Old dogs and new tricks
While baby animals are particularly eager and able to learn, and while there are many things it’s harder to learn as you get older, animals do keep learning. New neural connections are formed, new ideas are received, and new behaviors are exhibited. It’s never too late to learn that a certain individual bites. You are never too old to learn that a particular food can make you sick.
Bluntnose minnows were taught to distinguish between water from Honey Creek and water from Otter Creek. Going to one kind of water brought a snack, going to the other produced an electric shock. Aged bluntnose minnows, nearly two years of age, “approaching senescence,” learned this task as well as yearlings. Yearling minnows remembered the difference between the two creek waters for 15 weeks, however, whereas ancient minnows remembered for only 6.
Clarence, the house sparrow hand-reared by Clare Kipps, lived to a remarkable old age. At two, he had a stroke. He couldn’t fly anymore, being unable to coordinate his wings. His balance was off, and he kept falling onto his back, calling “quite cheerfully” for Kipps to come and put him on his feet. Eventually he discovered that he could get back on his feet by doing a flip, “becoming so expert that before long he could leap instantaneously into the air from his inverted position, turn a complete somersault and come down the right way up—surely a feat for a small bird even in the first blush of youth!” (The adult chimpanzee MacGregor learned to progress in somersaults after he was crippled by polio.) The lack of coordination also made it hard for him to hop with both feet, as sparrows customarily do, and to the astonishment of ornithologists Clarence took up walking, right, left, right, left, just like the rest of us.
Innovation builds on learning. Sometimes an animal simply does everything it can think of with a stick and notices—learns—that one thing produces good results. At other times an animal learns in the same way what sticks can do and then thinks of a way to use that. If we could break intelligence in two, the ability to learn might be one part, and insight, leading sometimes to innovation, might be the second part.
EIGHT
How to Get Cultured
In Laguna, Brazil, people and bottlenose dolphins fish cooperatively. Fishermen with circular throw nets stand in a line, waist-deep in shallow water in the town’s lagoon. The water is brackish and murky. A few dolphins drift slowly along the line a few meters away, facing seaward. Occasionally a dolphin signals by arching its back, slapping the water with its head, and then slapping the water with its tail as it dives. The dive roils the water, and the fishermen cast their nets into the space between dolphins and people, onto schools of mullet, croaker, or black drum. Those who catch fish carry their nets up to the beach and other fishermen take their place in line. Meanwhile the dolphins grab the fish who race out from under the net.
The fishermen can’t see the fish, and only know when to cast nets by watching the dolphins, who herd fish toward the beach. As for the dive, “the timing of the dolphin’s roll indicates that fish are present; the direction of the dolphin’s movement indicates the location of the fish, and the vigor of the movement appears to indicate whether the school is large or small: the dolphin may show the head, back and dorsal fin, or just the head or blowhole.” The falling nets presumably cause some fish to dash straight into the dolphins’ jaws as they duck the nets. One dolphin may work the line for a couple of hours before leaving, and it is often replaced by another dolphin.
The fishermen do not feed, signal to, or train the dolphins. The dolphins—who can detect the fish—are in charge. If a dolphin moves to another part of the beach, fishermen hurry to follow. Sometimes people wait on shore, hoping a dolphin will show up. Dolphins spy-hop (stick their heads above water) to see if there are people ready to fish.
Researchers estimate the local dolphin population at 200, and 20 to 30 dolphins participate in the cooperative fishery. This is serious business, the primary source of income for about 100 families who sell the fish in nearby towns. On one day during fishing season, researchers saw six dolphin-human groups fishing in the lagoon, with up to 3 dolphins and from 4 to 40 men in each group.
Male and female dolphins both take part. Calves accompany their mothers. Some of the calves of cooperative fishers join in and some don’t, but apparently no dolphins join who don’t have a mother who was part of the fishery. At Imbé, 200 miles to the south, researchers saw the dolphin Geraldona and her four-month-old calf taking part in such a fishery. Twice, as Geraldona signaled to the fishermen, the calf followed behind her. The next three times the calf swam by her side. Finally Geraldona hung back as the calf went forward by himself and signaled the fishermen, who took his advice and netted mullet.
Rarely, a dolphin cheats by lifting or reaching under a net to grab entangled fish. The fishermen, alerted by mud clouds, throw sand or rocks at the dolphin to chase it away.
Laguna town records indicate that the dolphin-human fishery began in 1847, and some fishermen say their fathers and grandfathers fished with dolphins before them. That generations of dolphins participate is shown by Chinelle, a dolphin who has at least two daughters who are also active in the fishery, one accompanied by her calf. How the tradition started is a mystery. There are four such known fisheries in southern Brazil and scattered reports of similar fisheries around the world.
PEOPLE HAVE ELABORATE CULTURES, with enormous stores of learned information. In its everyday definition, culture includes language, religion, musical styles, ways of dressing, how to use tools and technology, rules about what parts of the body clothing should cover, styles of child-rearing, rules about who can marry whom, ideas about what people can eat and what they can’t, and more. We use the word “culture” to refer to things as immediate as how closely you should stand to another person and as abstract as whether religion should be part of politics.
The essence of culture is learning from others. Animals, like people, behave badly often enough that it hardly seems likely that they would refrain from stealing each other’s ideas. Yet there is, inevitably, debate over whether any animals really have culture. This begins with debate over what culture is exactly. (Ethologists traditionally speak of traditions, rather than culture.)
Some scientists define culture simply as the nongenetic transmission of behavior. In The Ape and the Sushi Master, Frans de Waal writes, “Culture is a way of life shared by the members of one group but not necessarily with the members of other groups of the same species. It covers knowledge, habits, and skills, including underlying tendencies and preferences, derived from exposure to and learning from others.” Just how animals learn from one another is unimportant in de Waal’s definition.
Other definitions are more exacting. Some cultural anthropologists take the view that there is no culture without language. Among the criteria that culture should show, as proposed by W. C. McGrew, are innovation, dissemination, durability, standardization, diffusion, tradition, nonsubsistence, and naturalness. Yet we can easily characterize some human cultures (other human cultures, naturally) as being anything but innovative. Using these criteria, it has been argued that chimpanzees show no cultural behaviors. Nor would the dolphin-human fishery described above qualify as a cultural behavior for humans or dolphins, since it involves subsistence—getting something to eat.*
Michael Tomasello is also strict about what he considers cultural behavior. In his definition, it must include imitation, and we know how long the arguments about that go on. With fairness, Tomasello comments, “Although I have expressed doubts about the facile use of the term ‘culture’ with respect to chimpanzees, in very few cases has the behavior of human children been examined with the skeptical scrutiny I have used in this analysis.” Preferring to think that some animals and some humans do in fact show cultural behavior, I will, like de Waal, use a broader definition of culture espoused by many researchers, including pioneering Japanese primatologists like Shunzo Kawamura and Kinji Imanishi.
The wisdom of the ancients
Cultures pass o
n information that has been learned, not just to the children of the learner, but to other members of the group. Some social animals benefit from having knowledgeable elders, who are not necessarily leaders. Primatologist Hans Kummer, following hamadryas baboons in Ethiopia, noticed that the aged and no longer dominant baboon Admiral knew the best routes across every obstacle and exactly where to dig for edible roots. Younger animals worked harder and found less. One afternoon the troop had not drunk all day. They were walking down a dry riverbed when Admiral, ahead of the troop, veered off to climb a bare hill with a patch of shrubbery on top. As he made his slow way up, he was passed by a juvenile and a female who went past the bushes. Admiral entered the bushes, and they turned back. In ones and twos, the entire troop went in. Afterward, the researchers found that in the middle of the bushes was a shaded hole in the granite, a yard deep, with a pool of rainwater at the bottom. Admiral knew it was there, but at least some adults did not.
In Amboseli National Park, Kenya, matriarchs are valuable assets to elephant herds. The older the oldest female, the better the herd’s reproductive success. Perhaps she is better able to lead them to food and water. She also knows everybody. When elephants hear the contact call of a strange elephant, they bunch up protectively and wave their trunks around trying to sniff out the identity of the stranger. Scientists tested the reactions of herds in Amboseli whose matriarchs’ ages ranged from 27 to 67 years old by playing them recordings of the calls of different elephants in the park. Herds with older matriarchs were far less likely to get panicky and go into defense mode, because the matriarchs knew the calls of more elephants. Herds with younger leaders spent more time fussing and worrying about invaders than in eating.
Short-finned pilot whales reach at least 80 years old but don’t breed after 40. Jared Diamond reports seeing a 55-year-old killer whale with his 85-year-old mother. That females do not simply die when they become menopausal suggests to researchers that they are making valuable contributions, and perhaps part of that is knowledge.
Cultural hotbeds
In looking for conditions that might favor the development of culture or “proto-culture” in chimpanzees, Sue Taylor Parker and Anne Russon point to cognitive abilities such as imitation, the ability to teach by demonstration, and the social trait of female dispersal. If babies mostly learn from their mothers, then in a species in which females move from one group to another, they will carry traditions to the new group. (In some animals, females stay put and males move to new groups.) That chimpanzees use tools to get at recalcitrant foods such as termites, ants, and nutmeats also favors apprenticeship in tool use.
Duane Rumbaugh, Sue Savage-Rumbaugh, and Rose Sevcik, who have studied symbol and language acquisition in bonobos, chimpanzees, and children, note that young animals sometimes learn rapidly to do things their elders have laboriously struggled to master. Learning things in childhood may sometimes help develop “cognitive structures” in the brain of the young animal. Their improved performance could lead to a more focused learning experience for their own offspring. “Cultural gains might have been made indirectly and quietly as each gain, in turn, served to direct cognitive development of the ever-observant child to specific topics for reflection and refinement as he or she matures. Thus, the bedrock for geometric gains in building culture and technology across eons was laid in the minds of babes.”
The arts, theater, and the dance
To some people culture means museums, symphonies, ballet. Some animals have musical and even artistic traditions. These can be passed on vertically, from parents to children, or vertically, horizontally, and obliquely. The striped-back wrens of Hato Masaguaral, Venezuela, have been studied since the 1970s by biologists who chart their genealogies. Striped-backed wrens live in family groups consisting of one breeding pair and as many as 12 of their children from previous years. Together the family maintains their nest, feeds new babies, and patrols their territory, an area of about an acre. Young males usually stay with the family for their whole lives, and may inherit the territory one day, although sometimes they strike out to find a new territory. Young females leave, often with their sisters, and look for a new family to join.
These are talkative birds. All the wrens utter nasal, raspy, clicky calls that sound to English speakers like a drawled “Where are you?” WAY, for short. They WAY back and forth all day. Males have a set of about 12 WAY calls, and females have about 4. Each family’s males and each family’s females have a set of WAY calls that are completely different from the WAY calls of the wrens in neighboring territories. Researchers suggest that during territorial disputes, WAY calls help birds keep track of which team is which.
Striped-backed wrens learn their WAY calls mostly vertically—young females learn from their mothers, and young males learn from their father and brothers. Young birds copy the songs of their elders with great fidelity. When researchers found two widely separated groups where the males had very similar WAY repertoires, they went to their genealogies and discovered that the two groups had a common great-grandfather, who had died two decades before, but whose songs his descendants still sang. He had left one family group to join or found another, and took the family songs with him.
Busy designer/architect/painter/musician/dancer wishes to meet females, LTR not desired
A male satin bowerbird doesn’t fully develop his maddeningly attractive deep blue plumage until he is six or seven years old, but in the meantime a young bird is not just playing video games. He builds practice bowers—courtship sites—of increasing sophistication and grandeur. He goes around to the bowers of impressive older males and views their displays. Satin bowerbirds make very impressive bowers, even for bowerbirds. A male clears a space for his court and builds a broad platform, on top of which he builds an avenue of sticks. He decorates this with attractive objects, especially blue objects, since satin bowerbirds adore blue. (In addition to the male’s indigo suit, both sexes have Elizabeth Taylor blue eyes.) Other favored accents include yellow leaves, yellow straws, blue and yellow flowers, snail shells, and shiny cicada shells. Parts of the bower are painted with paint the male mixes by chewing up vegetation with plenty of saliva. He also prunes the foliage above his bower so that shafts of light illuminate his artwork.
A male bowerbird displaying stands on his platform, often holding a priceless object of art in his bill, such as a blue feather. He faces his audience. He whirrs and prances. He fluffs his feathers and calls, flapping his wings to the beat of his call. He ornaments this song with chortling, buzzing, mimicry of other birds and environmental sounds, and tasteful interludes of silence.
Awestruck, a young male viewer goes back to his bower and practices his own song-and-dance routine. If he happens to visit the impressive bower of an adult male when that male is away, he may act as if it’s his own bower: do a little painting, practice his display, or even put the moves on any female who drops by.*
A nice bower is key to social success. Some males do not get to mate all season, but one male observed by Gerald Borgia and colleagues mated with 33 females. (Sadly, photographs of his bower, which must have been stunning, do not seem to be available.) The researchers ranked bowers for quality and found that their ratings agreed with those of female bowerbirds: bowers should be symmetrical and neat, sticks should be densely packed, and the general appearance should be highly sculptured. Also, females seemed to feel bowers should have plenty of knickknacks, especially blue feathers.
Blue feathers are in short supply, and the most efficient way to get them is to steal them from other bowerbirds. A desirable blue celluloid band changed ownership several times a day until one bird wove it into the bower itself. Researchers got involved in this illicit traffic, but if they purloined feathers from popular, dominant males and put them in the bowers of nobodies, the feathers were stolen right back, and the status quo did not change. Thus, the most successful males are thieves who have too much clout to be stopped. This correlates with age. “Older males maintain bowers of better
quality and decorate them more elaborately, and they are more successful in protecting their bowers from destruction. Moreover, older males give more refined courtship calls,” writes Borgia.
Vogelkop bowerbirds are dowdier than satin bowerbirds, and they build elaborate decorated huts around saplings. They are hard to study because they live in remote mountain areas of New Guinea that are logistically and politically difficult to get to. Jared Diamond discovered that two populations of Vogelkop bowerbirds that look identical build distinctly different bowers. In the south Kumawa Mountains they glue together tall towers of sticks, which rest on circular mats of moss painted dead black, decorated with somber snail shells, stones, and acorns. In contrast to this gothic look, Vogelkop bowerbirds in the Wandamen Mountains make low, woven towers covered by a hut with a doorway, all resting on a mat of green moss adorned with colorful flowers, fruit, and butterfly wings. Diamond tested whether the birds in different areas decorated differently because they had different objects available to them. He offered the two populations identical arrays of poker chips in red, orange, yellow, blue, purple, lavender, and white, laying them on the mats of the bowers.
In the somber south Kumawa Mountains three out of five birds took the poker chips and dumped them in the woods. The other two birds, SK1 and SK5, were known slobs who never bothered to take fallen leaves off their mats, and they ignored the poker chips. In the gala Wandamens, birds dumped some chips and kept others, arranging them attractively in their bowers. While their preferences were not identical, all birds liked blue chips best and white chips least. Purple was the second most favored color, followed by orange. Meanwhile the adult birds busied themselves stealing each other’s chips, first the blue, then the purple, then the orange. When they weren’t stealing from each other, they went after Diamond’s yellow film boxes, blue matchbox, and black camera. W9 had a try at stealing another researcher’s blue sock and brown shoelace while they were still on his foot.
Becoming a Tiger: The Education of an Animal Child Page 30