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

  Becoming a Tiger

  How Baby Animals Learn to Live in the Wild

  Susan McCarthy

  For Mary Susan Kuhn

  With love, gratitude, and respect

  Contents

  Introduction: Why Learning?

  One

  How to Do or Know Something New: Ways of Learning

  Two

  Learning the Basics: How to Crawl, Walk, Climb, Swim, and Fly

  Three

  Learning Your Species

  Four

  How to Get Your Point Across: Being Vocal, Being Verbal, and Otherwise Communicating

  Five

  How to Make a Living

  Six

  How Not to Be Eaten

  Seven

  Invention, Innovation, and Tools: How to Do Something New, Possibly with a Stick

  Eight

  How to Get Cultured

  Nine

  Parenting and Teaching: How to Pass It On

  Ten

  What Learning Tells Us About Intelligence

  Conclusion: Secrets of a Tiger’s Success

  Notes

  Bibliography

  Acknowledgments

  Searchable Terms

  About the Author

  Praise

  Other Books by Susan McCarthy

  Copyright

  About the Publisher

  Introduction:

  Why Learning?

  SOMEHOW A FUZZY, STUMBLING tiger kitten becomes a monstrously efficient killer. Somehow a big-footed fool of a raven fledgling becomes an aerial acrobat and a masterful survivor in the north woods. Somehow a wide-eyed spindle-limbed squirrel monkey infant becomes a wily adult who eats a wholesome caterpillar and avoids a poisonous one. Somehow a panda finds love, a spear-nosed bat joins a sorority, and a bear who successfully holds a territory passes her hard-won gains on to her ignorant cubs.

  How do baby animals become competent adults? While part of the answer is that cubs and kittens and chicks mature and come into their powers, another part is that they learn what they can do and how to do it.

  Learning is the ultimate combination of nature and nurture, in which a growing animal applies its powers of intelligence, curiosity, perception, and memory to the world around it, again and again, and ends up with knowledge and skills it did not have before. No newborn animal is a blank slate and no newborn animal has a complete instruction manual.

  Learning and intelligence are connected, but are not the same thing. We often ask questions like “How intelligent is a chimpanzee?” “How smart are pigs?” or “How dumb is my sister’s cat?” This book looks instead at what a chimpanzee, a pig, or a cat can learn. This kind of inquiry acknowledges change, examines the interplay between nature and nurture, and lends itself to narrative. In the end, it is a sneaky way of starting to answer the questions above.

  Learning has an odd status in our esteem. We’re impressed with people who know a thing without learning, who grasp it instantly. It’s not unknown for animal behaviorists to dismiss an impressive performance by an animal as “only learned behavior”—as opposed to intelligent insight. Yet nothing seems dumber than being unable to learn.

  (If you do much reading about learning and intelligence in animals, you will come across references to “Einsteins among the herons,” “a raven Einstein,” “an Einstein among macaques,” or “an Einstein of a Herring Gull.” I hope not to succumb to such temptation.)

  Learning is a process, not the static image provided by an intelligence test. It’s an intrinsically hopeful process of improvement. As an animal, I am also perpetually beguiled by the bumbling folly of baby animals, while also understanding that what I see is not stupidity, but an early stage of a journey toward grace, competence, and comprehension.

  As an optimist I am all in favor of learning as much as possible. I am idealistic enough to think we’re better off learning how sausage is made, though I admit there are times when I regret having learned that demonic form of solitaire my father plays.*

  This is not a book about what the study of young animals can teach us about child-rearing. But since we are animals ourselves, a certain amount of illumination is unavoidable.

  IN RESEARCHING WHEN ELEPHANTS WEEP, my coauthor Jeffrey Moussaieff Masson and I had to wrestle with a widespread scientific reluctance to write of emotion. Researching this book didn’t present that problem. That animals feel emotion is still anathema in some circles; that animals learn is not. How animals learn is often the controversial part. Do animals imitate each other? (Is that true imitation?) Do they pass on learning in the form of culture? (Is that really culture?) Do they teach their children? (What counts as teaching?) I sifted the research for animal stories that illustrate different kinds of learning.

  Many stories in this book come from scientific journals and books, but some come from wildlife rehabilitators. In wildlife rehabilitation there are many cases of baby animals and birds who didn’t have natural childhoods in the wild. As a result, what sometimes seems like the effortless and neatly programmed progress of an animal from birth to life as a grown animal is discovered not to be inevitable. Seams show. Strange gaps appear. Unnatural liaisons are suggested. Wildlife rehabilitation is an occupation that seeks, among other things, to discover what an animal needs to be exposed to and to learn in order to have a normal life.

  The reintroduction of endangered species, under the supervision of scientists, draws on the skills of wildlife rehabilitation. The pitfalls in reintroducing black-footed ferrets are not the same as the pitfalls in reintroducing whooping cranes, but all throw light on the nature of these animals. To save the species it may be vital to teach ferret kits not to spend so much time on the surface of the prairie dog colony; to ensure that crane chicks don’t get wrong ideas about romance and family; or perhaps, someday, to provide mentors for tiger cubs.

  The ability to learn is an adaptation of tremendous power, one which has taken our own species a long way. We even go to the extreme of learning about learning, as in this book.

  ONE

  How to Do or Know Something New: Ways of Learning

  Studying killer whales off the Canadian Pacific coast, researcher Alexandra Morton spotted an eaglet learning that not all birds are alike. The nest he had hatched in was in a fir tree by the shore. Gazing keenly about, the eaglet saw a great blue heron standing on floating kelp. Deciding to do likewise, the eaglet flew down to alight on the kelp. Instead of standing on it with splayed toes as the heron did, he gripped it like a bough. The seaweed sank when the young bird landed on it, and he plunged in. He struggled free, but didn’t give up the project. “Again and again the eagle alighted and sank to his breast, flapping wildly to avoid drowning,” writes Morton. It took all morning before the eaglet abandoned hope of becoming the Terror of the Kelp.

  AN EXPERIMENTAL PROCESS of trial and error persuaded the young bald eagle that at least one perching place wasn’t for him. Some baby animals are born with most of the skills they will use in their lives, and need to gather very little information to make their way through life. Others must learn many skills and collect a great deal of information if they are to survive.

  There are many ways to learn. An orphaned fox cub at a rehabilitation center who stops panicking every time someone puts a food pan in its cage is becoming habituated. An owlet flapping its wings and trying to fly to a higher branch is practicing. Wrestling puppies come to understand social relationships by playing. A tiger cub with newly opened eyes is learning to see by forming neural connections. A day-old chick that begins foraging by pecking indiscriminately at seeds, bugs, and its own toes (and switc
hes to pecking only at seeds and bugs) is using trial and error. When a young raven, cawing fiercely, joins with the rest of the flock in mobbing a creature it has never seen before, the fledgling is undergoing social conditioning. These are all forms of learning.

  Researchers have carefully examined many of the ways animals learn, and have focused a lot of attention on which ways to learn are available to all kinds of animals and which are special to only a few top-flight species, particularly the human species. But that animals of every kind learn in at least some ways is undisputed.

  Why learn?

  A young rabbit being closely pursued by a predator zigzags crazily from side to side. The rabbit covers less ground this way, but because it’s nimbler than a big wolf or bobcat or eagle, it stands a chance of getting away by dodging. This is an excellent strategy that might not occur to me if a monster were suddenly hot on my heels. The young rabbit doesn’t have to learn zigzagging—a rabbit’s life is short, and if it had to learn its evasive tactics would be even shorter. This is great, unless the rabbit stupidly jumps out in front of your car, realizes that it’s in trouble, and starts zigzagging down the road in front of the car. If rabbits lived a long time, and were protected from predators by their parents while they slowly learned about the world, we might hope they would come up with a better way not to be hit by cars. (How about not jumping in front of them in the first place, pal?) Not having time, rabbits are born ready to zigzag.

  Being prepared ahead of time or thinking on your feet?

  Why go to the trouble of learning if you can just be born knowing how to dodge? You may dodge when it’s inappropriate, like the rabbit in front of the car. You may be unable to learn new strategies, like crossing the road after the car comes, not before. Species vary tremendously in how much of their behavioral repertoire is learned. The zoologist Ernst Mayr proposed the metaphor of closed and open programs. Mayr defines a closed program as one which does not allow appreciable modifications, and an open program as one “which allows for additional input during the lifespan of its owner.”*

  An animal with a closed program recognizes mates without having to learn what their species looks like, usually by one or two key features or a ritualized display. An animal with an open program learns what prospective mates should look like, often by observing its own family. A frog doesn’t need to learn what a suitable frog mate looks like, but an owl must learn to spot a suitable partner. Many animals have closed programs for some aspects of their behavior and open for other aspects.

  I once raised two small Virginia opossums whose mother had been hit by a car, and they operated largely on closed programs. Things they simply knew included how to hiss (showing 50 teeth), how to curl up in a ball, how to hang by their tails, how to beat up a cat that jumped them, and how to catch fledgling birds. They knew that fledgling birds and rotten apples were good to eat (they thought almost everything was good to eat). They knew they should waddle along, sniffing, until they smelled food. They knew that climbing upward was a good way to be safe.

  They were open to some new information. They learned that I was a friend who would protect them, and so when I took them to the woods, thinking they’d like to explore, they whirled in alarm and clambered up my legs—because they hadn’t learned to know the woods. They learned that I wouldn’t really let them fall if they refused to hang by their tails.† They learned that my dog and my cat wouldn’t bother them. And that was about all.

  Species with short lifespans, like opossums, have little time to learn, so they are apt to have more closed than programs open. Animals whose parents take care of them for a long time have a chance to learn while protected, so they are apt to be able to afford more open programs.

  Whenever there’s usually one right thing to do in a clearly recognizable situation, a closed program is perfect. If there’s something in your eye, you should blink, not ponder. If a cat attacks you, show all 50 teeth right away.

  But if the choices you face are more complicated, and the world you live in keeps changing, open programs might be more successful. “The great selective advantage of a capacity for learning is…that it permits storing far more experiences, far more detailed information about the environment, than can be transmitted in the DNA of the fertilized zygote,” writes Mayr. “If it is to survive in a constantly changing environment, a bird cannot rely exclusively on the genome. There are far too many gaps in this network of inborn information,” writes Jürgen Nicolai, a scholar of birdsong.

  Then there’s the thrift issue. Getting information by learning (as opposed to having it stored in the genes) saves space in the genome. Of course, then you need more space in the brain, and brains are expensive to run, metabolically speaking.

  The nature of nurture, and nurturing nature

  Closed programs and open programs refer to nature and nurture, two sources of behavior that are pitted against each other in many arguments about why humans do what they do. Are we born the way we are, or do our environment and upbringing make us the way we are? Are there fewer women in politics because women are less competitive or because cultures derail their ambitions? Are criminals bad to the bone, or were they simply raised wrong? Do nations make war because our species can’t resist, or is it just that we made the mistake of getting into agriculture?

  Scientists regularly become discontented with terms like “instinct” and “innate” because they are so imprecise. But try not to use them, or come up with synonyms, and the concepts keep coming back. It’s too hard to do without them. Many books on behavior, especially human behavior, begin with an obligatory passage about how both nature and nurture are important—but then often go on to stress only one of the two. The struggle is probably inescapable. If we could prove that some aspect of human behavior, for example, is 50 percent innate and 50 percent learned, battles would erupt about whether it isn’t 51 percent and 49 percent or the other way around. Since the subject here is learning, the nurture/slate-with-a-little-room-left-to-write-on/open program camp will be well represented, but it’s really true, just as the obligatory disclaimers say, that nature and nurture are incredibly entwined.* So there’ll be lots of examples of closed programs, although they may get embroidered by an animal’s experience and intelligence.

  An innate behavior is often modified by learning. No one had to teach you to sneeze, but one hopes that someone taught you to grab for a handkerchief or tissue when sneezing. Even the most elaborate innate behaviors are assembled in a series of environments. Genes are transcribed and proteins are assembled in environments within the cell, embryos develop in environments within their mothers, and behavioral triggers are encountered in environments.

  Imprinting, which will be discussed in scandalous detail later, is a classic example. The infant animal or bird has, in the middle of its closed program for many behaviors, a big blank spot that says only Your Parents’ Names Here. The closed program of the gosling says to follow its mother, peeping, but who mother is must be learned.

  Primatologist Hans Kummer has compared attempts to determine how much of a trait is genetic and how much is produced by the environment to an attempt to decide whether the sound of drumming is made by the drummer or the drum. But, as Frans de Waal puts it, if the sound changes, “we can legitimately ask whether the difference is due to another drummer or another drum.”

  I’m so mixed up

  An interplay of instinct and learning can be seen in hybrid lovebirds. Lovebirds, who really are the cuddly and constant little parrots their name implies, come in different species with different habits. When building a nest, peach-faced lovebirds cut long strips from bark or leaves, and then tuck the ends of the strips under the feathers of their lower back and fly to the nest site. About half the strips fall out along the way, of course, but they get the job done.

  Researchers crossbred peach-faced lovebirds with Fischer’s lovebirds, who do the rational thing and carry strips of nesting material in their bills like most other birds. The young hybrids, nesting
for the first time, “acted as though they were completely confused.” They cut lovely strips, and they seemed to have some vague but powerful idea that they should tuck something in their plumage, but they could almost never manage it. They occasionally seemed to feel that carrying strips in their bills might also be good, but first they needed to do some tucking. All the tucked strips fell out. After two months of this, the young hybrids carried about 40 percent of strips in their bills, but they still spent lots of time making tucking gestures before flying. It took them three years to more or less give up on the tucking thing.

  Conditioning

  For a large stretch of the twentieth century, the only kind of learning many animal behaviorists were willing to talk about was conditioning. Conditioning comes in two kinds, Pavlovian and operant conditioning, which do not always get kept neatly separate in life. Pavlovian conditioning is also called classical conditioning (because it got talked about first) or associative learning. It has been referred to as a correlation-learning device. Pavlov’s dogs famously came to salivate when they heard a bell, because when the bell rang, they got fed. Drooling when they got fed wasn’t learned, but associating the bell with food—and drooling—was.

  Fish whistle

  In the 1930s, when it was generally thought that fish could not hear, Karl von Frisch began whistling to a blind catfish in his laboratory before he put food in the tank. After a few days, when the fish heard whistling, it would come out of the drainpipe where it lurked and search for food. The proof that at least one fish could hear led to many other experiments on fish hearing.