Animals can talk
N. J. BERRILL
ONE OF man’s greatest distinctions, so men say, is our power of speech. Certainly we love to hear the sound of our own voice and rarely do we really listen to anyone else’s. Perhaps if we talked less and listened more we might realize that many other species speak besides ourselves, although in their own ways and in their own time. When a dog barks, a bird sings, a frog croaks or a monkey chatters, it conveys information to another of its kind as definitely as though you had asked a friend to dinner or told a tramp to keep away. Most of the noises made by non-humans are for purposes of communication.
It’s not just a storyteller’s fancy
that dogs, cats, squirrels, whales and monkeys can converse. Here a famous zoologist
discusses what they say and how they say it
Yet speech is more than the mere making of sounds issuing from your mouth and the next time you are engaged in conversation with a close acquaintance, sit back and take a dispassionate view of the procedure. Watch your friend’s face, his hands and everything about him that can move. You will see him frown, smile, shrug his shoulders, wave his hands about—all of which tells you something of his thoughts, desires, intentions and feelings. A barely visible wink can carry a world of meaning, and if only we could wiggle our ears like a dog or a donkey, to express approval, fear, or interest, what a host of messages we might semaphore without making any sound whatever. All of it is part of language and man can communicate with man without saying a word, as anyone knows who has seen a Charlie Chaplin film or the French mime Marcel Marceau. Signs and sounds both play their part and in neither respect do we stand alone.
In spite of our own tendency to chatter, however, everyone is either acutely or vaguely aware that cats and dogs make themselves understood within certain limits. At times in fact a cat seems to be exclusively some sort of vocal instrument, although one that is badly out of tune. A cat’s serenade on the rooftop at night is clearly and unmistakably a call to arms, with apparently more agony of yearning put into the song than any love-sick human has ever managed. When scared and unable to flee it arches its back, twitches its tail, snarls and spits in such an alarming way that most sensible dogs recognize the meaning of the message and leave well alone. A cat has one meow when it is hungry and another when it simply has to go outside, and it has an insidious combination of leg rubbing and purring which is suspiciously like coaxing. A mother cat uses one tone to her kittens and another to her boyfriends.
Dogs howl when unhappy or frustrated, yip with excitement when there is a walk in prospect, growl when alarmed or angry, and bark in answer to another’s call. All of it may stem from emotion, as a spilling over of feeling under this circumstance or that, but it is still language insofar as other dogs know the meaning of the sounds. Probably many of a dog’s facial expressions and tail attitudes are essentially involuntary accompaniments of the dog’s feelings and reactions, but they are constant accompaniments which can be read by other dogs, just as a look of horror on a human face is both involuntary and yet conveys meaning.
How much any dog understands of human speech has been a topic of argument for a long time. What is certain is that a dog receives vital information, from its own point of view of course, from the tone of his master’s voice and that the words themselves are not of great importance. Also a dog watches intently for barely perceptible signs which he has come to associate with impending activity. There is evidence that a dog may comprehend the meaning of an isolated name word in much the same way that we do, although the very difficulty we meet in proving this shows how little of true verbal speech dogs really understand.
Most animals have their distinctive call and, since most creatures are gregarious in some degree, the sound made by a fellow being usually denotes not only companionship of a kind but safety as well. Yet noisemaking is a hazardous undertaking for most wild animals and a silent secret form of communication is much safer most of the time. This is one that depends upon scent but, because our own sense of smell is so degenerate, we are inclined to overlook it and in any case find it difficult to investigate. But smell looms large in the world of four-footed mammals. They have a large variety of scent glands, placed in some cases between the bases of the hoofs or at the ankle level, in others by the tail or between the hind legs, and again in many others between the nose and the eyes. In every case they are used to mark scented trails either on the ground or on branches of trees. Martens and mongooses smear branches or bark with a glandular secretion; dogs mark almost every other tree they pass; while other animals, such as the ocelot, mark out their hunting ground with piles of manure. The purpose in most cases is probably multiple, marking territories and home range for the benefit of friend and foe. The scented signposts convey messages beyond our appreciation, but they are messages or information just the same.
Wherever animal communities exist, communication of one kind or another becomes a vital necessity, for life is too complex to be without a code of signals. Monkeys are typical in this respect, although you get a distorted view of them if you study them only in a zoo.
For the greater part of a year Dr. C. R. Carpenter, famous for his studies of monkeys and apes, observed the habits of wild howling monkeys on the small island of Barro Colorado, a wildlife sanctuary situated in one of the lakes forming the Panama Canal system. Their howling, a roar louder than that of a lion, says Carpenter, is usually heard in the early morning and late evening, echoing through the forest with uncanny effect. Travelers returning from the American tropics have described the sound as powerful, melancholy and insufferable.
The howlers use their voices primarily just as we do —for communication or signaling at a distance. They need to signal for basically the same reasons— to keep social contact between members of a clan, to keep other groups at a distance and so maintain the peace. Making a loud noise has always been a good weapon to frighten away enemies, real or suspected, and it has become the custom of howler monkey clans to raise their collective voices to say in effect, “This territory belongs to our particular clan. Keep your distance!” The noise is made by the males, for the females cannot speak by any means so loudly. They lack the overdeveloped mechanism of the male.
The howling is a matter of social adjustment. Two clans feeding in the same area would soon denude the trees of fruit and other foods, and feeding territories are mutually respected as a rule. If one clan should ignore the location signals of another and stray across the frontier, the invaded clan sets up such a howl the invaders usually withdraw. If they do not, then a battle ensues.
deep hoarse cluck means “follow me” in monkey talk. A chirp is “let’s play”
Similarly, signals are necessary in the co-ordination a monkey clan needs in order to live successfully as a group, particularly since the clan is forever on the move, foraging from place to place. When it is time to move on, the leading male gives a deep hoarse cluck—repeating the sound if necessary—and this is a signal or command to follow him. It is as distinctive and meaningful a sound as any a sergeant-major ever made. Moreover, the cluck signal is repeated as long as the clan is on the move. When it ceases the group stops and the individuals go about their individual business of feeding, tending to young, or making love.
Carpenter reports many other types of sounds and particular responses. If an intruder appi-oaches a clan, one of the males will turn toward him and make a series of deep gurgling sounds or rapid grunts, which sound somewhat like water being shaken in a jug. The other males move toward the source of disturbance, ready to raise bedlam or fight. If a youngster falls it gives a series of cries usually consisting of three notes, as though it were saying repeatedly, “Come help me;” the mother immediately lets out a wail ending with a groan, and the adult males move toward the scene of the accident to find and recover the fallen offspring. When an infant makes contact with its mother it makes a purring sound for a few seconds, which the mother responds to by coddling. Further, when young howlers are together, a little chirping sound is generally taken to be an invitation to play and is responded to accordingly. A nearby male may make a grunting noise, which, according to circumstances, stops a play fight or calls for quiet, or is often enough an encouragement to go on playing. The young monkeys suggest action and the adult co-ordinates it, in each case by means of a particular sound. Finally, when a male encounters something strange, either an object or a situation, he grunts rapidly on a note which sounds remarkably like who! who! Whatever it actually means, all the other animals of the clan become immediately quiet and listen attentively for any further sounds.
Monkey talk may be limited but it certainly is of vital importance to the welfare of the community and to the individuals composing it. Altogether the howlers have a vocabulary of at least fifteen to twenty different vocalizations, all of which appear to play an important part in controlling behavior.
Some such scheme of communication seems to have developed wherever social life has become important. Even the California ground squirrel, which is much more gregarious than either chipmunks or the tree-living squirrels, has a remarkable set of verbal symbols. To the casual listener the sound made is only one simple chirp and is only uttered when danger is suspected, but the chirp can be made to vary in pitch, loudness and inflection, depending on the message to be conveyed.
When a ground squirrel becomes aware of a bird of prey flying in its neighborhood, it utters a single short syllable of unusual loudness and carrying capacity, at which all the other squirrels within hearing dive for their burrows, while passing along the alarm signal in their turn. If the danger is a dog, coyote or a man. the signal is a distinctive triple note not used at any other time. A less urgent threat produces a different signal. If a mother with young senses danger that is not too pressing, she gives a low melodious note at intervals of two or three seconds. Altogether a system of general communication exists which seems astonishingly informative, considering the small restricted voice the animals possess.
Any creature that can be preyed upon by others and lives in association with others of its own kind is in somewhat of a quandary when it comes to making a noise. Signaling or talking by means of sound, which amounts to the same thing, may mean safety for the group but spell extreme danger for whoever gives the alarm.
This is of particular concern to birds, although bird song is employed for various purposes. For the most part, birds sing to be recognized or located— often for both reasons at the same time. One of the troubles birds have to contend with, however, is the sounds produced by other birds, all trying to signal to their own kind at the same time. For this reason most bird calls are highly distinctive, so that each kind can identify its own call amidst a medley of others. Each call carries the meaning, “I am here,” and serves to keep a foraging or migrating flock together whether the individual birds are in sight of one another or not.
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The statement, “I am here,” can carry different implications, however, according to circumstances and the nature of the listener. The song of a male robin has opposite effects on the two sexes, and so has that of many other male birds. Investigators who played i-ecords of the male chaffinch song in the countryside of England found that it attracted unmated females but repelled males, much as though it were a wolf whistle which drew all the blondes in a neighborhood but drove all the boys away. Somewhere along the line we seem to have missed a trick, although, in the case of birds, how a solitary female chooses beteeen two seductively calling males is hard to tell. Is it loudness or inflection or some undetermined subtlety in the message of the song, or what? Whatever it is, the message gets across. It is the same message that a male partridge drums on a hollow log in the woods—in this case, a typical barker’s call to all females to come and see him display his finery and resist his wooing if they can.
According to Dr. P. Marler, an ornithologist at the University of Cambridge, England, bird language is much more functional than human language. When the capacity to make and interpret sounds is limited, their use is too important to be squandered and animal language generally is serious business. Small birds, for instance, are in constant danger from large birds of prey, such as hawks and owls, and when one is sighted it is very important to communicate the information to the rest of the flock. According to Marler, chaffinches employ quite different calls, according to whether the bird of prey is perched or in flight. In the first case the chaffinch gives a “chink” note, which is short and sharp and supplies both a warning and a means of locating where the warning comes from so that all can keep an eye out for the menace. The bird making the sound can be easily located by the other chaffinches. But if the bird of prey is a hawk flying overhead and in position to swoop, the warning made by the males is a high thin “sect” note, which serves to warn but does not give away the position of the caller. All chaffinches who hear it fly at once to cover. Other birds, such as missel thrushes and blackbirds, have special “hawk” calls of their own.
Perhaps most of our understanding of bird language comes from Dr. Edward A. Armstrong, an amateur ornithologist of Cambridge—amateur, that is, inasmuch as he studies birds in his own time. His most recent book concerns the wren alone. Armstrong identified at least six different songs and fourteen separate types of call notes, each with its distinctive meaning. The songs show every gradation from loud and strident phrases, through sweet warblings, to a whisper song audible only within a few inches of the bird.
The bird voice can be modulated almost as extensively as our own, the restrictions of bird language being the result of the particular nature of the brains of the birds. A parrot can deliver a whole sentence in English, but this is sheer mimicry on the part of the bird, which merely memorizes the sequence of sounds and is able to reproduce them, but without understanding their meaning. The parrot is responsive but not speaking.
Who else speaks besides ourselves? It is an interesting question because it roughly divides living creatures into three groups. There are those who keep silent either because making a noise of any kind is dangerous or because they are incapable of producing sound. There are those who make noise because the warnings given to the flock or colony outweigh the dangers involved by the individuals who call the warning. And there are those who are so invulnerable, for one reason or another, that they can raise the roof with impunity. Monkeys do it in their treetops. We do it whenever we feel the safety of numbers or of enclosing walls. Birds do it on occasion, secure in their powers of flight. And so do certain whales.
Why do whales whistle?
Most sea creatures are silent because they have no means of making noise, but whales are mammals that have invaded the sea and have become even more fish-shaped than seals. Yet they remain warm-blooded, they bear their young alive and suckle them, they have lungs for breathing air, and they retain their vocal chords, which some whales use and some do not. The largest whales appear to be silent. They feed directly on the sea pastures, sifting out the water as they plow along, and probably all they desire is to be left alone. Why advertise your presence when the kind of attention you can get is unwanted? On the other hand, perhaps they only seem to be silent because no one has got near enough with the right instruments to hear them. But the small whales are in a different category. They are in their own way the wolf packs of the seas, highly intelligent by non-human standards, traveling in groups, fearless and carnivorous. The smallest whales are usually called porpoises or dolphins, but they are no less whales for having their own names. One of these, the white whale or porpoise, which occurs in large numbers in the lower St. Lawrence, has been studied to greater effect than any other kind.
The white whale has been nicknamed the “sea canary” and apparently not without justification. Two biologists from Harvard University recently investigated groups of these small whales near the mouth of the Saguenay River. Using an underwater microphone seventy feet below the surface and connected with an amplifier, they were able to listen to the schools of the white porpoise even though the mammals never came nearer than two hundred yards and were often as much as two miles away. Most of the time the porpoises moved in their usual series of short dives of from five to ten seconds duration, each dive carrying them forward about fifty feet.
Whenever the animals were seen coming round a bend of the river the biologists heard a variety of sounds which died away as the porpoises passed out of sight. The noises were heard as high-pitched resonant whistles and squeals, varied with ticking and clucking sounds not unlike a string orchestra tuning up, as well as mewing and occasional chirps. Some of the sounds were bell-like and some suggestad a crowd of children shouting at a distance. Occasionally there was a sharp report and at times a peculiar trilling noise, which justified the name “sea canary.” What the calls convey is not yet known, but there is no doubt that the only chatterboxes on the earth that can be compared with the porpoise are monkeys and men.
Mammals vocalize, birds sing but reptiles, without either vocal chords or singing box, can only hiss. Even then, for all its limitations, the hiss must be regarded as a warning to keep away. To most animals that can hear, the hiss of a snake is one of the most alarming sounds in the world.
Unlike the man in the pax-able who was given only one talent which he buried from fear of losing it, those cx-eatures that have but one xxxeans of communication employ it for all it is worth. This is especially the case with insects which have so little basic equipment to work with compared with birds and xxxammals but pei-form miracles with the little they have. Crickets and katydids have their pair of hearing organs in the lower joint of the forelegs; grasshoppers and cicadas have theirs in the sides of the abdomen. Both sexes can hear but only the males make noise, usually by rubbing one hard part of the body against another, using legs, wings and body in various ways according to the species. The females are tuned in to the sound made by their respective males and apparently to no other sound on earth. Yet they can be fooled by the canned edition. When a microphone is placed in a cage of males and connected to an earphone in a cage of females, the females move with active feelex-s towax-ds the sound.
Crickets chirp by day and by night, and seemingly not only when in a mating mood. They chix-p in response to any stimulation, and the chirp is often an invitation to fight to another male. They chirp fast when the air is warm and slow when it is cold, for the temperature of the cricket body rises and falls accoi'dingly and accordingly speeds or slows his actions.
In the cricket wox-ld however the sounding signals tend to run away with the game and seem to be senseless at times. One common cricket of this continent sings by the thousand in unison at night, with a short beat of about one hundx-ed per minute, so that the woods seem to pulsate with the sound. This may be purposeful or it may be simply a sort of group exercise.
Other insects talk in other ways and moths in particular communicate by means of their own peculiar perfumes wafted thx'ough the night air. The females remain seated and diffuse their scents downwind with the gentle bx-eeze. The males, each with a pair of plume-like antennae that serve as direction finders respond to the seductive odors and fly toward their sourc'e. Even if they receive no moxe than a lingering trace from an empty box in which a female has been confined, off they go. Males liberated three miles away from a female have been known to find her, although only virgin xnoths can cast their spell in this way. It is language of a sort whether or not it is consciously transmitted and received, for a message is conveyed with all the compulsion of a command.
In this sense the frog calls that enliven the swamps and ponds of springtime, from the deep bass grunt of the bullfrog to the piping of the spring peepers, are all calls of identification serving to bring males and females together at a time and place suitable for propagation. And when so many kinds of frogs and toads inhabit the same general region it is important that the call of each may be clearly recognized by those for whom it is intended.
The calls of twenty-six fx*ogs and toads have recently been studied by means of a sound spectograph, an instrument developed by Bell Telephone Laboratories for the visual investigation of human speech. The various sounds are converted into pietui-es, called spectograms, which show that each has a pattern of its own. Some of the tree toads, for instance, produce a call similar to a human yodel, and others a call which pitches downward to give a melancholy sound. The whole of the sound spectrum seems to be exploited with each species assigned its own narrow band of wavelengths. And while the ear of a frog may respond to the whole range, the brain of the female frog is deaf to all but the notes of her own particular brand of lxiasculine glamour.
Perhaps fisli have their language too. Many anglex-s are convinced that when a trout rises to a fly and gets away it somehow commuxiicates its experience to every other trout, in the pool. This may be so, for stranger things have happened, or it may be no more than a good alibi. Catfish, which only a boy would care to catch, do have a voice inasmuch as they have an open duct connecting their aixbladder with the throat and can grunt to one another through the muddy waters they inhabit.
But most fish, including trout and catfish alike, have chemical senses far beyond our comprehension, and who knows what tasteful messages pass froni one to another? For we each live in a world which is peculiarly our own and communicate among oui-selves as best we can with the equipment with which we are each endowed. +