Many other wildlife rehabilitators have found that they must raise baby animals and tend injured adults in a hands-off way that does not reflect their concern for the animals, in order to keep them from becoming attached to or overly casual about humans. Thus Jeanne Lord, an expert on red fox rehabilitation, not only puts up screens so that she can stay out of view of the foxes she cares for, but avoids speaking, even in a whisper, where they can hear.
It has been suggested that tigers in Ranthambhore Park, who became tolerant of daily jeeps full of tourists, accordingly became easy targets for poachers.
Excessive familiarity with humans can play out in more than one way. In an experimental release of endangered Bali mynahs on the island of Pulau Menjangan, confiscated cage birds were used. Cage life had not filled them with love and trust for humans, but rather with contempt. The researchers complained of “antagonistic behavior to birdkeepers.” Even after release the mynah LR04 would fearlessly fly down and peck observers on the ear. The scornful LR06 several times landed on an observer’s head or attacked his boot. While both these birds succumbed eventually to a falcon, another was stolen by a poacher, perhaps in mid-sneer.
Chimpanzees released in Rubondo Island National Park in Tanzania, who came from German and Dutch zoos, also did not admire people. Of course, the reason the zoos were willing to yield up these particular chimps often had to do with their surly outlook. Most of the apes faded into the forest, but two of the males attacked people so fiercely that they were shot. The chimps were released in the late 1960s, but a few of the original zoo chimps were probably still around in the late 1990s, when one chimp was spotted stealing a blanket to wrap herself in and another was noted entering a store at the tourist camp and subsequently swigging from a bottle of liquor.
A lone bottlenose dolphin appeared in the coastal waters north of São Paulo and began socializing with humans. He followed ferries and small boats for a few months, and that was nice. Then he moved to the beach at Caraguatatuba and started mingling with bathers. People are a mixed bag. Bathers made contacts that included “simple touches…riding and jumping on his back, grabbing his fins, hitting him and even putting an ice-cream’s stick into his blowhole.” The dolphin began to respond sharply, sending 29 people to the hospital with injuries. Finally, he objected to a couple of drunken bathers, hitting them so hard that one went to the hospital with two broken ribs and the other died of internal bleeding, a first in dolphin-human relations. (The beach was patrolled for the rest of the season, and no one else was hurt.)
Sometimes not being afraid of humans is an advantage. Biologists reintroducing beavers to tributary streams of the Vistula River had both farm-raised and wild-trapped beavers at their disposal, and chose to release the farm-raised beavers in those sites “often troubled by man.” The farm-raised beavers weren’t scared off the way the wild beavers were.
In Monkey Mia, a cove in Shark Bay, in western Australia, some dolphins come into the shallow water and interact with people, who feed them fish. Most of the Shark Bay dolphins don’t do this, and it’s something dolphins learn. They learn where to come, and they learn the protocol. Biologist Rachel Smolker writes that there is a specific begging posture, in which the dolphins brace their pectoral fins against the sandy bottom, and hold their head up out of the water with open mouth.
Smolker describes a dolphin called Joysfriend, who didn’t usually come into the shallows. One day she visited, accompanying some dolphin regulars. “She stopped and looked around expectantly, as if to say, ‘Okay, so where’s the fish?’ She moved back offshore and seemed to watch the other dolphins approach people and take fish. A while later she tried again, this time bringing her face up out of the water but failing to open her jaws. She was going through some of the motions, but again, she was several yards from the nearest person and still didn’t have her jaw open. She looked awkward, like a person taking his or her first stab at stage acting.”
What to do?
Creatures of other species who will feed you are few and far between. Meeting an enemy is more likely, and it’s important to know how to act in such a case. How to act if you spot an enemy is such vital information that few animals that had to pause and learn the skills are still around. How to run, or freeze, or dive, or whatever it is that your species does, is generally built in. Practice can help, though.
When scientists kept baby guppies in a tank with adults, the adults chased the little guppies up to 300 times a day. Two days of this discipline was enough to give the young guppies an edge when they were put in another tank with bloodthirsty cichlid fish. Guppies who had not had to spend all their time dodging grouchy grown-ups were not nearly as good at getting away from cichlids.
Three-spined stickleback fathers guard their eggs, and when the tiny fish fry hatch out, the fathers guard them for another week and a half. When the little fish swim too far from the nest, the father chases them, catches them in his mouth, takes them to the nest, and spits them back into it. J. J. Tulley and F. A. Huntingford collected stickleback eggs and hatched them in the laboratory. The eggs were collected from Inverleith Pond, which is practically a stickleback sanctuary, with no fish-eating fish; or from the Burn of Mar, where fish-eating fish and birds abound. Half the eggs from each location had a father’s tender care after hatching, and half grew up as orphans. When they were big enough, they were placed, one at a time, in an aquarium with “a realistic fibreglass model pike.” After two minutes, the experimenters moved the realistic pike around “to mimic the stalking of a live pike” and scored the responses of the young sticklebacks. The young fish got points for retreating from the model and keeping their distance and lost points for feeding in open water without looking at the model predator.
Fish who had normal upbringings and whose parents came from the dangerous Burn of Mar were warier than fish from peaceful Inverleith Pond, showing a hereditary effect. But the Mar Burn fish were warier if they had a normal upbringing than if they had been orphans, suggesting that learning to dodge their father was useful practice for dodging pike.
You’re not fooling anybody
If you are an edible individual, and you notice a predator sneaking around, it may be useful to let the predator know it’s been spotted and doesn’t have a chance of taking you by surprise. Many antelope stot or pronk: they run with short, high bounds, often flaring out white hair on their haunches. Although stotting makes antelopes conspicuous, it tells predators they have been seen, and seen by a creature that has the energy to stot. No point wearing yourself out chasing that one. Similarly, hares may stand on two legs, with their body and ears sticking up. Again the message is clear: I see you, creep.
Oh no! Any second now you’ll grab me!
Grouse and ptarmigan are among ground-dwelling birds who perform distraction displays when they and their chicks are approached by a predator. The chicks scatter and sink down in the grass, where their streaked and speckled feathers are beautiful camouflage, and the adults flap up noisily and then stagger away as if crippled and mentally impaired, often dragging one wing as if injured.* Meanwhile the chicks are motionless and invisible. Often the predator will follow the adult, who flops just ahead until they are far from the chicks, whereupon the adult miraculously recovers, and flies off. Thus a naturalist doing a census of blue grouse on Vancouver Island was beguiled by the sight of a grouse hen acting like a maniac, clucking and staggering just out of reach of a black bear which ran after her until she had led it out of the valley where it had been nosing about.
A tame duck sitting on her nest spotted an otter (also tame) coming toward her with mischievous intent and, although she had no experience of otters and had never seen a distraction display performed, immediately stumbled off her nest and staggered through the water, flapping and quacking. The thrilled otter pursued her to the end of the pond, where the duck suddenly leapt into the air and flew off. “The otter’s air of bewilderment was laughable,” wrote Frances Pitt. Nor did it occur to the naive otter to go back a
nd look for eggs.
Predators aren’t always fooled. One summer day, Geir Sonerud saw a fox hunting in a Norwegian forest. When a black grouse started up and began doing its oh-no-I-can-barely-walk act, the fox ignored the grouse and instead began quartering the area, nose to the ground, keeping it up for 36 minutes and apparently locating and snapping up two chicks. After strolling on, the fox flushed a capercaillie (a large grouse). The fox spent 32 minutes again quartering the ground for chicks, catching two, and ignoring the capercaillie hen’s desperate distraction displays.
Grouse do not perform distraction displays every time a predator approaches. Because grouse hens vary in the frequency with which they perform such displays for the benefit of hunters with dogs, and because the variation correlates with the number of inexperienced (and therefore perhaps easier to fool) foxes in the population, Sonerud speculates that foxes learn to ignore the hen and look for the chicks, and that grouse learn how likely they are to be able to fool foxes and therefore whether it’s worth putting on their act.
Researchers banding ptarmigan chicks in Sweden made use of dogs who didn’t get distracted. A knowledgeable person who sees a ptarmigan go into a display knows where to look for chicks but won’t be as good at finding them as a dog. V. Marcström has described the difficulty of getting the right dog. It should have a good nose and lack culinary aspirations toward the chicks. It must also learn to ignore the histrionics of the mother or father ptarmigan, with their pathetic staggering and dragging wings, and focus on the search for chicks, keeping its nose to the ground and methodically sniffing the ground bit by bit—in other words, to be clever as a fox.
Cognitive ethologist Carolyn Ristau studied the distraction displays of piping plovers and Wilson plovers, birds that fake broken wings if predators get near their nests. The nests are on sandy ground and are mostly protected by the perfect camouflage of the eggs. A faking bird fans its tail and stumbles across the ground, peeping, fluttering, and dragging one or both wings. Ristau calls this a mixture of genetic elements and “more flexible behaviors.” She investigated when plovers go into their act and how they employ it. The birds typically move closer to an intruder and start their displays in front of them. They don’t randomly head in any direction—they head away from the nest. As they skitter away, they often look over their shoulders, enabling them to see what the intruder is doing. If the intruder doesn’t follow, they often stop displaying and go back toward the intruder and start again. Ahem! I’m crippled here! Take a look!
Ristau ran experiments with beach-nesting plovers, having distinctively dressed persons either behave innocently, walking past without glancing at the ground, or wickedly snooping around as if hunting for nests. The next time they came by in the distinctive outfits, the plovers were apt to do a distraction display for the egg-hunting types but sit tight for the innocent-seeming beachgoers. Thus a plover is born with the impulse to fake a broken-wing display if its nest is threatened, but it is also able to assess how the display should be used and learn whether it’s working.
Be careful, it might be some kind of a trap
One common method used by researchers studying wild animals is trap and release. Researchers record data on the trapped animals and let them go again. Kit foxes often become “trap-happy,” gladly entering traps for the sake of the bait. Other kit foxes become trap-shy, and these two phenomena are maddening to statisticians trying to create equations that translate trapping records into population estimates. Before the phenomenon of trap happiness became well known, one study of kit foxes noted that one individual was trapped every night. The puzzled authors concluded that the fox must be a moron (not an actual quote). But a fox fancier who had actually lived with foxes felt sure that the animal in question had simply learned about a safe den for the night that offered free continental breakfast.
David Macdonald, author of Running with the Fox, did not find it easy to trap red foxes. His first traps, which he calls “monuments to my naïveté,” didn’t catch a single fox in three months. They didn’t go unnoticed. Macdonald reports that the local foxes found his traps fascinating. “They circled them, urinated on them, dug under and climbed on top of them, defecated into them, even pawed through the mesh to extract the bait from within. The one thing that they never did was to enter.”
Eventually, Macdonald writes, he figured out that the traps were “too small, badly designed, poorly sited and incorrectly baited” and with improved technique began catching foxes and putting radio collars on them. He captured foxes repeatedly, and he writes of the vixen Toothypeg that after a while she knew the routine, stopped biting, and waited placidly while he replaced her collar.
One rainy dawn when Macdonald checked his traps he found an uncollared vixen with unusual markings. She stared at him strangely as he put a collar on her. When he let her go, she jumped up, snatched the cap off his head, and raced off with it, discarding it in a nearby field. Pondering her strange actions and odd markings, Macdonald suddenly realized that the vixen was a fox named Sickly that he and his wife had raised from a cub and released. (Her old collar had fallen off.) That night his wife gave the old signal for Sickly: rattling a can of chocolate candy. Sure enough, Sickly arrived in a brand-new radio collar. He hadn’t recognized her. Perhaps stealing his cap was a familiarity designed to remind him of their relationship.
In a patch of rain forest in Queensland, Australia, biologist William Laurance was trapping and releasing local small mammals. One day he set out some Elliot box traps, baited with oats. Elliot traps are designed to open out flat so they can be folded up when not in use. To do this requires pulling out a long wire that keeps the trap in the box position, a task Laurance needed pliers to perform. When Laurance returned one day, the bait was gone and all the traps had been opened, with the wires laid out neatly beside them. At first the baffled Laurance figured that local jokers, perhaps hostile to his research, had disassembled his traps, but it happened again and again. He had to rule out humans since he didn’t see any cars they could have come in, didn’t think they would keep getting up in the middle of the night to disassemble his traps, and was sure none of them would take the trouble to lick the traps clean.
To find out what was going on, he interspersed the Elliot traps with cage traps. On his return the Elliot traps had been unfolded and cleaned out as before, and the cage traps held bush rats, fawn-footed melomys rats, and giant white-tailed rats. Laurance accordingly dusted each rat with nontoxic Day-Glo powder by species: the bush rats were blue, fawn-footed melomys were green, and giant white-tailed rats were red.
The next day the Elliot traps were opened, unfolded, and every speck of bait had been eaten, and they were speckled with red powder. The safecracker was a giant white-tailed rat—or rats, since, sadly, Laurance did not take the next step to determine whether there was a single rat at work or whether all the local giant white-tailed rats knew the trick.
Watch this!
The cunning of keas and their willingness to experiment made trapping them (for banding) a task that tested the ingenuity of all concerned. The researchers used drop nets baited with butter. Keas adore butter but they dislike being netted, so they tried to outwit the humans. One kea would go over to the net, which was poised to fall, grab the side, and shake it until it fell. Then the kea would clamber on top and eat butter through the mesh. Other keas waited until someone else had sprung the trap and then dashed out to snag the butter. Some specialized in what the researchers called the “fast run-through,” in which they dashed under the net, snatched the butter, and tried to race out the other side before the startled biologists could drop the net. In order to keep the keas guessing, they had to keep moving the net and switching to different-colored nets. Thus scientific efforts to learn about animals are thwarted by animal learning.
Learning to avoid danger is one of the most clearly useful forms of learning. Innate reactions to some perils—huge birds with big talons—are valuable to some animals. But new menaces come along, and
animals who can learn have the best chance of escaping them.
SEVEN
Invention, Innovation, and Tools: How to Do Something New, Possibly with a Stick
A hand-raised blue jay in a psychology laboratory, irked because some of the food pellets it was fed fell outside the cage and lay out of reach, devised a technique for dealing with this. The jay reached through the bottom of the cage, tore off bits of the newspaper lining, and industriously crumpled the paper. Then it stuck the paper through the wires at the front of the cage, where the pellets lay, and manipulated the paper until pellets came within reach. This was not what the researchers had planned to study, but they couldn’t help being impressed. To see if the blue jay was set on using paper for this purpose, the fascinated psychologists offered the bird a feather, a paper clip, a plastic bag tie, and other items, and the jay used them all to rake in more pellets. Would the jay still try to rake in pellets if there were none to rake in? No, it would not. Would it try harder if it was hungrier? Why, yes.
When the researchers deprived the bird of pellets, the jay would sometimes dampen a piece of paper in its water dish and swab it in the food dish. Then it would either pick crumbs of food dust off the paper or simply eat the paper, dust and all.
The psychologists tested their eight other jays and found that five were tool users, two “displayed some components of the behavior,” and one didn’t seem to be a tool user at all, although it did like to play with paper. The researchers wrote that they suspected that one jay came up with the tool use thing “serendipitously,” was encouraged when it accidentally retrieved a pellet, perfected the system through trial and error, and then the rest picked it up through imitation or observational learning.
Becoming a Tiger: The Education of an Animal Child Page 25