We all start out in life as tiny babies with some instincts but a whole lot more to learn. It's the same with animals. How do the tiny babies of the animal kingdom learn what they need to know to survive in the wild? Writer Susan McCarthy explains the process in her new book, Becoming a Tiger. She explains why some skills are innate while others have to be learned.
"A behavior is often instinctive if it's something that you absolutely must have," explains Susan McCarthy. A rabbit instinctively knows how to zigzag when a predator is chasing it. And so if it's being chased by a wolf or a bobcat or an eagle, the rabbit will zigzag from side-to-side to get away, and this is a good strategy because the rabbit is nimbler, so it has a good chance of getting away. The rabbit is born knowing how to do that because it wouldn't have very many chances to learn."
That zigzagging may be instinctive, but Ms. McCarthy says young rabbits do learn other things, such as how to recognize the alarm calls of other species by watching its parents react to those calls.
Another thing animals learn from their parents is what to eat and what not to eat.
"A lot of animals will go up to other animals - their parents or other animals in their troop - and sniff their breath," she said. "The baby animals will come and sniff their breath to see what their parents are eating. People who have raised orphaned bear cubs have discovered that if they take the orphaned bear cub up to something that they think the bear cub should be eating and they don't eat it themselves, the bear cubs won't eat it."
Scientists can often learn about animal behavior by observing animals in the wild. But much can be learned from animals in captivity, too. The process of how animals learn to survive in their natural habitat is of keen interest to wildlife rehabilitators, who prepare animals for release into the wild. But Ms. McCarthy says rehabilitators face certain challenges.
"Well, a lot of times you want to teach the animal to do something that you can't or won't do yourself. So it's hard to teach a bird to fly," she says. "Now, birds instinctively do know the wing motions to flying, but they don't know that they can't land on a little skinny branch if they're a big bird. And you can't teach them that."
Another problem rehabilitators face is imprinting, an early-learning process in animals that can lead to a kind of identity crisis.
"Usually a baby animal learns what kind of animal it is by looking at its own family, and if its own family is human beings, and you then release it into the wild, that can create problems," she says. "In the whooping crane rehabilitation effort, scientists have gone to great lengths to prevent whooping cranes from imprinting on human beings. And so the people who work with the baby whooping cranes, they dress in crane suits, they carry crane noisemaker so that they can make crane noises. And as you can imagine, a grownup human being can't really disguise themself as a crane. But they're the right color, and at least they don't look like human beings."
That a bird could mistake a human being for a member of its own flock seems surprising. You would think it would be instinctive. But when I asked Susan McCarthy about it, she reminded me that animals change over time.
"If you had, in your heart, in your brain, if you had a picture of what your parents should look like, then when you evolve to be a different kind of bird or a different kind of animal, that image would have to change in lockstep, which is a much harder thing for natural selection to manage," she says. "So if natural selection has you programmed to look around and say, whoever I see who's being nice to me, that must be my parents - that works much better from an evolutionary point of view, that's something that natural selection gives the nod to, so to speak, even if the species changes."
One related identity problem facing animals that are raised in large groups is how baby and parent recognize each other.
"Sometimes this is incredibly difficult," she says. "Bats, for example, live in these colonies of thousands and thousands of bats. And the scientists who studied them used to think, It would be impossible for any mother bat to find her baby bat in that crowd. But they did experiments and found out that's not true, she looks for her own baby and the baby calls for its own mother. They do it on the sound of the voice, and when they get close, they smell each other."
Learning, says Susan McCarthy, connects heredity and environment. As a young animal grows to maturity, it combines its innate knowledge and intelligence with skills learned from parents and other adults to survive and thrive in the wild.
Ms. McCarthy's book, Becoming a Tiger, is published by HarperCollins.