Becoming a Tiger: The Education of an Animal Child Read online

  Young condors who were raised by captive condors did much better once released to the wild than those who were raised by puppets. The puppet-reared condors were simply too casual about human beings, even if they didn’t fall in love with them. However, in 2002 a pair of puppet-raised condors successfully hatched an egg in a cave nest. When the chick hatched, the parents were smitten with its charm, and although they had never seen it done, regurgitated food for the chick in flawless condor style.

  Imprinting and international diplomacy

  Another endangered species tale that may involve erroneous imprinting tells of an animal beloved of graphic designers. In the 1960s, almost the only giant pandas outside of China were An-An, who lived in the Moscow Zoo, and Chi-Chi, who lived in the London Zoo. An-An was a male and Chi-Chi was a female. In those Cold War days, it at first seemed impossible that they would ever meet. But obsessed zookeepers pleaded with bemused diplomats and finally arranged for Chi-Chi to visit Moscow.

  Chi-Chi, a surly traveler, was anything but thrilled to meet An-An, and An-An was annoyed to see Chi-Chi. They were kept in separate quarters until Chi-Chi went into heat. Staff from the London Zoo flew to Moscow to be on hand for the historic date. They found Chi-Chi off her food and An-An bleating hopefully through the bars. The next day the pandas were let into the same enclosure. An-An pursued Chi-Chi, and Chi-Chi barked, snapped, and whacked him with her paw. Analyzing film of this encounter, one viewer wrote, “Her actions are those of an animal that does not understand what this other animal is attempting to do.”

  An-An had the idea: sex. Sex with Chi-Chi. Yes. But the idea seemed to shock and revolt Chi-Chi. Sex? Sex with An-An? Never, never, never! Well, maybe—no.

  But she was in heat, and as the hours went by, Chi-Chi showed that she did grasp the idea. Sex. Sex with someone she trusted and respected, someone with whom she had a great deal in common, someone who understood the life of a lonely panda woman. Sex with her keeper.

  Chi-Chi went over to one of her keepers and “presented,” lifting her tail suggestively and backing into him. Far from being flattered, he was in despair. Here he was trying to fix Chi-Chi up with her dream date, the only possible guy outside of China, and here she was making perverted advances to him. Day after day the bamboo bears were put together, and day after day Chi-Chi’s advances to her keepers became more passionate and her behavior toward An-An more irate. Finally Chi-Chi was flown home.

  The zookeepers didn’t give up, and in 1968, An-An flew to London to romance Chi-Chi. He made a prolonged visit, but his persistence was unrewarded. Chi-Chi and An-An are gone and neither of them left a diary, so it’s hard to be certain what went wrong. Some faulted Chi-Chi for being imprinted on humans. Some faulted An-An for not getting tough with Chi-Chi. All schools of thought held that the problem was in their upbringing. Both pandas had been captured as infants and had spent most of their lives without seeing other pandas.

  Chinese panda experts opined that An-An and Chi-Chi didn’t connect because they hadn’t learned how to act around other pandas, let alone how to act when they wanted to mate with another panda. In the wild it is likely that young pandas see adults mating, learning how to act when they are older. To remedy this, the experts explained, films of pandas mating should be shown to ignorant, innocent pandas like An-An and Chi-Chi. (This use of video as a how-to tool is distinct from its use as a purportedly motivational device, as when one zoo tried to inspire its competent but uninterested male chimpanzee by showing him videotape of mating gorillas.)

  Nowadays many zoo pandas reproduce through feats of artificial insemination and the idea of showing them X-rated panda pictures is seldom mentioned, at least in the United States. There are still anecdotal accounts of pandas who learned what to do after viewing a video. But at many zoos, panda embryo transfer, rather than panda dating etiquette, is today’s exciting frontier.

  Was it a problem of who, or a problem of how?

  In the 1970s, in a famous gesture of rapprochement, China sent two pandas to the United States. Hsing-Hsing, the male, was delayed for several weeks in Beijing so he would have a chance to see other pandas mating. Yet, despite this learning opportunity, Hsing-Hsing developed what has euphemistically been called an “orientation problem,” making lustful approaches to Ling-Ling’s head or side. “It took him a few years to get it right,” says National Zoo behaviorist David Powell. When the pandas arrived, Powell says, “the instructions that came with them were to keep them separate. We thought that made sense, because they’re solitary animals.” But Powell now thinks one reason Hsing-Hsing had a hard time figuring out how to relate to Ling-Ling was that he was only around her for three days a year. Ultimately Hsing-Hsing got smart and the two pandas had five cubs through natural matings.

  Really, I’m flattered

  Sometimes malimprinting entirely changes an animal’s definition of acceptable family members and mates, and sometimes it merely expands the category. Unlike pandas, tigers are pretty good at figuring out that other tigers are the creatures they should seek when their fancy turns to thoughts of love. But they’re not infallible. Victoria, a Siberian tiger born in a zoo, was rejected by her mother and was given to Rosemary, a large dog, to raise. This is a regular practice when you need a foster mother for a great cat’s kittens, and Rosemary raised her striped child successfully. But when Victoria reached adulthood she refused to have anything to do with tigers, though she was offered four potential mates. Perhaps because she was an only kitten, she apparently imprinted on her foster mother’s species and found other tigers insufficiently doggy.

  Innumerable lions raised by Joy and George Adamson, as well as a cheetah and a leopard, were able to work things out with their wild opposite numbers, due to a flexible attitude. Rafiki, a lioness in an orphaned litter raised by Gareth Patterson, grew up to view him as her first choice for mate material. Although she was independent, whenever she was in heat she would drop by Patterson’s camp, ignore his girlfriend, moan loudly if he wasn’t there, and invite him to go on little excursions into the bushes if he was there. She escalated to more graphic hints as she got older. His persistent refusal to take her meaning drove her into the arms of an actual lion, and she produced a litter of cubs. Patterson writes that George Adamson, his mentor, confided that he sometimes had to climb a tree to get away from a sex-crazed lioness.

  Leopards raised and released by Arjan Singh in India found and mated with other leopards. It must be admitted that the leopard Harriet had a disturbingly open-minded attitude, and when she was in heat and the male she had been mating with was out of the area, she would turn confidingly to Singh, who was ultimately forced to sleep in a cage to “avoid [her] amorous advances…. Until then I had wardedher off, if I had to, with a stick, but lately she had begun to seek relief from her problems by climbing on to my bed, and this was too great a nuisance to be tolerated. Not only did I lose sleep; she also kept ripping my mosquito net in trying to get at me.”

  Even when romance is not an issue, there can be problems with hand-reared animals. People who raise llamas have learned that a hand-raised female llama is friendly and confiding and treats you as if you were another llama. But a hand-raised male llama also treats you as if you were another llama, and he would like you to acknowledge him as a superior llama. (For, admit it, wonderful and versatile though you may be, you are a poor excuse for a wool-bearing camelid.) Llamas can be very rough with each other, so being treated like one of the gang is a bad thing. Baby llamas are among the most adorable baby animals in existence, and it’s hard to keep in mind that such a big-eyed, long-lashed, fluffy thing might, if it accepts you fully, one day insist on beating you up and spitting on you to show you who’s boss.

  I can never be more than a rehabber to you, darling

  A released animal that is merely habituated to people may be lucky enough not to get into trouble and go on to lead a normal life, but wildlife rehabilitators know that an animal that is imprinted on people may seek them at mating time, wi
th unfortunate results. Owls, for example, readily imprint on people or, more specifically, on people’s heads. If you are strolling through the woods and an owl swoops out of nowhere and comes at your face, you are unlikely to think, “This poor fellow is enchanted with my head, and who can blame him? Probably he’d like to settle down and raise a family with my head. No wonder he’s following me, hooting crazily.” Owls who do this tend to get clubbed to death or shot. Wildlife rehabilitator Kay McKeever writes that people usually think such an owl is rabid (even though owls don’t get rabies).

  Even if the owl does not try such a direct approach and merely hangs around hooting lasciviously at the head of its dreams, and swooping by as a method of displaying its own charms, trouble can ensue when the owl feels compelled to chase away possible rivals. “This might be laughable in a Robin, or even in a disorientated Saw-Whet Owl, but it is not so funny when the bird is a Great Horned Owl, with the striking power in his legs and talons and the serious intent of his ancestral behavior,” writes McKeever. “Then it is truly dangerous.”

  To avoid such perilous imprinting, rehabilitators try to supply orphans with owl foster parents on whom they can imprint appropriately. Interestingly, McKeever writes that the ideal foster parent is a male owl of the same species who is himself imprinted on humans (so he won’t attack rehabbers and will allow them to move to and fro). Even though he is imprinted on humans he will still respond to owlets. “Providing the juvenile owls make food-begging calls, the male’s innate instinct to respond is a powerful drive, apparently overwhelming any visual incompatibility with the young.”

  If such a foster parent is unavailable, McKeever describes a method of putting the owlet in a nest box from which it can at least see an adult owl. Meanwhile the human caretaker feeds the owlet surreptitiously from the other side of the box, taking care not to be seen or heard.

  The rehabilitator will have succeeded if, after having spent weeks devotedly tending to an orphan, she approaches and is greeted with a defense display of an owl crouching, spreading its wings to look scary and large, and clicking its beak in the manner that denotes “Come any closer and I’ll shred your flesh!”

  In the early 1970s, falconer Robert Berry had two American goshawks he hoped to breed. But they were imprinted on humans and wanted no contact with each other, the female being particularly vehement about her dislike of goshawks. (She was kind to a goshawk chick and treated it as her child until it was a few months old, whereupon she decided that she hated it too.) For the good of the species, Berry acted as go-between. He was able to convince the male goshawk to focus on Berry’s leather glove as a love object. The male built a nest and courted the glove with clucking and bowing, finally (after unsatisfying liaisons with a paper bag and Berry’s shoe) mating with it more than a hundred times. Berry was able to collect semen in a syringe on 15 of these occasions. Then Berry’s glove romanced the female, during which Berry was able to artificially inseminate her using the syringe. It worked, and the female laid fertile eggs.

  Richard Zann writes fondly of the zebra finch Fred, whom Zann hand-raised from a nestling. Fred was imprinted on Zann or rather on his fingers and face. After running into problems in the aviary where the more bird-oriented finches lived, Fred was confined to a cage on top of a filing cabinet behind Zann’s desk. The finch could not see the beloved fingers and face unless Zann turned around, but Fred learned “by trial and error” that he could flick a drop of water from his automatic waterer onto the back of Zann’s neck, causing the graduate student to turn around, exposing his fingers and face to Fred’s adoring view, whereupon Fred would launch into his courtship song and dance.

  Who knows what goes on out there?

  While most other examples of cross-fostering that we know about are in domestic or captive animals, there must be others in the wild we never learn about. R. M. Lockley, who spent years living on an isolated British coastal island where seabirds nested, often saw puffins and shearwaters fighting over a burrow in which one had already laid an egg. In one case, Lockley had marked a shearwater’s egg (to see how long it took to hatch), which the shearwaters had already begun to brood. “The puffin, after several pitched battles, had taken over the shearwater’s egg, incubated it, but failed to hatch it,” Lockley wrote.

  In Alaska, wildlife filmmakers found a white-tailed ptarmigan with a mixed clutch of chicks, some white-tailed ptarmigans like her, some rock ptarmigans. They speculated that she crossed paths with a rock ptarmigan family, and that when the families went their separate ways the chicks got mixed up. In any case, she treated the little rock ptarmigans as her own.

  For four years in a row, the same long-finned pilot whale, probably an immature animal, was spotted swimming with white-sided dolphins off the coast of Massachusetts, with no other long-finned pilot whales in sight. The whale was never seen with other whales. The long, solitary companionship of the whale with the dolphins “raises questions regarding the possibility of cross-fostering and the implications of imprinting upon social development and reproduction,” observers wrote.

  And whose little kitten are you?

  An animal that has successfully figured out who its parents are, who its friends and enemies are, and who its potential mates are should surely have no problem figuring out who its children are. But as we have seen in cases of cross-fostering, animals can make mistakes or exhibit generously broad definitions. They can also be fooled.

  There are several groups of birds who do not raise their own children, but instead trick or force other birds into doing it for them, a practice known as nest parasitism. The Old World cuckoos are famous for this. The American brown-headed cowbird is so successful at this racket that it is said to threaten the survival of some other species.

  Female nest parasites lurk, noticing where other birds are building their nests. When the time is right, they dart in and lay an egg. Usually they do this when the nest is unguarded in the early days of egg laying, but in some cases, they squeeze in next to the outraged occupant of the nest and attempt to lay their outlander egg before they are booted off.

  So a female cuckoo may lay an egg in a reed warblers’ nest, among the reed warblers’ eggs, when the reed warblers have stepped out for a quick caterpillar. When the reed warblers return, they incubate the egg along with their own. The cuckoo’s egg hatches sooner than the reed warblers’ eggs. The baby cuckoo is bigger and squawks more loudly than the reed warbler chicks. Often the cuckoo chick pushes the other chicks out of the nest, one by one. The cuckoo grows quickly and often gets to be bigger than its foster parents, who valiantly feed their giant impostor darling. When this scam works, a cuckoo mother can get a lot of eggs raised by reed warblers and other birds, more than she could raise herself.

  Many birds—typically species that have evolved in the presence of nest parasites—will kick out the foreign egg, but others do not. Cuckoo eggs often look like the eggs of their unwilling hosts, spotted if the host’s eggs are spotted, brown if the host’s eggs are brown, and so forth. This raises two species-recognition questions, which apply to all nest parasites. The first question is why the reed warbler can’t tell the difference between its own eggs and chicks and cuckoo eggs and chicks. The second question is how the cuckoo, which is tenderly raised by reed warblers, knows to mate with another cuckoo, and not a reed warbler.

  A mother’s heart knows her own child

  As for why birds can’t recognize their own eggs, some birds can. Some species of birds abandon their nest if a cuckoo lays in it, or simply build a new nest on top of it. In the United States, studies suggest that species that have lived for a long time in the same area as cowbirds—nest parasites—are apt to be suspicious of strange eggs, and species that have not lived in the same area are apt to be too trusting.

  You’re no child of mine

  Some birds imprint on their own eggs or babies the first time around. One researcher who quickly substituted different, paler eggs each time a couple of first-time breeding garden warblers
laid an egg apparently succeeded in deluding them about what their own eggs looked like. When they laid their fourth egg among three substitutes, they viewed it as a phony and kicked it out of the nest themselves. The birds seemed to remember, after the first breeding season, what their eggs should look like, so only eggs that looked like theirs could pass muster.

  Bernd Heinrich performed egg-switching experiments with ravens to see how far he could push them before they’d realize “That is not my egg.” They would accept a chicken’s egg Heinrich had painted to look like a raven’s egg. They would accept a plain white chicken egg. They would, after some fussing, accept a chicken egg that had been painted red. However, they would not accept a black plastic film canister, even though it was the same weight as a raven’s egg. (Consider the Laysan albatrosses who were induced to lavish parental devotion on a big yellow grapefruit: they were excused as birds with “little breeding experience.”)

  On another occasion, Heinrich needed to find a home for four orphaned raven chicks. He had been following the nest of a pair he knew well, Goliath and Whitefeather, who had two younger chicks, and who were nesting in a shed near his house in the woods. In the middle of the night Heinrich removed their two chicks and put in the four older orphans. At sunrise, father and mother regarded the chicks calmly, despite the fact that they were bigger and had doubled in number. But when the sun shone directly into the shed, spotlighting the nest, both parents suddenly seemed shocked. “The adults stood as if dumbstruck, intently examining the young. Both moved their heads quizzically from side to side, looking at the young in their nest first with one eye, then with the other from a different angle.” Whitefeather, the mother, erected her head feathers, a sign of agitation and cried “kek-kek-kek” in alarm. This reminded the chicks to beg for food, and she pecked angrily in their direction, without touching them.