With this in mind, the condor species recovery team released AC-8 in April 2000. AC-8 (short for Adult Condor 8) was born in the wild—no one is sure when—where she grew up. In 1986, with the species on what looked like its last legs, AC-8 was captured. (By 1987 there were no condors left in the wild. All living birds were in captivity. Releases of captive-reared birds began in 1992.*) Under the auspices of the U.S. Fish and Wildlife Service, AC-8 produced 12 chicks in the next 14 years, many more than she could have raised in the wild, since condors do not breed every year. She also spent time with the young condors raised in captivity, since staffers hoped she would be a mentor to youth and that they would imprint on her. (The condor keepers didn’t call her AC-8, but Grandma.) Eventually she stopped laying fertile eggs. At the time of her release, her age was guessed to be between 28 and 40. She was released together with two captive-reared 10-month-olds, in Ventura County. She flew 80 miles to her old foraging range and settled back into the old life. Whether any of the young condors modeled their ways on hers is unclear. Just three years later, a participant in the Tejon Ranch Company’s annual Pig-O-Rama pig hunt spotted AC-8 sitting in a tree and shot her.
Orangutan lessons
The issue of rehabilitation and culture is clearest with orangutans. While the biggest threat to the species is loss of habitat, the large reddish apes are easy to shoot from trees. There is a lucrative illegal trade in baby orangutans (for pets), which are obtained by shooting their mothers and hoping the baby is not killed in the subsequent fall. As a result, there are two kinds of orangutans needing rehabilitation: infants and older apes who have been confiscated from the black market by law enforcement; and former pets who have grown too big, too old, too destructive, and, in some cases, too obviously lustful for the families who originally purchased them. Some of the former pets miss their favorite television shows. Others probably do not miss being chained under the house for years.
In rehabilitation programs run by scientists Willie Smits or Biruté Galdikas, orangutans have a chance to learn survival skills that will fit them for life in the wild. “Most people think that if you let an orangutan loose in the forest, it will know what to do naturally,” scientist Robert Shumaker told the Smithsonian. “That is wrong. Orangutan juveniles aren’t genetically programmed—they must be taught about their environment, just like humans.” Shumaker studies cognition in the orangutans at the National Zoo, and hopes that understanding how orangutan minds work will help rehabilitators give the apes the skills they need. Ordinarily, they learn while spending years in the company of their mothers. That it can be done by humans is shown by the case of Uce, the first infant Smits rehabilitated. She was offered for sale in a Bornean market, but there were no takers because she was visibly ill. Smits found her crate discarded on a garbage heap, with the dying infant inside. He nursed her back to health and spent years with her while she learned to live in the forest. At last report Uce was living in the Sungai Wain Forest, and when visited by Smits, she climbed down from the trees to show him her baby, Bintang.
As researcher Anne Russon notes, rehabilitant apes must not only learn a set of skills for wild life, they must also unlearn things that were useful to them in captivity, such as getting food from people. Teaching orangutans to locate, prepare, and eat forest foods is a challenge for people who don’t eat those foods themselves. Knowledgeable orangutans who are willing to be role models make much better demonstrators. With no one to show them a better way, some of the naive orangutans adopted inefficient or useless foraging techniques. Judi ate ants one at a time, pinching them up between thumb and forefinger, whereas wiser animals mopped up a bunch of ants on the back of their hand and then licked or sucked them all off. Tono, aware that termite nests (these are spongy nests built in trees, unlike the earth nests that chimpanzees exploit) contain savory termites, tried to open them by banging them on hard surfaces, which worked exactly never. Yet he persisted for months, once trying to break one open on Aming’s head. The nest didn’t break, and Aming took it badly.
Adapting to the forest is hard, and some orangutans in rehab have been known to wait at bus stops on roads through the forest and climb aboard looking for an easier life. Others tough it out: Judi eventually learned to eat ants by the handful.
Enculturation
Animals raised by people, particularly great apes, are sometimes called enculturated animals. They have been raised in our culture, not their own. Anne Russon considers some of the orangutans at Galdikas’s Camp Leakey bicultural—they can survive in the forest and are also at ease in camp among humans.
Some scientists are interested in enculturation as a process that may change what great apes can do cognitively, and others also focus on how enculturated apes are entitled to be treated. Lyn Miles calls Chantek her foster son. She rues the fact that “our society isn’t prepared for dual-culture creatures” and hopes that someday Chantek can have a home with other enculturated apes, an environment “featuring agency and choice,” one where he would have companions he could sign with. Perhaps he will be able to go to an ape preserve in Maui, Hawaii, now under construction by the Gorilla Foundation as a place where Koko and other gorillas can live.
In one experiment focusing on enculturation, human two-year-olds, chimpanzees raised like human children and “exposed to a languagelike system of communication” (lexigrams), and chimpanzees raised by chimp mothers were given a chance to imitate a demonstrator. The human toddlers and the chimp raised by humans both copied the human demonstrator, and the chimpanzees raised by their mothers scarcely did at all. Based on this, Michael Tomasello asks which group is likely to have intellectual abilities most like wild apes—the captives raised by their mothers or the enculturated chimpanzees? His hypothesis is that “a humanlike sociocultural environment is essential to the development of humanlike social-cognitive and imitative learning skills.”
Frans de Waal takes a different view. The experiment shows that chimpanzees can imitate as well as human children when the model is a species they have grown up with, he suggests. He suspects that imitation is important to wild chimpanzees, and that this ability is useful in their natural lives. It’s not that enculturated chimpanzees have become smarter, better imitators from being around us, but that they accept us as part of their community. “Rather than having been lifted to unprecedented cognitive levels, apes raised by people have become ideal test subjects simply because they are willing to pay attention to psychologists.”
The chimpanzee Jun, in the Tama Zoological Park in Tokyo, was insultingly uninterested in a human demonstrating how to crack walnuts with a stone hammer and anvil, ignoring him through dozens of sessions. But she was instantly riveted by the sight of Sachiko, another chimpanzee, doing the same thing, and took it up herself. Orangutans, too, are far more apt to imitate relatives and friends than they are to imitate strangers.
Wild culture
Christophe Boesch notes that every time the environment of captive primates is enriched, the animals seem to get smarter. But neither a featureless barred cage nor a house with lots of toys and visiting graduate students map directly to the lives of wild chimpanzees. “Not only space and opportunity to explore and play but also the absence of large and complex social interactions have a negative influence on the psychological development of the captive individuals,” writes Boesch. “In my opinion, rules in the wild are more stringent, with survival and reproductive success acting as ‘teachers,’ so that the cognitive development of wild chimpanzees may be more advanced than that of their captive counterparts.”
The shortcut that is culture allows animals to learn things their predecessors have learned without having to take as much time or run as many risks. If they elaborate on that, then, building on the discoveries of earlier generations, animals who are no smarter than their ancestors can live smarter lives.
NINE
Parenting and Teaching: How to Pass It On
At the San Diego Wild Animal Park, zookeepers worried about an unmo
therly gorilla, Dolly. Dolly had been captured in West Africa when she was nine months old and raised at the zoo with other gorilla children and no adults. Her first baby was born when she was 10 years old. Dolly wanted nothing to do with him, although he was a fine healthy baby who tried to cling to her, whereupon she would peel him off. Unhappy zookeepers took him away to raise and named him Jim.
They did not blame Dolly, noting that she had had little socialization, and that “all imported individuals and over 80 percent of infants born in captivity…passed through the critical period of juvenile development in the care of humans. Under such conditions, these infants have been unable to observe and imitate adults of their own species engaging in normal patterns of social interaction.”*
When Dolly got pregnant again, the zoo created a training program “with the specific aim of inducing maternal behavior.” The first part of the program was showing Dolly films “depicting gorilla mother/infant [behavior].” This did not work. Like so many youth, Dolly was unimpressed by educational films and more intrigued by the projector. This is a reasonable intellectual choice, but unless Dolly’s next child turned out to be a film projector, not useful. The second part involved giving her a doll (called a “surrogate infant” in the scientific literature and a “baby” when speaking to Dolly) and teaching her four commands about handling it. Dolly knew the word “baby” from occasions when zoo staff brought Jim over for her to view through the bars. She liked the doll, and when it was offered, she drew it in carefully through the bars of her cage.
Researcher Steven Joines taught Dolly to respond to “Pick up the baby, Dolly”; “Show me the baby, Dolly”; “Be nice to the baby, Dolly”; and “Turn the baby around, Dolly.” This last was aimed at getting Dolly to hold her baby in a suitable position for nursing.
When Dolly’s next baby, Binti, was born, Dolly was an “exemplary” mother, cradling her immediately. The only need for the commands came when Binti, unlike a doll, started to cry. “Dolly did not recognise, and displayed confusion at, the infant’s crying and appeared unable to deal effectively with the situation on her own. However, the command ‘Be nice to the baby, Dolly,’ delivered by a familiar human, soon resolved the confusion.” On command, she cradled Binti to her, and Binti hushed. “Within a week, she no longer required prompting.” Dolly did so well that they gave Jim back to her, and she was a good mother to both.
ANIMALS OF EVERY KIND would become extinct if some of them didn’t produce the next generation. Raising children is literally vital. Like other essential behaviors it is both instinctive and learned.
People sometimes wrestle with the question of whether they can be good parents if their own parents were unsatisfactory, and while it’s clear that a lot of parental behavior is learned at an early age, resulting in the phenomenon of your mother’s or father’s words coming out of your mouth, Dolly’s case is one example of parental behavior learned later in life.
Getting together
Sexual selection, in which animals choose their mates, is a powerful force in evolution. When animals go beyond mating and actually pair off for a season or a lifetime to raise their children, the choice is doubly important. A mate should have good genes, but a spouse should also have good skills.
Many papers have been written about strategies that animals might use to pick a mate. In a paper on mate selection in barnacle geese, Sharmila Choudhury and Jeffrey Black review some strategies. The “random mating” strategy is just what it sounds like—the animal goes for the first possible mate. The “fixed threshold” strategy is to select the first mate who “meets some minimum requirements.” In the “one-step-decision” strategy, the animal decides at each encounter with a potential mate whether to stop looking or keep searching. In the “sequential comparison” strategy the animal also samples prospects but compares each new candidate with the one before. And in the “best-of-N” strategy, the animal compares N potential mates, ranks them somehow, and picks the best one. Peahens use this last method, and I am sure we can all think of people who have employed each of these strategies.
Barnacle geese mate for life, and they split child care, so the mate choice matters. They take their time. In wild flocks, some geese find each other right away, and others go through several trial liaisons before they meet their dream goose. Choudhury and Black raised geese in captive flocks and monitored their romantic lives carefully. In their second winter, the age when wild geese start pairing up, these young captive-reared geese were moved into large enclosures where they could mingle and ask each other searching questions. A male barnacle goose hints that he likes a female by herding her with loud calls and neck stretches. She may encourage this if she likes him, or she may reject him. If things are going well, they’ll stroll, share food, and do triumph ceremonies together. If love derails, it’s easy to tell. “One partner would start to direct threats at the other, respond negatively to or ignore any courtship advances, and/or start courting a new trial mate.”
About half the birds settled down with the first goose they courted, but others went through up to six test geese. Trial marriages lasted from one day to nine months, but a few days was usual. How they made their choices was not wholly clear, although the researchers did their best to figure out what makes a barnacle goose desirable. They rated them on social dominance, weight, facial patterns, and vigilance toward predators. I am happy to state that vigilance was measured by mounting a stuffed fox on a stick and walking it past the enclosure, which caused every goose in the flock to put its head up and stare keenly. Geese who kept their heads up longer were scored as more vigilant. Hoping to get more data, they repeated this test, but the geese had habituated. (It’s the stuffed fox on the stick again. So, are you seeing anyone?) The researchers could not identify any trait that any one goose consistently liked in another goose.
Barnacle geese did not always dump the goose they were courting when they met another goose they really liked. This is referred to as the “partner-hold” tactic and it led to trios of geese strolling around together. This usually didn’t last for more than a few days, but five males were able to form lasting relationships with more than one female. The only noticeable characteristics of these polygamous males was high marks for vigilance. Perhaps they could have protected more than one female from a stuffed fox on a stick.
How did these geese learn who was right for them? Their trial marriages were indistinguishable to observers from marriages that lasted, so what makes one goose lovable to and compatible with another remains a mystery. They did not seem to be using a fixed threshold criterion. Since they never went back to a goose they had previously been with, they were not methodically collecting rankings in a best-of-N strategy. Perhaps 40 percent of the time the geese appeared to be searching by the one-step-decision strategy, trying one goose after another till they found the right one, but about 60 percent of the time they seemed to be using “a modified version of the ‘sequential comparison rule’” by means of the partner-hold tactic. By pairing with two geese at once, they could compare and contrast in a manner that seems obnoxious to me, but if it’s okay with the geese, who am I to interfere?
Make sure she’s a real girl
Speaking of stuffed specimens, a vital step in mating is to make sure that you are directing flirtation at a suitable mate and not a robot or dummy. You thought that went without saying? Ask the lovelorn male corn crakes who were netted while courting a stuffed female. The ornithologists who set up the dummy attracted males by imitating the call of the crake (“crake crake”). Some males who approached the dummy attacked and some courted it, craking, doing an attractive spread-wing display and then trying to mate. One crake made 23 attempts to mate with the dummy, then went away and returned with a green caterpillar, which it politely offered. When the dummy did not take the caterpillar, the crake ate it himself and tried displaying again. The good news for him is that the ornithologists were not netting crakes that day. The bad news is that they were taking pictures.
; Learning to get along, or why cockatiels hate arranged marriages
Cockatiels are in the mating-for-life camp. Unromantic researchers compared the breeding success of cockatiels who were allowed to pick their own spouses with cockatiels who were assigned a mate by researchers. Cockatiels who were allowed to marry for love raised more fledglings. All couples did okay at the first stage of family life, nest inspection. But the “force-paired” couples were less likely to get as far as building a nest in the nest box, and less likely to lay eggs, sit on the eggs, or have the eggs hatch out.
However, if the birds in arranged marriages spent time together before the breeding season, they did better than birds who had been thrown together more recently. This suggests that spending time together helped them get to know one another’s quirks and synchronize their activities better. They still didn’t have the breeding success of birds who chose each other. Pairs of cockatiels who had been sundered by researchers, assigned to other mates, and then reunited after three months had not lost the magic, and were as reproductively successful as they had been before the terrible mix-up.
Becoming a Tiger: The Education of an Animal Child Page 33