“I was in a state of disbelief,” Savage-Rumbaugh writes. She had to rearrange her thinking. She went back through two years of notes, trying to figure out when Kanzi had learned what no one had taught him. Kanzi was not calm enough to sit still to take a blind test and he didn’t like to answer questions. That would have to come later. “From the moment the enormity of what Kanzi had done became clear to me, I knew that I would not be believed,” Savage-Rumbaugh writes. She must have had the specter of Clever Hans peering over her shoulder.
Wisely, they decided not to give Kanzi the planned tutorials, but instead to interact with him through lexigrams and their own spoken English, in activities that would interest him. This turned into a sort of wilderness camp, with researchers spending their days walking and playing with Kanzi in a 50-acre forest adjacent to the laboratory. Soon Kanzi knew 256 lexigrams—in fact, he knew more, but the board would only hold 256 at a time.
Kanzi uses simple rules of syntax, using word order to specify who should chase whom, for example. Conversing with lexigrams is limiting, so researchers looked at how well he understood the syntax of what people said to him. They gave him wacky requests, so he couldn’t guess what was wanted. “Would you put the grapes in the swimming pool?” they asked, and he got out of the pool, found the grapes, and tossed them merrily into the pool. Still warding off Clever Hans, Savage-Rumbaugh sat behind a one-way mirror and asked Kanzi to “put the chicken in the potty.” Everyone else present wore headphones so they couldn’t hear Savage-Rumbaugh and inadvertently cue Kanzi, who was busily putting the chicken in the potty. His actions showed that he understood the difference between “Pour the Coke in the lemonade” and “Pour the lemonade in the Coke.” “Go vacuum Liz,” “Go get the noodles that are in the bedroom,” “Knife the doggie,” suggested Savage-Rumbaugh, and Kanzi vacuumed Liz, fetched the noodles, and knifed what I am sure was a toy doggie.
Kanzi is good at phrases like “Get the ball that’s in the cereal,” which might be expected to be hard, because they contain an embedded phrase (“that’s in the cereal”), but terrible at even short lists like “Show me the milk and the doggie.” He is apt to produce either the milk or the doggie, but not both. While Kanzi’s comprehension of English and English syntax is imperfect, it casts doubt on the proposition that language is an all-or-nothing affair, possessed in its entirety by humans and not at all by any other species.
Like a young bird singing subsong or Alex babbling in the evenings, Kanzi talks to himself. He takes the keyboard and moves away from the group. “If I try to look over his shoulder to see what he is saying, he generally picks up the keyboard and moves further away.”
Ai and Ayumu
Ai (pronounced eye) is a chimpanzee at the Primate Research Institute of Kyoto University in Inuyama, Japan. Tetsuro Matsuzawa and colleagues have spent two decades teaching Ai to communicate through symbols. She touches letters and numbers on a computer terminal to receive tokens she can put in a vending machine to buy snacks. She understands about 30 words in spoken Japanese. She lives with other chimpanzees, and in 2000 she gave birth to a son, Ayumu. Naturally she carried him everywhere she went, including to classes.
In February 2002, Ayumu, not quite 10 months old, suddenly decided to operate the computer himself. While Ai was off using the vending machine, Ayumu touched the start symbol on the monitor and, when the computer screen displayed the Japanese kanji symbol for brown, touched the kanji. When the computer displayed a brown square and a pink square, he touched the brown square. He had to stretch, because the brown square was above the pink square and he was still a very small ape. He had to stand on the tray under the monitor, and on his third attempt he reached the brown square, winning a 100-yen coin. This was the first time he had ever touched the computer screen.
No humans were present when Ayumu made his move—a video camera recorded the events. It’s too soon to know how much Ayumu will pick up from what Ai is being taught. Like the children of immigrants who effortlessly acquire skills their parents had to toil long and hard to acquire in imperfect form, Kanzi and Ayumu make things look easy.
“The first two years of an ape’s life are something of a magical time,” write Sue Savage-Rumbaugh and Roger Lewin. “During this period, if exposed to brightly colored geometric symbols, apes learn to tell them apart as easily as if they were looking at different kinds of food. If exposed to human speech, they become responsive to the phonemes and the morphemes so that spoken language no longer sounds like a string of noises. If they watch television, they come to see the patterns on the screen as representations of other people and other apes in different places, rather than just flickering images.”
Cat got your tongue?
Many scientists have expressed puzzlement at the fact that captive apes have the ability to learn and use elements of human and artificial languages—and yet wild apes simply don’t seem to do much of the sort. Why would they have a capacity they don’t use? Primatologists often seem to regard the vocal achievements of birds with restless envy and incomprehension. Birds! With tiny bird brains! How can they learn to do all these things that my apes can’t do?
Christophe Boesch has suggested that chimpanzee language abilities “are present in the wild but have yet to be discovered.”
Charles Snowdon and Martine Hausberger write of scientists fretting that there is “little evidence of vocal plasticity in nonhuman primates, suggesting a gap in continuity of developmental processes in the evolution from birds to humans.” But when vocal learning is understood to include not just learning to make sounds, but also learning to understand sounds and learning when to use sounds, they suggest, “there is no ‘gap’ between birds and humans.” In other words, ape and dolphin vocal learning, even though it doesn’t involve much making of sounds, is sophisticated enough to form part of a spectrum between sparrow song and ridiculously complex human language.
Nonvocal communication
Perhaps we should be looking at the areas where we ourselves are not the stars—at nonvocal communication. Many animals, from dogs to captive apes, are disturbingly good at reading the emotional states of humans, for example.
In the wild, understanding the alarm calls and actions of other species increases animals’ ability to gather information. The authors Anup Shah and Manoj Shah describe how, if a grazing chital deer looks up and sees a sambar deer peering into the foliage, it will stop grazing and try to spot the possible danger. Primatologist Thelma Rowell describes a patas monkey standing in tall grass peering at a possible threat: the other patas stand and, following the first one’s gaze, peer too. Vocal communication—the alarm chirp—comes if there is a greater sense of threat. (If a predator is seen, the adult male of the troop will bounce up and down while making a loud racket as he retreats, while the women and children sneak silently away. This is very noble of him, and if he doesn’t do a good job, the females kick him out and get a new male.)
Where do you want to meet for lunch?
In Ethiopia, hamadryas baboons sleep on cliff faces where they are safe from predators. In the morning they descend and sit around before breaking up into smaller groups. Around midday the groups meet at one or another place where there is water, and then separate again to meet at the sleeping cliffs at night. Researchers tried to figure out how the baboons managed to meet in the middle of the day. Careful observation revealed that in the morning the male baboons who lead their groups make a series of very short forays in the direction of watering places. Then they pause to see in what directions other males make forays. Having seen this, they may change the direction of their next symbolic foray or they may continue to insist on the direction they first indicated. Eventually they reach consensus and break up into their separate groups, going in separate directions for the time being, but knowing where to meet at noon. Old males, who are not the highest ranking, are the most influential in swaying other baboons to go in the direction they select. Ethologist Hans Kummer writes, “The hamadryas cannot point out thi
s direction to one another, so at the beginning of their march they must ‘walk it’ for a while, even though immediately afterward they may branch off toward closer destinations in other directions.”
Pointing
Pointing is a notable form of nonverbal communication that seems obvious to adults. A very small child or an inexperienced dog, seeing a person point, will look at the finger and not at where the person is pointing. Most dogs readily learn to look in the direction of the pointed finger. Small children not only learn what pointing means, but begin pointing to things themselves to make their wishes known. In fact, a small child often personally invents pointing to orient her-or himself toward an object. When the child wants to draw someone else’s attention to an object, he or she will typically perform “gaze alternation,” looking back and forth between the object and the person who ought to be looking at the object.
It has been suggested that this kind of pointing, “referential pointing,” is the exclusive skill of the most winsome species ever to inhabit this planet: us. Primatologists leaped in, with evidence that captive apes and monkeys perform referential pointing, complete with gaze alternation. But maybe that’s just from hanging around with us?
The orangutan Chantek pointed early and often, indicating things he wanted to be given, directions in which he wanted to be carried, spots where he wished to be tickled, and places he wished others to go. Kanzi, the bonobo, started pointing to indicate where he wanted to be carried when he was less than a year old, but Sue Savage-Rumbaugh notes that most primate infants can’t do this, because they need their hands to cling to their mothers. Later Kanzi used pointing eloquently, pointing to a caretaker’s pocket that held keys, to the lock on the door, and then in the direction of the room where he wanted to go once the door was unlocked.
In the Ikela region of Zaire, a wild bonobo spotted danger lurking concealed in the surrounding foliage, which the other members of his group had not noticed. He screamed and pointed to the two spots where menace lay hidden, using his right arm and folding back all but two fingers. He alternated his gaze between the peril and the other bonobos. The others approached him, looked where he was pointing, and beheld the horror: two ghastly groups of primatologists, feverishly making notes on his spectacular ability to communicate by pointing.
Beyond pointing, there are other gestures, more arcane in their meaning, that bonobos and chimpanzees have devised. Austin and Sherman, lexigram-using chimpanzees, used a special hand clap to indicate that they wanted to play a chasing game, and the younger Kanzi learned this from watching. He watched wistfully, because the big boys were having too much fun to play with him. He was one and a half, and it took him two days of practice to master the gesture.
An entire set of gestures used by bonobos has gotten little attention. These primates have recently become renowned for their active, cheerful, promiscuous sex lives. In the 1970s, when these apes were little known, a group of three wild-caught bonobos was observed at the Yerkes Primate Center. It was noticed that they frequently gestured, and that these gestures related to one of their big interests: sex. Analysis of the gestures that the three used before sex showed that they had an impressive array of mutually understood signals. The 21 gestures defined almost all had to do with positioning. A series of photographs in the scholarly publication reporting this shows a male bonobo making eye contact with a female and negotiating with her about positioning. She indicates interest but does not accept his initial suggestions about position. He makes an alternate suggestion and she agrees.
The researchers describe the way some of these gestures become abstracted. In a first-order gesture, to take a fairly clean example, a bonobo might push another bonobo under the chin to persuade the partner to stand bipedally. In a second-order version of the gesture the bonobo would touch the chin and then lift her hand upward. In a third-order version she would just raise her arm and flip her hand upward at the wrist.
Fingers? Who needs fingers?
Bob and Toby are two bottlenose dolphins at Walt Disney World who were being trained to interact with scuba divers via an underwater keyboard. After six months, Bob and Toby became more assertive, using the keyboard themselves (rather than simply responding to human use of the keyboard) and then looking at the humans “as if to monitor the human’s response.”
They also invented pointing, to the surprise of the humans. To point at a food container, the dolphin would stop swimming to hang in the water, and “align the anterior-posterior axis of his body with the object for several seconds.” In other words, he’d hold his body straight and point at the object with his whole body. He’d then look back and forth between the container and the trainer. If he was lucky, the trainer might then swim up, take a herring out of the container, and hand it over. On a few occasions Toby appeared to be pointing for the benefit of the person running the underwater video camera, judging from the direction of his gaze alternation. (“Be sure you get this! Here’s me, pointing. Are you getting this?”)
The dolphins didn’t bother to point if there were no humans around to respond. The researchers speculate that dolphins don’t point among themselves because they can monitor each other’s sonar attention. Pointing was a hint to sonar-blind humans.
I swear that dog is reading your mind
Dogs are good at understanding human messages, both deliberate and inadvertent. In many tests they do better than nonhuman primates at figuring out which of two boxes has food hidden in it, when a human knows the answer. They notice the orientation of the person’s head, or the direction of the person’s gaze, and easily grasp signals such as tapping on one box. As already noted, they catch on quickly to pointing. Trained gun dogs do better than pet dogs, and untrained gun dogs do better than untrained dogs of other breeds. Wolves do terribly.
Translation
Leo, an orphaned lion raised by a game warden’s family in South Africa, loved to go for walks and loved riding in the truck. He could not discern between the words “walk” and “drive,” so whenever someone suggested either, Leo would light up with excitement and gaze at his hero, the dog Wolfie. Wolfie knew the difference and would either jump in the truck or head for the gate. Whatever Wolfie did, Leo would do.
Whenever the family wanted to instruct Leo they’d tell Wolfie. If Wolfie sat, Leo sat. Wolfie, a conscientious Australian cattle dog, not only understood what people wanted him to do, he understood that Leo did not understand, and that it was his job to make Leo understand. Kobie Krüger, Leo’s foster mother, writes, “If Leo wasn’t paying attention, for instance, Wolfie would have to repeat the required action several times until Leo got the message.” What a good dog.
We humans still win dramatically when it comes to vocal and verbal learning. We read and write, for heaven’s sake. We sing songs with lyrics. But other animals turn out to be doing a lot more vocal learning than we knew, particularly when we examine what they understand as well as what they say. As the secret learning of Ai and of Kanzi, and the isolated learning of Alex among all grey parrots, show, we’re still floundering beginners at teaching communication to animals. We’re also making discoveries (hummingbird vocal learning, bat vocal learning, dolphin signatures, kangaroo rat signatures, and more) at such a rate that there must be even more exciting news in store.
FIVE
How to Make a Living
Captive-born tigers want to hunt and they have ideas on how to go about it, even if they lack practice. It is certainly unwise for mice or birds to wander through a tiger’s cage. “They’ll catch anything that tries to come in,” says tiger expert Ron Tilson.
At the Minnesota Zoo a small flock of wild turkeys wanders the grounds. They find the zoo a charming habitat and view the humans who infest it with only mild concern. There’s food for the taking in many of the enclosures, and the crowds of people keep most turkey predators away. Tilson, observing the tiger exhibit one morning, saw the turkeys strolling there just as a couple of two-year-old tigers were released from their nighttime q
uarters.
When one of them spotted the turkeys he knew just what to do, Tilson relates with pride. He crouched to the ground and crawled on his belly toward the clueless turkeys. The tip of his tail twitched. He placed his feet just as a wild tiger does—each hind foot set down exactly where a front foot was a moment before. When he was close, he rushed the startled turkeys, who flew up into the trees. But in the panic, one turkey didn’t find a clear flight path, hit the fence of the exhibit, and bounced off. The tiger sprang into the air, also hitting the fence. Tilson was able to measure a spot where the tiger’s belly had hit the fence, 10 feet off the ground. (You can visit the zoo safely: the fence is 20 feet high.) However, the turkey got away. “It just missed him!” Tilson says. One presumes the turkeys learned something that day.
A tiger with more practice might have been able to catch that turkey. In fact I can’t help feeling, in species vainglory, that you or I might have caught one of those turkeys. But other hunts in the tiger enclosure have been more successful. One year a mallard duck elected to build her nest by the moat in front of the tiger exhibit and hatched a dozen ducklings. Some visitors who saw the brood dwindling day by day were upset by this evidence that the tigers had not lost their predatory nature, and complained bitterly to zookeepers. I myself have criticisms for the duck.
IT’S ALL VERY WELL to learn who you are and what to say about it, but it’s even more vital for baby animals to learn how to make a living when they grow up. Some professions, such as eating grass, don’t seem to require as much learning as other professions, such as sneaking up on, killing, and eating grass-eaters. On the other hand, to succeed at the job of eating grass, you must also be able to avoid those who would end your career by eating you.
Becoming a Tiger: The Education of an Animal Child Page 17