate goal to apply artificial intelligence to making sense of such complex songs, determining where one part ends and another begins, and picking out patterns like motifs shared between individuals, or even characteristics of the response that one animal gives to the call of another. But that is not the same thing as saying that dolphin whistles or whale song can be translated.

Surely this depends on whether there is something language-like that is waiting to be translated in the first place. We don’t currently know how much information the cetaceans intentionally transmit. Most scientists think not so much, or at least, not information that is language-like, in the sense of words and sentences, distinct concepts, questions and answers, and so on. If that is the case, then aiming to achieve a translation of a whale song is not a very meaningful goal. But we can be modest in our understanding of the behaviour of animals, particularly elusive animals like whales and dolphins. We don’t really know all that much about their behaviour and what they need to say to one another. There may be more going on there than we think, and we’ve just missed all the interesting language-like behaviour. Nonetheless, we’ve looked and looked and not found any indication that humpback whales, or any other species, actually use language in the way that we do. That is, we don’t see these animals performing behaviours where we would think, ‘Hmm, language might be an advantage if you’re going to do that.’ We’ve never seen any sign that these species need to use a language. Nothing about the behaviour of wolves or dolphins or even humpbacks gives any indication that having a language like ours would be useful to them. And so, such a language is unlikely to evolve.

That is not to say that we can’t achieve useful information from putting whale song through a neural network. Most probably songs contain lots information about the individual that is doing the singing – maybe even information about what that animal wants (e.g. a mate). And, of course, I could be wrong in my scepticism. An excellent reason to proceed with such AI projects is that they give an opportunity to test my hypothesis that dolphins don’t speak like we do. Nothing in science is more exciting than finding evidence that a generally accepted hypothesis is incorrect. I would love to discover that humpbacks really do talk in words. And if the opposite is true: if our computer algorithms show us that whales actually don’t speak in words? Would it be a disappointment to discover that, in fact, only humans really do have a language? Definitely not – we should be revelling in the animals as they are, not as we want them to be.

How different are we really from animals, and how much of that is due to our language?

In the chapter on chimps, we came tantalizingly close to finding a tangible connection between humans and other animals – a similarity between ourselves and chimpanzees that we could almost reach out and touch. Those creatures that are uncannily similar reflections of our own nature seem to possess almost every human characteristic that we can list – and we can be tempted to conclude that the only thing that really makes them not human is their lack of language. Could it be as simple as that? Almost 300 years ago, Julien Offray de La Mettrie proposed to a shocked French society his belief that an ape, properly trained to know a language, ‘would be a perfect man, a little gentleman’.3 For his rationalist views he was ridiculed and had to flee France for Prussia. Now, with the benefit of an understanding of evolution and natural selection, and with a century of important, if scant, archaeological evidence, we can piece together some of the six-million-year journey in which our ancestors slowly became more and more different from their cousins, the ancestors of the chimpanzees. Still, we can’t point to a single event, or even a single species, and say, ‘This is where non-humans became humans.’ Our tools, our culture, our care for family – none of these seem to be clear dividing lines. It’s not easy to imagine what happened as a non-human primate became a fully fledged human. It is possible that there really was one moment (perhaps as in the Stanley Kubrick movie 2001: A Space Odyssey) when a light was switched on in our minds – perhaps, one morning when a baby ape was born with the ability to speak a language. But then, that baby wouldn’t have had anyone to talk to.

I suggest that, rather than language appearing suddenly to divide our ancestors from the rest of creation, language was the inevitable outcome of a process that was already taking place in the brains of intelligent primates, long before they were known as humans. In fact, the evidence that modern chimpanzees show many of the features that would seem to be essential for the evolution of language implies that our common ancestor – that jungle-living ape of central Africa six million years ago – probably also possessed these key abilities, and passed them on to all its descendants, both human and chimp. Key among these was the ability to know your own thoughts, and to know that other individuals have thoughts too. Of all animals on our planet, very few have this ability. There is some evidence – although not always very good evidence – that a handful of species (chimps and elephants being two of them) can look in a mirror and understand that the image they see is actually themselves, and not another animal. Once you understand that you are truly an individual, it is quite likely that you must then understand that others are individuals too. And if other chimps, or elephants, are separate individuals from you, they must also have thoughts of their own, and desires and intentions of their own. The complex alliance-building behaviour of modern chimpanzees is a good sign that they understand at least something of manipulating other individuals, trying to understand what others are thinking and turning that to their advantage. And once that complexity of consciousness has been achieved – perhaps only once that has been achieved – then an animal’s brain has the complexity necessary to support some kind of language. You can convey complex ideas only because your brain is capable of thinking such complex ideas. Of course, that complexity of consciousness isn’t a guarantee of language – chimps are apparently lacking that big leap – but it may be that such brains are necessary for language, and that is why no other animals have what we have.

In the beginning, life communicated. The very first organisms of which we know lived in bacterial mats in shallow lagoons 3,800 million years ago. In all likelihood these bacteria communicated with each other, just as bacteria communicate today. Trapped in close proximity by their inability to move, they secrete chemicals to signal messages to their neighbours, what nutrients are plentiful or absent, whether their mat is overcrowded or not – far more communication than you might expect from the simplest of single-celled organisms. Another two billion years after that, cells came together to form more complex organisms: the ancestors of the plants, animals, and fungi that we see today. How can cells come to work together in unison? Only through communication. Today too, the cells in your body communicate through a complex and still incompletely understood network of chemical and electrical signals. When to lift your arm, when to increase your heart rate, when to attack invading or mutated cells. The complexity of life – any complexity of life at all – relies on communication. About a billion years ago, the ancestors of all animals evolved, and they had a very special ability: they were multi-cellular organisms that could move. Now these organisms faced a new challenge. Unlike the bacteria in mats, these almost-animals constantly moving around might end up being distantly separated from each other. Communication took on a new dimension: finding your friends. Sex had already evolved a billion years earlier – how were these creatures to find a mate? How to ensure that their offspring – potentially dispersed throughout the environment – would survive and flourish? Success of offspring is the currency of evolution. There was huge pressure on these potentially very lonely, nomadic creatures to stay in touch with each other. On the early Earth, communication was mostly done with chemicals – if you can sniff your way towards the food, then you have a means to interpret chemical messages sent by other individuals. But as the need for complex communication grew, the chemical medium wasn’t flexible enough – smells and tastes are easily mixed and confused in the water currents of the marine environment. Luckily, organisms were already evolving other sensory systems. Movement produces vibrations, and if you’re looking for moving prey, or if you’re looking out for moving predators, then sensing vibrations in the water is an important skill. And sound is really just vibrations. So sound sensing evolved, and with that, the ability to produce sound too.

When animals and plants began to colonize the dry land, the diversity of environments available to them exploded in number and complexity. Animals specialized into very particular niches, and to be best adapted to such specific tasks, became more and more complex both in their structure and in their behaviour. Already the world was dominated (as it still is to a large extent) by the arthropods: insects and their relatives with a hard external skeleton such as spiders and crustaceans. Insects in particular were phenomenally successful and adapted to a wide range of niches that included complex societies such as termite nests and ant colonies. In such huge agglomerations of thousands of individuals communication was vital. Maintaining the colony and similar tasks required signalling where help was needed, foraging for food required signalling where new food sources could be found, and protecting against predators and invaders required warning signals. The pheromone trails of ants and the waggle dance of bees are undoubtedly complex communication, but the information they could contain remained limited. Why? One reason is that hard external skeleton. Insects and their relatives could never really grow very large and could never really evolve the complexity – particularly the brain complexity – of larger organisms because there was nothing rigid to support their soft insides. The innovation of an internal skeleton was crucial in allowing the evolution of vertebrates – animals with more complex information processing abilities. Brains, defined in the most general way possible as the information processing part of an animal, are where complex communication comes from and where it goes to.

As animals evolved with the flexibility in size to house bigger brains, then their ability to communicate grew. Frogs croaked to advertise that this particular pond belonged to them. Dinosaurs roared warnings and flashed coloured scales at each other. Two groups of animals had particularly interesting communication needs. Birds could fly over long distances looking for food and nests. They needed a communication system that could convey messages about their territory from tree to tree and could pass reliable signals to their mates and their offspring. Complex acoustic messages were an ideal solution to communication in the treetops, where sound travels well, and vision is often obscured. These tiny flying dinosaurs had the flexibility to exploit every environment from the jungle to the Antarctic, and the parrots evolved to exploit a niche that required intelligence and complex communication. Perhaps even almost language. But, like insects before them, flying animals are constrained by the rigorous requirements of their lifestyle: they need to be lightweight, and they need a lot of energy to enable them to fly. Few species could afford to divert weight and energy to a large brain, and so the parrots remain unusual among the 10,000 species of birds alive today.

Then there were the mammals. Small, mostly nocturnal burrowing creatures, whose best defence against marauding dinosaurs was to stay out of their way during the day and be active at night when sun-loving cold-blooded predators didn’t have the energy to chase after them. Being nocturnal meant that mammals evolved large eyes to see in the dark, and sensitive ears to hear the rustling of prey. And with big eyes and sensitive ears came big brains to process all that complicated sensory information. What a perfect storm of abilities – all the foundations necessary for complex communication, lined up in a single group of animals. Then, when the climate change brought on by a massive asteroid strike spelled the end of the giant cold-blooded reptiles, mammals burst forth from their burrows and specialized into thousands of different and new niches. The fundamental complexity of the mammal brains together with the burgeoning complexity of the newly forming ecosystem led to a dizzying range of new forms of communication: communication for attracting mates, for marking territory, for signalling danger to family, and for building and maintaining complex societies. Long before the dinosaurs died, the ancestors of the hyrax may have been singing to their rivals just as modern hyraxes do today. But from those simple beginnings sprang the diverse mammals we have met in these chapters. Wolves, in a lineage that specialized in hunting, together with the cats and bears and weasels, were mobile and fleet of foot, and needed to communicate to keep in touch with their families over long distances. Some mammals crawled, hippopotamus-like, into the seas and evolved to take advantage of the vast environment available there, becoming the dolphins we see today. Like wolves, their communication need was driven largely by the huge underwater distances, but the challenges of life in the sea also drove their cooperation and their intelligence – and that was reflected in the complexity of their communication.

On land, in the forests and jungles, things took a different course. Monkeys and their relatives leveraged those mammalian traits of intelligence to the full: in the complexity of the jungle, they could cooperate to find food, defend territories, and even manipulate their environment to their own benefit. Some, the ancestors of the gibbons, turned the capacities of their large brains towards singing. Others used their brains to allow more cooperation, larger groups, and more complex interactions. Just six million years ago, one offshoot of our chimp-like ancestors set off on a rollercoaster ride of rapid evolution, as their ability to talk and their brains that controlled not just talking, but also complex cooperation, grew and grew. Bursting out of the jungle, their descendants now cover the world, and have changed it almost beyond recognition.

Here we are. After 3,800 million years, animals still communicate. But our world is far more complex than the salty lagoons filled with bacterial slime from which we originated, and our communication is correspondingly more complex. Right in the very last 0.02% of that history of life, language evolved. If the history of life – the history of communication – were compressed down to a whole day, language evolved in the last twenty seconds before midnight. Is language really so special, or is it just the latest fad – another specialist adaptation like the spectacular colours of a butterfly or the absurdly long tongue of an anteater? When we compare ourselves to animals, and compare our communication to that of animals, it would be good to remember that we are only a small part of the greater ecosystem of Earth, and that our language, impressive though it is, is just one adaptation to communication out of millions. Rather than thinking of what we humans can do as being so special, we need to view our abilities as an extension of those of our ancestors, and of our cousins who live around us today. The more we move away from human exceptionalism, the more we can understand animals in their own context, and the more open our minds will be to the kinds of radically different communication all around us. There is really nothing to lose, except our perception of sitting on a throne at the pinnacle of creation. Which was always an illusion anyway.

Thank yous …

First and foremost, I have to thank the inimitable Professor Angela Dassow, my across-the-board collaborator and closest human friend, who has supported me both in my research and in many difficult times, including the loss of my best friend of fifteen years, Darwin. He, in turn, inspired me and comforted me and did everything a dog should do. Except live for ever. Together with Angela are the other members of our Bioacoustics Research Group, puppy musician Dr Holly Root-Gutteridge, wolf/bear/jackal turned squirrel expert Dr Beth Smith, trainer and zookeeper Loretta Schindler, and red wolf conservationist and fiction author Amy Clare Fontaine. Despite being spread across the world, we all still meet weekly to plan our ongoing assault on our ignorance of the meaning of animal communication. Then there is Dr Sara Torres Ortiz, the multi-talented dolphin trainer, dolphin researcher, parrot researcher, and drone pilot, whose apartment in Tenerife became our base for both research and leisure.

I’ve made use of the published material of many other colleagues, and the Further Reading section mentions many of them, but special thanks go to Dr Cat Hobaiter, who gave me a better insight into the lives of chimpanzees than anyone could have, without me actually going out to see them in the wild. Professor Irene Pepperberg too gave me an incredibly useful back-and-forth on African grey parrots. I wish I had met Alex while he was alive.

In the field, there have been too many people to thank sufficiently. Tho Duc Nguyen comes first and foremost – there is no other person who could have arranged logistics, permits, porters, equipment, and still have the ability to race up a jungle-covered mountain ascent that I myself barely survived. I’d trust Tho with anything.

Back in quiet Cambridge, Girton College has supported me well, and, of course, my students have challenged me well. Connor Brown, my editor at Penguin Random House, has done a great job with suggesting where to expand, where to contract, and if you feel I’ve been too wordy or not wordy enough, it’s probably because I overrode his judgement.

My father Lester and son Simon read each chapter as I finished it and gave the first genuine feedback. They almost invariably disagreed with each other, but I think that just points to the wide readership I hope that this book will have.

Most of all, though, I owe a debt to both the named and the nameless animals who have been the essence of what I have written. The wolves of Yellowstone National Park and of northern Italy, whom I’ve seen, and the wolves of Wisconsin and of northern Spain, whom I’ve only heard. Torak and Mosi of the UK Wolf Conservation Trust, who are now both gone as well. Achilles and Ulysses the zoo dolphins of Tenerife, as well as the wild and habituated dolphins of Eilat in Israel. Whole aviaries full of African grey parrots, and wild monk parakeets too numerous to count. Not to mention so many hyraxes … And, of course, those vulnerable cao vit gibbons, beautiful, haunting, and teetering on the edge of extinction. I shudder to think of a world where no one will ever hear that reverberating ‘caaaao vit’ penetrating through the jungle.

And to you the reader. If you put down this book, and go out in the world, and see the animals therein, and hear them. And understand. Understand that they have their world that is at once alien and familiar, complex and surprisingly straightforward. If you can do that, then I’ve done my job.

Arik Kershenbaum

Girton College

April 2023

Notes, and some suggestions for further reading

Introduction

Perhaps you’ve come to this book having already read much about animal communication. There have been a few books published by scientists about particular species, like Baboon Metaphysics by Dorothy Cheney and Robert Seyfarth, or more general ones like Are We Smart Enough to Know How Smart Animals Are? by Frans de Waal. Both of these I recommend. But sometimes the best introduction to the life of animals is through intelligent fiction. I mentioned in the Introduction Watership Down by Richard Adams, and Wild Animals I Have Known, by Ernest Thompson Seton – both excellent examples of sufficient anthropomorphism to allow the reader to relate to the characters, but containing enough knowledge and wisdom of natural history to teach us about the true lives of these animals.

Although I do not cite this book specifically, I also recommend (if you can find a copy) The Private Life of the Rabbit, by Ron Lockley, which, apart from being the inspiration for Richard Adams’s Watership Down, also shows how scientific observations of wild animals really can impart an almost fiction-like narrative to the true lives of real animals.

I also mention:

1 The Pleasure of Finding Things Out, by Richard P. Feynman.

Feynman was a physicist, but a champion of popular explanation of the most complex scientific principles. His books are all a pleasure to read.

Chapter 1: Wolf

So many books have been written about wolves, about the lives of wolves, living with wolves, or the biology of wolves. Finding background material on wolf communication is not difficult. Yet I place my recommendations with the experts:

1 ‘Silverspot, the Story of a Crow’, in Wild Animals I Have Known, by Ernest Thompson Seton.

Seton, probably the most famous nature writer of the early twentieth century, wrote from the perspective of someone who lived so close to the wild he described that the reader is instantly transported into his world. I recommend reading as much Seton as you can find.

2 Two books by Rick McIntyre, The Rise of Wolf 8 and The Reign of Wolf 21, give great detail on the lives of Yellowstone wolves, from their most experienced observer. His books turn decades of field notes into a coherent and compelling story – rather like The Private Life of the Rabbit – every scrap of which is true.

3 Apart from general chats with fellow wolf researchers, I’m particularly grateful to my colleague Emma Narotzky, whose MA thesis ‘Humans and Howls’ is very enlightening, and a great read (downloadable from Montana State University).

4 See Chapter 8, ‘The Battle of Lamar Valley’, in Rick McIntyre’s The Reign of Wolf 21.

5 See The Nature of Fear: Survival Lessons from the Wild, by Daniel T. Blumstein. Dan’s broad perspective on the evolutionary relationship between our own behaviour and the behaviour of other animals is in many ways the core of what I have to say in my own work. His motto and advice to us all is ‘See your inner marmot’.

6 If you want to know more about how advanced technologies like MRI scanning can help us peer into the minds of animals, I recommend a book by Gregory Burns: What It’s Like to be a Dog.

Chapter 2: Dolphin

As with wolves, there is no shortage of books – fiction and non-fiction – about dolphin behaviour and dolphin communication. Justin Gregg’s Are Dolphins Really Smart? is a good place to start, as well as the books by Denise Herzing listed below.

1 The Genesis of Animal Play, by Gordon Burghardt, goes into great detail about different kinds of play across the entire animal kingdom – including insects!

2 Dolphin Diaries: My 25 Years with Spotted Dolphins in the Bahamas, by Denise Herzing, is a wonderful description of how dolphin research is really carried out in the wild.

3 For those interested in the details, you can see my 2013 paper, ‘The Encoding of Individual Identity in Dolphin Signature Whistles: How Much Information is Needed?’, which is widely available online.

4 Stephanie King at the University of Bristol is a leader in the research into dolphin communication in the wild. This particular finding is from her group’s 2022 paper, ‘Strategic Intergroup Alliances Increase Access to a Contested Resource in Male Bottlenose Dolphins’, published in the PNAS.

5 The setting for the fantastic BBC/Animal Planet TV series Meerkat Manor. Like The Private Life of the Rabbit, and The Reign of Wolf 21, this TV series used fiction-like (but entirely true) narratives, creating a kind of soap opera around the lives of a population of meerkats in the Kalahari. The Kalahari Meerkat Project is still running today, thanks to Tim Clutton-Brock and Marta Manser, gathering long-term data on the behaviour of these engaging little animals.

6 This was the work of the late Louis Herman, and later Adam Pack, at the Dolphin Institute in Hawaii.

Chapter 3: Parrot

Undoubtedly, some of the most interesting background to my parrot chapter can be found in the books of Irene Pepperberg (below). But there are plenty of other resources for those interested in parrot life too: Parrots of the Wild, by Catherine Toft and Timothy Wright is my particular favourite, both charming and detailed.

1 You can read about Alex’s story in the popular book Alex and Me by Irene Pepperberg.

2 Simon Tamungang at the University of Cameroon is one of the few true experts in wild African grey behaviour.

3 For a much more detailed description of the experimental procedures and results, see The Alex Studies by Irene Pepperberg.

Chapter 4: Hyrax

There have been few (if any) books written on the hyrax, but I encourage you to go to the internet and find some of the many videos people have shared of hyrax singing. The sound is so remarkable and so surprising that there are endless examples available. In the scientific literature, papers by Amiyaal Ilany, Lee Koren, and Vlad Demartsev as well as myself provide most of what we know about this unusual creature.

1 The distinction between grammar and syntax is subtle and differs from discipline to discipline. I’m going to take the liberty of using syntax to mean any non-random ordering of words or sounds, and grammar to mean a set of rules that provides actual meaning to that order of words.

2 For those of you interested in the maths, the number of different ways of ordering a song that’s k notes long, made up of n different notes, is (n + k − 1)!/k!(n − 1)!, which for five notes, and a twenty-nine-note song, is equal to 40,920.

Chapter 5: Gibbon

Perhaps surprisingly, there are few popular books that have been written about the lives of gibbons. The scarcity of literature regarding these animals, difficult but fascinating to study in the wild, is one that should be remedied. It is amusing to read Charles Darwin’s accounts of gibbon behaviour in The Descent of Man, but the only really comprehensive contemporary description of the lives of gibbons can be found in The Gibbons of Khao Yai by Thad Bartlett (2009).

1 Taken from Jeremy and Patricia Raemaekers and Elliott Haimoff, ‘Loud Calls of the Gibbon (Hylobates lar): Repertoire, Organisation and Context’, Behaviour 91(1/3) (1984): 146–89.

2 Taken, as is most of the data here on lar gibbons, and especially the transition diagrams, from Dr Angela Dassow’s doctoral thesis ‘Exploring the Interior Structure of White-handed Gibbon and Rat Vocal Communication’, downloadable from the University of Wisconsin-Madison.

3 Ibid.

4 Ibid.

Chapter 6: Chimpanzee

In contrast to gibbons, chimpanzees are well represented in the popular literature. First and foremost among these are two books by Jane Goodall: In the Shadow of Man, and Through a Window, both of which are engrossing and captivating narratives of the early years attempting to understand our closest relatives. Other books deal with the behaviour of chimps in captivity, such as the many books by Frans de Waal, and Andrew Halloran’s The Song of the Ape. For a more comprehensive look at the species, try Chimpanzee, by Kevin Hunt.

1 Explaining the evolution of social structure has historically focused on the advantages for males, not for females. Whether or not this is a bias of male scientists, or whether it is a valid evolutionary approach, is a complex and unresolved question.

2 Taken from Sven Grawunder et al., ‘Chimpanzee Vowel-Like Sounds and Voice Quality Suggest Formant Space Expansion Through the Hominoid Lineage’, Philosophical Transactions of the Royal Society B, 1 March 2022.

3 Adapted from Catherine Crockford and Christophe Boesch, ‘Context-Specific Calls in Wild Chimpanzees: Analysis of Barks’, Animal Behaviour 66(1) (2003): 115–25.

4 Published online at https://greatapedictionary.ac.uk/

Chapter 7: Human (you)

Here, to understand humans and human language, I leave the reader to their own devices. There is no shortage of material, although I will always nudge the serious towards Shakespeare, whose works contain enough about human nature to satisfy almost any curiosity.

1 It’s worth mentioning that although Jane Goodall was the first scientist to observe chimpanzees using tools, the hunter-gatherers of central Africa, like the Twa people, have long known of this behaviour in our nearest relatives. In any case, Goodall’s book Through a Window: 30 Years Observing the Gombe Chimpanzees, is a wonderful introduction to these animals.

2 From Claire Spottiswoode, Keith Begg, and Colleen Begg, ‘Reciprocal Signaling in Honeyguide–Human Mutualism’, Science 353(6297) (2016): 387–9.

3 Ádám Miklósi’s book Dog Behaviour, Evolution, and Cognition is the standard reference if you want to know more about this.

4 From Sarah Marshall-Pescini, Camille Basin, and Friederike Range, ‘A Task-Experienced Partner Does not Help Dogs Be as Successful as Wolves in a Cooperative String-Pulling Task’, Scientific Reports 8 (2018), https://doi.org/10.1038/s41598-018-33771-7

5 In fact, even in English there are many words that describe varieties of snow: slush, powder, blizzard, sleet, etc. Yupik and other Eskimo and Inuit languages often use long and complex words that are made up of multiple components. Just one word can be a whole sentence, e.g. in Yupik (according to anthropologist Igor Krupnik) ‘matsaaruti’ means ‘wet snow that can be used to ice a sleigh’s runners’.

6 I am very grateful to my colleague Dr Karen Lewis, professor of philosophy and linguistics at Columbia University, who not only gave these examples, but constantly reminds everyone in our research group: context is the most important thing!

7 Taken from Tecumseh Fitch’s book, The Evolution of Language.

Conclusion

The Doctor Dolittle children’s stories, written in the 1920s, are hardly a good place to start reading to find out more about talking with animals. The books I’ve recommended in the previous chapters are helpful, but – dare I say it – books can only take you so far. No book will tell you more about the great outdoors than the great outdoors itself. To understand animals, you have to see animals: in the home, in the garden, in the zoo, or in the wild.

1 I strongly recommend the 2010 HBO biopic made about her life: Temple Grandin. In addition, Grandin has written a number of books, including Animals in Translation: Using the Mysteries of Autism to Decode Animal Behavior.

2 Two examples active in February 2023 are The Earth Species Project https://www.earthspecies.org/ and Project CETI https://www.projectceti.org/

3 Man a Machine, by Julien Offray de La Mettrie.

Index

The page references in this index correspond to the print edition from which this ebook was created, and clicking on them will take you to the location in the ebook where the equivalent print page would begin. To find a specific word or phrase from the index, please use the search feature of your ebook reader.

Page references in italics indicate images.

ABBA, 162

abstraction (feature of language), 241

Adams, Douglas: The Hitchhiker’s Guide to the Galaxy, 57, 75, 85, 203–4

Adams, Richard: Watership Down 3, 253

advantage, evolutionary, 6, 7, 29, 31, 32, 85, 106, 140, 147, 151, 153, 159, 166, 175, 194, 219

advertising

cognitive ability, 101

group membership, 67

male fitness, 122, 124, 134, 155, 157, 159

territory, 39, 41, 50, 122, 148, 152, 180, 239, 248

Aesop, 3, 88

aesthetics, appreciation of natural world and, 12

African grey parrots, 87, 90–107, 98, 100, 101, 102, 106, 112, 113–15, 174, 197, 205, 209, 213–14, 220, 223, 242, 251, 252, 256. See also parrots

aggression, 102, 220, 237, 238

Ake the dolphin, 82, 223

alarm calls, 7, 129, 160–62, 164, 166, 170, 179, 218

albatrosses, 149

Alex the parrot, 87, 90–92, 93, 95, 96–105, 106, 106, 112, 113–15, 174, 197, 205, 209, 213–14, 220, 223, 242, 251, 252. See also parrots

alien intelligence, 56

alliances, 67, 177, 245–6

amplitude modulation, 35

ants, 248

apes, 13, 16, 141, 144, 145–6, 147, 149, 151, 152, 170, 173, 175, 192, 199, 244–5. See also individual ape species

aphorisms, 10

arbitrariness (feature of language), 216

arthropods, 247

artificial intelligence, 76, 77, 242–3

artificial language, chimpanzees and, 190

association, cognitive, 92, 93, 94, 96, 105, 106

audience effect, 137–8

Australopithecus, 188

autism, 238–9

automata, 4, 5

babbling, 150

babies, 93

bacteria, 246–7, 250

barks

chimpanzee, 179, 182, 182, 185–6, 185, 187

coyote, 37

dog, 46

hyrax, 118, 121

wolf, 30–31, 33, 37

Beau Geste effect, 37

bees, 2, 6, 7, 207, 248

Beethoven, Ludwig van, 34, 36

Bible, the, 2, 120

big data, 76, 77

birds, 88, 98–9, 117–19, 148, 158, 207, 231, 248. See also individual species name

birdsong, 7, 13, 65, 102

dialects, 134

learning, 138–9, 159

See also individual species name

blackbirds, 133, 158

blowhole, 56, 58, 61

blue tits, 22, 129, 222

body language, 30, 32, 42, 189, 210, 226, 237

bonobos, 145, 151, 152, 190, 192, 198, 223

brains, 113–14, 123, 132, 160, 166–7, 209, 221, 241, 246

energy and, 128–9, 166–7, 248

burst pulses, 59, 59, 60

calls

alarm, 7, 129, 129, 160–62, 164, 166, 170, 179, 218

cohesion, 45, 45

contact, 70, 70, 71, 100–101, 160

discrete, 63, 215–17

distress, 66, 99–100

graded, 63, 72–3, 182, 183, 215–16

cao vit gibbons, 143, 144, 144, 145, 147–8, 170, 252

Čapek, Karel, 4

captivity

chimpanzees and, 174, 179, 183, 193, 194

dolphins and, 79–83

parrots and, 89, 90–91, 97, 109

wolves and, 41

cats, 17, 63

chaffinches, 133–4

Chaser the border collie, 213–14

chemical sensing, 59

Cheney, Dorothy: Baboon Metaphysics, 253

chickadees, 129, 158

chiffchaffs, 155

childhood, extended, 106

chimpanzees, 3, 13, 14, 16, 21, 22, 99, 173–200, 203, 205, 210, 223, 224, 236, 244–6, 250

ape evolutionary family tree and, 150, 151–2

bark, 179, 182, 182, 185–6, 185, 187

calls in the wild, 181–4, 182

culture, 173–4

dictionary, 196–9

gestures/visual communication, 17, 99, 145, 178–80, 180, 181–2, 189, 198–9, 203, 216, 219

humans, similarities with, 173–4

hunting, 184–8, 185

lying, 194–6, 228

pant-hoot, 180, 180

societies, complex, 175–7, 189–90, 194, 200, 219, 228

teaching to speak human, 188–93, 191

Chomsky, Noam, 221, 222

Clarke, Arthur C.: Dolphin Island, 75–6

clicks, dolphin, 59, 59, 60, 61–2, 63

cognition, 76, 82, 108, 114, 145, 158, 187, 197, 215, 223

social, 177

cohesion calls, 45, 45

colobus monkeys, 185, 186

Colorado State University, 238

communication

bacterial, 246, 250

cellular, 246–7

chemical, 59, 246, 247

complex, 14, 25, 89, 90, 104, 119, 136, 145, 147, 149, 160, 167, 170, 175, 186, 187, 215, 219, 232, 242, 247, 248, 249

inter-species, 225

visual, 17, 99, 145, 178–80, 180, 181–2, 189, 216, 219

companionship, social need for, 108

complexity, 17, 128

balanced, 169

definition, 166–9

as message, 149

randomness and, 138

societal, 10, 68, 99, 175, 189

songs and, 123–4

syntax and, 136

concepts

abstract, 95, 106

number of, 21, 114, 198, 205–6, 206, 208–9, 210, 213, 221, 242

conditioning, operant, 93

conflict, 29, 40

consciousness, 4, 246

contact calls, 70, 70, 71, 100–101, 160

context, 217, 224–8, 225

cooperation

chimpanzees and, 175, 185, 187, 194, 197, 199, 200, 204

communication and, 28, 29

dogs and, 209–14, 212

dolphins and, 60, 67, 78, 79, 81, 82, 84, 85

gibbons and, 148, 149, 159

honeyguides and, 207–9, 208

hyrax and, 120

inter-species, 207–14, 208, 212

parrots and, 111

rearing young and, 149

coordination, chimpanzee, 185, 187–8

copying

dialects and, 48

dolphin whistles, 63

howls, 48

parrots and, 89

song, 102–4, 102, 134–5, 150

syntax, 134–6

understanding and, 93–7

Covid-19, 174

coyotes, 2, 37, 49, 78

‘Creation of Adam’ (painting), 221

crows, 88, 228, 231

crustaceans, 247

culture, chimpanzee, 173–4

curiosity, 55, 81

dancing, 41

Darwin the dog, v, 205, 210n, 225–6, 225

Darwin, Charles, 6, 16, 144, 149–50, 154, 162; The Descent of Man, 144, 149, 257

Dassow, Angela, 36, 36, 50, 83

de Waal, Frans, 257; Are We Smart Enough to Know How Smart Animals Are?, 253; Chimpanzee Politics, 195

deception, 194–6

deer, 3, 22, 31, 40, 43, 46, 120, 122, 123

Dennett, Daniel, 7

Descartes, René, 4, 7

deterrence, 51

dialects, 48, 134

dice, 132

dictionary, chimpanzee, 197–8

dinosaurs, 92, 117, 248–9

discrete sounds, 63, 73, 74, 215–17

discreteness (feature of language), 215–16

displacement, 99

as feature of language, 215

display, 120, 123, 129, 174, 189

distress calls, 66, 99–100

diversity

call types, 48, 61

environments, 247

information, 154

notes, 157, 160, 167

sounds, 18

species, 21, 146, 232

Doctor Dolittle, 11, 231, 234

dogs, v, 1, 3, 7–8, 9, 219

grammar and, 223, 226, 227, 228

human-animal communication and, 209–14, 212, 224–8, 225

languageness and, 205, 206

wolf communication and, 31–2, 42, 44, 46, 47, 47, 51, 52, 53

dolphins, 9, 15, 38, 55–86, 114, 170, 176, 202, 206, 210

in captivity, 79–83

clicks, 59, 59, 60, 61–2, 63

fission-fusion society, 66–8, 114

language, existence of, 84–6

non-signature whistle, 68–73, 70

questions, asking, 79–84, 82

signature whistle, 64–74, 65, 77, 84, 101, 218, 255

sounds made by, 58–60, 59

spinner, 56

training, 76, 79–83, 84

translating language of into human language, 75–9

whistle, 21, 38, 56, 56, 59, 60, 61–77, 62, 64, 65, 83, 84, 101, 124–5, 182, 205, 215–16, 217, 218, 233, 242, 243, 255

words and, 72–5

domestication, 207, 232, 237, 239–40

of dogs, 210–13, 240

dominance, 99, 101, 121

fighting and, 122–3

hierarchy, 108–9, 176–7

indicators of, 131

duality, patterning, 216–17

duets

bird, 13

gibbon, 148–9, 149

Dungeons and Dragons, 131n, 150

ears, evolution of, 249

echolocation, 59, 60, 61

Eilat, Israel, 65, 252

electric communication, 17, 215

electric fishes, 215

elephants, 7, 13, 117, 212, 228, 245

emotions, 49, 164, 193, 240–41

energy, evolution and, 11, 128, 153, 166, 248

Eötvös Loránd University, Budapest, 210

escapes, zoo, 186–7

Eskimo languages, 220, 259

ethics, 234

ethology, 6

evolution, 6

advantage and, 6, 7, 29, 31, 32, 85, 106, 140, 147, 151, 153, 159, 166, 175, 194, 219

energy and, 11, 128, 166–7, 248

language, 139

experiments

chimpanzees and, 174, 183, 188–9, 192, 193, 194–5, 198–9, 221

dogs and, 211–12, 223

dolphins and, 66, 81–3, 82, 162, 235

gibbons and, 161

parrots and, 91–8, 115, 220

See also individual experiment name

eyes

bird perception and, 231–2

dolphin, 59

eye contact, 22, 211

nocturnal mammal, 249

parrot, 87, 98, 108–9

primate, 147

families

family groups, living in, 110, 148, 149–50, 175–6

gibbon, 148, 149–50, 178

wolf packs as, 27–8, 29, 52, 114

farming, 46–7, 48, 49–51

fear, wolves and, 50

Feynman, Richard, 12, 253

fighting, dominance and, 122–3

fission-fusion society, 66–8, 114

flies, associating stimulus with a response and, 96

food, 2, 3

calls for, 195–6, 197

chimpanzees and, 182, 183–4, 186, 189, 194–6, 197, 203, 219, 222

foraging, 85, 90, 109, 121, 147

gibbons and, 147, 148, 158

hyraxes and, 120, 121, 122

parrots and, 89, 109, 115

single-male group evolution and, 176

foraging, 85, 90, 109, 121, 147

fossils, human, 189

frequency modulation, 35, 62

Frisch, Karl von, 6, 6n, 7, 236

frogs, 248

fruit, ripe, 109, 147

fur, 11, 14, 24

Gardner, Alan & Beatrice, 189

generalization, 84, 190, 196, 211

genetics, 48, 49

gestures, chimpanzee, 99, 178–9, 182, 189, 198–9, 203, 216, 219

gibbons, 143–71, 175, 176, 180, 182, 202

alarm calls, 159–66, 163

cao vit, 143–6, 144, 147–8, 170, 252

evolution of, 145–7, 152

family groups, 147, 148, 157, 158, 175, 178

language of, 169–71

long arms, 16, 147

song of, 16, 147–71, 148, 153, 156, 163, 165, 233

Vietnam and, 74, 143–4, 144, 146, 146, 148, 203

white-handed, lar, 145, 147–8, 152, 153, 155, 156, 157, 161, 165, 169, 170, 257

Gombe, Tanzania, 181

Good, the Bad, and the Ugly, The (movie), 195

Goodall, Jane, 179, 181, 182, 189, 196, 202

gorillas, 145, 147, 152, 176, 178

graded calls, 63, 72–3, 182, 183, 215–16

Graham, Kirsty, 198

grammar, 127–8, 160, 196, 222–4, 241

syntax and, 128, 139–41, 256

Grandin, Temple, 238–9

grinning, 238

grooming, 179, 195

groups, 107–8

size, 29, 66, 85, 107–8, 114, 122, 175–6

structure, 157–9

growls, 30–31

Gua the chimpanzee, 188–9

gunboat diplomacy, 29

habituation, 181

Halloran, Andrew: The Song of the Ape, 186, 197–8, 257

herds, 176

Herzing, Denise, 76

hieroglyphics, 216

Hobaiter, Cat, 198

Hockett, Charles, 214–16

Homo habilis, 202, 206

honest indicator, 123

honeyguides, 207–9, 208

horses, 213, 237

howls, wolf, 11, 21, 23–5, 26, 30, 31–53, 33, 44, 45, 47, 60, 61, 62, 82, 124–5, 148, 174, 180, 219, 233

captivity and, 41, 174

dialects and, 46–9, 47

dolphin whistles and, 61, 62

function of, 32–8, 34, 36

howling survey, 36

human communication with wolf and, 49–51

meanings of, 38–46, 44, 45

spectrogram comparisons of, 34, 36, 45, 47

humans, 201–30

context and language of, 224–8, 225

cooperation and language of, 201–4

definition of language and, 201–6, 206, 214–30, 225

dogs and, 209–14, 212

human-animal communication, 207–14, 208, 212

order and language of, 220–24

words and, 218–20

humpback whales, 76, 242, 243, 244

hunter-gatherers, 226

hunting

chimpanzee, 184–8, 185, 197, 199, 200

dolphins, 67, 78

individual roles, 185

wolves, 25, 27, 28, 37, 41, 46, 249

hyraxes, 17, 117–41, 118, 177

dominance among, 121–4, 131, 135–6

evolution of, 117–22, 249

meaning and song of, 137–41

mental-state attribution and, 228

social groups, 120–21, 124, 126, 138

song, 16, 21, 118–19, 121–5, 124, 125, 132, 135, 152–3, 154–9, 156, 162, 169, 215, 219, 222, 223, 228, 236, 239, 249, 252, 256

syntax and song of, 118–19, 128, 130–41, 154–9, 156, 222, 257

imagination, 31, 241

improvization, 135

individual recognition, 33, 66, 68, 77, 180

infinite faculty, 201, 203

information

chimpanzee communication and, 175, 178, 179, 180, 181–3, 186, 187, 198–9

dolphin communication and, 62, 67, 85

gibbon song and, 159, 160, 162, 163, 166–9, 170

hyrax song and, 127, 128, 130–32, 153, 220

parrot communication and, 96, 100, 101, 109, 115

processing, 87, 248

quantity of, 166

wolf communication and, 33–4, 35, 38, 42

insects, 247

intentionality, 137, 182, 243

Inuit languages, 220, 259

irony, 226, 228

Israel, 65, 135–6, 252

jackals, 37, 47, 51, 120

James, Etta, 162, 163

jazz, 134, 136

Judas Priest, 162

jungle, 143–6, 146, 148, 173, 174, 236

Kalahari Meerkat Project, 70, 255

Kant, Immanuel, 3

Kanzi the bonobo, 190, 192

Kellogg, Winthrop & Luella, 188

Kershenbaum, Arik: Zoologist’s Guide to the Galaxy, The, 9, 217

Koko the gorilla, 192, 193, 199

Kubrick, Stanley, 245

Lana the chimpanzee, 190, 191, 192, 223

language

definition of, 6, 22, 139–41, 179, 192, 196, 202, 204–7, 206, 214–17, 229–30

evolution of, 68, 90, 91, 107, 124, 140, 154, 157, 159, 171, 193, 202, 204, 217, 221, 245, 250

features of, 201–2

‘fingerprints’ of, 222

human, see human

Inuit and Eskimo, 220, 259

statistical properties of, 166–70

teaching to chimpanzees, 188–93, 191

teaching to parrots, 104–7, 106

See also individual species name

languageness, 92, 205, 206, 214

lar gibbons, 147–8, 148, 152, 153, 155, 156, 157, 161, 165, 169, 170

laughter, 179

Lazzaroni, Martina, 46

learning

chimpanzees, 174–5, 188, 189, 190, 192, 193, 197, 199, 221

dolphin, 76, 79, 81

gibbon, 150

honeyguide, 209

hyrax, 119, 125, 127, 128, 133–4, 136

open-ended, 134

parrot, 89–90, 92, 93–4, 97–8, 102, 104–7, 106, 112–13, 114, 170, 174

song, 119, 125, 133–4, 136

syntax, 119, 133–4, 136

wolf, 48, 49, 50

lexicon, 72–3, 198–9, 207

linguists, 118–19, 127, 128, 190, 192–3, 215, 221

lions, 2, 39, 57, 122

Lockley, Ron: The Private Life of the Rabbit, 253, 254, 255

Lorenz, Konrad, 6n

Loro Parque Zoo, Tenerife, 97

lyrebird, 102

macaws, 97

mammals, 38, 59, 73, 88, 90, 117–18, 119, 120, 185, 197, 248–9

mating, 3, 13, 27, 30, 32, 78, 121–2, 124, 129, 138, 147, 149, 150, 169, 176–7, 179

McIntyre, Rick

The Reign of Wolf 21, 39, 254, 255

The Rise of Wolf 8, 254

meaning

abstract, 93

chimpanzee sounds and, 179–80, 182, 186, 188, 196, 198

complexity and, 25, 128, 138–9, 155, 202

context and, 224–8, 225

defined, 137–9

dolphin whistle and, 60, 63, 64, 68–9, 71, 73–5, 77

gibbon song and, 154, 155, 159–60, 162–4, 166, 170–71

grammar and, 126–8, 137–9, 140, 141

honeyguide and, 209

hyrax song and, 137–9, 140–41

order and, 220–24

parrots and, 87, 92

wolf howls and, 25, 30, 31, 33–5, 38–46, 48–9, 51, 52–3

word order and, 127, 140, 218–20, 239

meerkats, 70–71, 70, 160

melodies, 63–4, 64

memory, 78, 147, 158

mental-state attribution, 193, 208, 228, 241

merge operation, 222

Michelangelo, 221

mimicry, 15, 87, 91, 100, 102, 103, 113, 114

mirror test, 245

mobbing behaviour, 129

mockingbirds, 134, 155, 158

mole rats, 17

mongooses, banded, 126–7

monk parakeets, 109–13, 110, 112

monkeys, 2, 7, 12, 13, 145, 146, 160, 185, 218, 220, 222, 249–50

Morgan, Tan, 71

moths, 17

movies

Disney, 3

horror, 25, 47

See also individual movie name

Mozambique, 208

Mozart, Wolfgang Amadeus, 34, 64, 154

M/R model-rival technique, 103, 105, 106, 106, 107, 112, 113, 209

MRI, 44

music, 17, 19, 20

composition, 130, 134–5, 144

dolphin whistles and, 63–4

gibbons and, 149, 154, 162, 163, 233

hyraxes and, 130, 133–6

spectrograms and, 19, 20

wolf howls and, 34

mythology, Icelandic, 2–3

names, 65–8

Nazism, 6n

neocortex, 241

nests, 109–11

neural networks, 76, 242, 243

Nguyen, Tho Duc, 251–2

Nim Chimpsky (chimpanzee), 192, 198, 221, 222

noisy sound, 30–31, 33

nouns, 83, 190

nuance, 69

octopuses, 74

Offray de La Mettrie, Julien, 259

onomatopoeias, 216

orangutans, 145, 151, 152

orca, 78

oxytocin, 211

pair-bond, 108, 114, 149

pant-hoot, 180, 180

parakeets, 89, 97, 99, 109–13, 110, 112, 236, 252

parrots, 15–16, 21, 83, 87–115, 149, 170, 174, 175, 197, 199, 205, 209, 213, 220, 256

African grey language-like skills, 87, 90–107, 98, 100, 101, 102, 106, 112, 113–15, 174, 197, 205, 209, 213–14, 220, 223, 242, 251, 252

diet, 89–90, 147

group living/social skills, 89, 107–13, 110, 111

intelligence, 88–9, 98

learning, interactive, 104–7, 106

M/R model-rival technique and, 103, 105, 106, 106, 107, 112, 113, 209

monk parakeets, 109–13, 110, 112

reference and, 93–7

sounds, 97–104, 98, 100, 101, 102

Parsons code, 63–4, 64

pattern generators, 132

Patterson, Penny, 192

peacocks, 138

Pepperberg, Irene, 90, 92, 96, 114, 209, 251, 256

personhood, 194

perspective taking, 113, 194–6, 228, 239

pets, 18, 91, 109, 237–40

pheromones, 17, 248

Phoenicians, 118

pictographs, 216

Pinker, Steven, 7

Planet of the Apes (movie), 199

planning, 186, 188

plants, 89, 96

play, 51, 57, 58, 76, 78–9

plumage, 17, 123

prairie dogs, 160

predators

chimpanzees and, 179–80

dogs and, 210, 211

dolphins and, 71, 78, 85

gibbons and, 158, 160, 161, 162, 163, 164, 165, 165, 169, 170

hyrax and, 120, 121, 124, 126, 129, 129

parrots and, 89, 108, 109

top, 25, 78

wolf as, 25, 31, 40, 43, 46, 47, 48, 50

primates, 11, 145, 147, 151, 158, 159, 160, 179, 196–7, 205, 212, 245

problem solving, 88

pronunciation, 219

pseudowords, 150

psychology, experimental, 4

putty-nosed monkeys, 222

rabbits, 118, 120, 121

randomness, 130, 131, 133, 136, 137, 138, 139, 167, 169, 192

recognition, individual, 26–7, 33

red wolves, 37–8, 49

reference, 93–7, 113, 209

religion, 3, 6–7

repertoire, vocal, 16, 62–3, 68, 72, 114, 129–30, 139, 152, 160, 167, 168, 197

repetition, 130, 132–3

representations, mental, 84

resources, scarce, 109, 157

ritualization, 10, 78, 140, 203, 219–20, 238

rivalry, 29

robins, 3, 11, 133

robots, 3, 4, 5, 141, 161

Root-Gutteridge, Holly, 47

rough grunt, 183–4

Rowling, J. K., 13

Rumbaugh, Sue & Duane, 190

rumination, 120

Russell’s circumplex model, 43–4, 44

Russignan, Martina, 46

same-different experiment, 83–4

Sarasota Bay, Florida, 66

scavengers, 28, 211

seet call, 129, 133, 166, 205

semantics, 215, 218, 220, 226, 227, 233

sentences, 42, 52, 126–8, 190, 192, 199, 223, 224, 226, 227, 228, 233, 240, 243

sentinels, 121

Seton, Ernest Thompson: Wild Animals I Have Known, 26, 253, 254

sex, evolution of, 247

Sex Pistols, 162, 163

Seyfarth, Robert: Baboon Metaphysics, 253

Shakespeare, William, 13, 258; Hamlet, 201

sharing information, 96

Shave and a Haircut (riff), 36

sheepdogs, 46, 47, 213, 234

shrimp, 62

siamangs, 157

sight, see vision

sign language, 105, 174, 189–90, 192, 193, 197

signature whistle, 65–74, 65, 77, 84, 101, 218, 255

singing, 2, 140

evolution of, 41, 144, 150, 151–2, 151, 250

gibbon, 144, 148, 149, 150, 151–2, 151, 159, 162, 169, 250

hyrax, 122–4, 125, 131, 132, 134, 137, 249, 256

learning, 102

whales, 18

Sistine Chapel, 221

skeletons, 247, 248

smell, 17, 30, 59, 247

Smith, Beth, 50

society, 16, 41

complex, 10, 14, 21, 30, 68, 79, 108, 175, 200, 219, 247, 249

fission-fusion, 66–8, 114–15

interactions in, 104–6

song, 42–3, 65

copying, 102, 134–5, 136, 150

female, 150

gibbon, 147–8, 149, 150, 152–5, 159–60, 162–9, 163, 170

human, 162

hyrax, 118–19, 121, 122, 123, 124, 125–6, 125, 127–8, 129, 130–31, 133, 136, 137–9, 140, 154–8, 156, 159, 162, 215, 219, 222, 239

whale, 242–3

songbirds, 102, 114, 119, 125, 128, 129, 133–4

song sparrows, 134

sound

language and, 223, 229

most important medium of communication on Earth, 18

production, 181–2

sensing, 247

spectrograms and, 19–20

travelling around objects, 181–2

underwater, 58–9

sounds

discrete, 63, 73, 74, 215–17

graded, 63, 72–3, 182, 183, 215–16

Spain, naming of, 118

spectrograms

‘Born to be Wild’, 19, 20, 21

context and, 225, 225

defined, 19

dolphins, 56, 56, 59, 59, 61, 62

hyrax, 124, 124

parrots, 100, 100, 101, 101

understanding, 19, 20, 21

wolf howl, 34, 34, 36, 36, 45, 45, 47, 47

speech, human, 8, 33

spiders, 247

squawks, 99–101, 100, 101

starlings, 2, 130, 222

storytelling, howl of wolf and, 42

swans, 149

syntax

complexity and, 131, 132, 133, 136, 137, 138, 139, 140, 141, 155, 156, 157, 221–4

copying of, 134–6

defined, 131–2

evolution of, 132–3

gibbon song and, 155–7, 156, 162

grammar and, 139, 141, 222–3, 224, 256

human ability with, 221–4, 229

hyrax song and, 118–19, 130–33, 132, 134–6, 135, 137, 138, 140–41, 154–7, 156, 222

learning, 119, 130–33, 132, 134–6, 135, 137, 222–3

meaning and, 137–8, 139, 140, 223–4, 229

origin of, 139–41

ubiquitous in animal world, 119, 130–33, 139–41, 152, 223

Tanzania, 179, 181, 202

Tay (language), 203

telepathy, 7, 9–10, 56

termite fishing, 173, 184–5, 202

Terrence, Herbert, 221

territoriality, 40

advertising, 39, 41, 115, 122, 148, 155, 157, 180, 230, 239

food and, 148, 167

tigers, 13, 13n, 18, 39, 161, 164, 165, 166

Tinbergen, Nico, 6, 6n

tits (bird family), 129–30, 222

Todt, Dietmar, 105

Tolstoy, Leo: War and Peace, 126, 127, 130

tonal sound, 31, 33, 101

tools, use of, 88, 173–4, 202

Torres Ortiz, Sara, 83, 97, 251

toxins, 89

trade-offs, 34, 168

training animals, 76, 81, 82, 83, 84, 104, 105, 106, 113, 224, 234

transition diagrams, 164, 165, 165

translation, 8, 72, 74, 75–9, 238, 242, 243

2001: A Space Odyssey (movie), 245

UK Wolf Conservation Trust, 41, 41, 42

understanding, language ability and, 93–7

verbs, linguistic ability and use of, 83

vertebrates, evolution of, 248

vervet monkeys, 160, 218

Vietnam, 74, 143–4, 144, 146, 146, 148, 203

vision

chimpanzees, 17, 30, 178, 179, 181–2, 189

communication and, 17, 178, 179, 181–2, 189

dolphin, 59

underwater, 59

vocal control, evolution of human language and, 150

volume, variation in, 71

waggle dance, 17, 248

warm-bloodedness, 117

Washoe the chimpanzee, 189, 190, 192, 193, 196, 198, 223

whales, 7, 18, 76, 130, 242–4

whistles

dolphin, 21, 38, 56, 56, 59, 60, 61–77, 62, 64, 65, 83, 84, 101, 124–5, 182, 205, 215–16, 217, 218, 233, 242, 243, 255

parrot, 21, 99, 100–102, 100, 101, 102, 103

wolf, 124–5

white-handed gibbons, 145, 147, 257

Williams, Robin, 192

Wolf Science Centre, Vienna, 210

wolves, 23–53

bark, 30–31, 33, 37

caution, 25–6

communication in the pack, 29–32, 114

dialects, 46–9, 47

dogs and, 210–11

dolphin communication and, 57, 60, 62, 67, 74, 78–9, 81–2

howl of see howl, wolf

human communication with, 49–53

human fear of, 24, 49–50

hunting, 25–6, 27, 28, 37, 41, 46, 249

play, 27, 51, 78

red, 37–8, 49

social groups/wolf pack, 15, 21, 24–5, 27–32, 33, 36, 37, 39, 40, 41, 42, 48, 49, 50, 51, 52, 53, 57, 108

Yellowstone studies into, 26–7, 27, 40, 45–6, 62, 78, 254

words

chimpanzees and, 190, 192, 196, 198, 199

communication without, 9

dogs and, 213–14, 224–8

dolphins and, 72–5, 76

emotional states and, 43, 44

gibbons and, 171

lack of in animals, 171

meaning and, 38–9, 42, 52, 69, 126–7, 140, 198, 217, 218–20, 239

order of, 83–4, 119, 127, 128, 140, 196, 205, 217, 223, 229

parrots and, 89, 90, 91, 92, 97, 100, 209

syntax and, 119, 224

tone and, 33

understanding, 209

Zipf’s Law, 168–9

Yao people, 208. 208

Yellowstone National Park, 26–7, 27, 40, 45–6, 62, 78, 252, 254

zebras, 57, 149, 175–7

Zipf’s Law, 168–9

zoos, 12, 16, 32, 48, 80, 81, 97, 100, 173, 174, 178, 183n, 186–7

THIS IS JUST THE BEGINNING

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First published by Viking in 2024

Copyright © Arik Kershenbaum, 2024

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ISBN: 978-0-241-99530-3

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Footnotes

Introduction. Everybody’s talking … but no one says a word

fn1 Tinbergen and von Frisch, both staunch anti-Nazis, shared the Nobel Prize with Nazi collaborator Konrad Lorenz, whose compassionate observations on animal behaviour in the wild don’t sit well with his role in guiding genocidal Nazi policy.

fn2 Although the most famous sabre-toothed ‘tiger’, Smilodon, isn’t closely related to today’s lions or tigers at all.

fn3 This number is according to a study by Google Books in 2010.

4. Hyrax

fn1 There are 5⁷ (78,125) ways of organizing five notes in a seven-note song.

fn2 As Dungeons and Dragons players will know, there is no five-sided die. However, you can roll a ten-sided die, with each number appearing twice.

5. Gibbon

fn1 Readers of a younger generation may like to refer to the classic but slightly creepy 1971 song of that name by Middle of the Road.

6. Chimpanzee

fn1 Bread may not sound as interesting as an apple to you, and, in fact, chimps in different zoos do have different preferences, with some also preferring apples to bread.

7. Human (you)

fn1 Darwin was, as I wrote this, sixteen years old and rarely bounced up at all, but still showed enthusiasm in his own way when it was time for a walk.

fn2 Red Apple was the title of a book by Phillip Deery, subtitled Communism and McCarthyism in Cold War New York. Context again: understanding of the title of this book only becomes possible when you realize that New York is the ‘Big Apple’.

Conclusion. If we could talk to the animals …

fn1 Not to mention those who say they can understand what animals say and vice versa, whose claims we might take less seriously.