As animal parents struggle to help their young survive their first days in the wild, they face seemingly insurmountable odds.  Penguins travel literally the ends of the Earth to protect their infants, facing Antarctic blizzards while they incubate their eggs. Amaurobius spider mothers offer their own bodies for their newborns to feast on. Orangutan mothers face up to eight years of single parenthood raising their infants.

Understandably, the process of birthing and raising young is one of the most stressful experiences an animal can endure. And it is in these very trials that the most extraordinary glimpses of life in the wild come to light. This film premiered November 1, 2009.

Photo © Philippe Clement

For decades after people first tried to keep gorillas in captivity, any gorilla’s path from the forest to the zoo was soaked in blood. As NATURE’s Snowflake: The White Gorilla shows, the animals had to be captured in the wild when they were young — before they grew too big and powerful to handle. Hunters would first have to kill the baby’s parents and sometimes its entire family.

This gruesome situation began to change in 1956 when a zoo in Columbus, Ohio became home to the first gorilla ever born and raised in captivity. Her name is Colo, and “she almost didn’t make it,” says Jeffrey Lyttle, author of Gorillas In Our Midst, a book about the Columbus Zoo gorillas.

“At the time, the zookeepers knew that Colo’s [mother] was pregnant, but nobody knew the gestation period of a gorilla,” Lyttle recalls. “They thought it was nine months, like humans, but it turns out it is closer to eight and a half months. So they weren’t expecting the birth. A vet named Warren Thomas was making his morning rounds when he discovered Colo, in her amniotic sack, lying on the concrete floor of her mother’s cage. He reached in, tore open the sack, and began giving Colo mouth-to-mouth resuscitation.”

Luckily, the little gorilla lived. “It was huge national news,” says Lyttle. But zookeepers believed that Colo’s mother wasn’t up to the task of raising her baby. They were probably right, since many captive gorillas never had a chance to learn parenting skills from their own parents in the wild. “So Columbus built a special nursery for her,” Lyttle explains. “Zoo visitation went through the roof. They would dress Colo up for the holidays — put her in an Easter bonnet and fancy dresses. Some people say she still likes to wear her food dish as a hat because she spent so much of her infancy wearing hats.”

A dozen years later, Colo gave birth to her first offspring, and she has since had several more; in NATURE’s Snowflake, viewers get to meet Dotty, Colo’s great-granddaughter.

Much has changed in the years between Colo’s and Dotty’s births. More and more, captive gorilla babies are being raised by their own mothers as zookeepers learn how to re-create more natural conditions. In cases where the mother still may not be able to handle the job, they have developed sophisticated surrogate parenting programs, where the babies spend a short time with human caregivers and then are quickly given to other gorillas to raise.

In Snowflake, Dotty meets her surrogate parents for the first time. It’s a tense moment — some surrogate parents won’t accept and care for their new offspring. Luckily, Dotty was accepted and is doing fine.

“Surrogacy has been extremely successful,” says Lyttle. “It was risky at first. These are very valuable animals, and there were these ideas that introducing an infant into a troop [a clan-like group of gorillas] could provoke violence. But the keepers believed surrogacy would work, and it has. It really shows how much our ignorance about gorilla social life has changed.”

Indeed, surrogacy has helped end much of the trade in wild gorillas. Today, about half of all gorillas that live in captivity are like Dotty — born and raised in a zoo, not torn from their families in the wild.

Rural children have who raised ducks or geese have long known about “imprinting” — or socially bonding to a parent figure. They learned that if they were the first moving object seen by newborn chicks, the young birds would soon follow them around devotedly. Many a delighted young farmer has paraded around the garden followed by “their” waddling brood.

But it wasn’t until the 1930s that a young Austrian scientist named Konrad Zacharias Lorenz formally documented the imprinting process — and gave it its name. Lorenz, who died in 1989 at the age of 86, ultimately won a Nobel Prize for his work.

Lorenz became interested in birds and bird behavior as a child. At one point, he recalled in an autobiography, “I yearned to become a wild goose and, on realizing that this was impossible, I desperately wanted to have one and, when this also proved impossible, I settled for having domestic ducks.” Soon, a neighbor gave him a one-day old duckling, which immediately began to follow Lorenz around, “to my intense joy.”

In college, Lorenz studied medicine and anatomy, but continued to keep and study birds and other animals. Then, in 1935, he published one of his most famous studies. In it, he showed that young ducks and geese could be “imprinted” on virtually anything — from people to colored balls — during their first days of life. Such “programming” probably evolved to help young birds recognize and stick close to their parents for safety.

Soon, university officials had set up a special institute where Lorenz and several other scientists could study animal behavior full time. But the work was interrupted by World War II. Lorenz became a military doctor, and was eventually captured by the Russian Army. After years as a prisoner, he returned to Austria in 1948, and was offered funds to resume his work. “We had money to support our animals, no salaries but plenty of enthusiasm and enough to eat,” he recalled. He eventually moved to Germany, where he was offered the chance to create a small research station.

For the next several decades, Lorenz helped pioneer the study of animal behavior, or “ethology.” He wrote several popular books, and soon became known to the public as “the man who walked with geese.” Magazines featured pictures of Lorenz leading, and even swimming with, his imprinted flocks. In 1973 Lorenz, together with two other scientists, was awarded the Nobel Prize for Physiology.

Today, Lorenz’s theory of imprinting is still being fine-tuned by scientists. Among other things, they’ve found that the imprinting window may not be as narrow as once thought. But, in general, Lorenz’s work has stood the test of time. And, as NATURE’s Flight School illustrates, an understanding of imprinting has important implications for conservation.

In the show, for instance, viewers meet Chewy, a gangly young sandhill crane whose parents were killed by a coyote. As a result, he was raised by people, and is imprinted on a woman named Mia. While Mia’s a great mom, Chewy never learned to behave as a normal, well-adjusted crane. As a result, he doesn’t know how to migrate and there’s little chance he’ll ever mate.

For biologists trying to raise and reintroduce endangered birds such as whooping cranes back into the wild, such imprinting gone awry would be a disaster. Conservationists thus go to great lengths to prevent newborn whoopers from imprinting on people. They wear crane costumes whenever they are around the birds, use puppets to feed the chicks, and raise the birds in isolated areas away from people.

So far, the strategy seems to work pretty well. And, eventually, researchers hope that there will be plenty of wild cranes to raise their own young — and biologists won’t have to worry about the behavioral quirk that Konrad Lorenz studied so long ago.