Twenty-eight years ago, a Wyoming rancher's dog carried a strange-looking dead animal home to its master.
The cream-coloured creature was about the size of a house cat, with a slim body and black feet, face and tail tip. Puzzled, the rancher took it to wildlife biologists, who were stunned to discover an animal thought extinct: a black-footed ferret.
Further examination revealed that the rancher's property was home to a small, stable population of these ferrets. But six years later, disease cut their numbers to just 18 and panicked biologists raced to round up the remaining animals, rightly suspecting that they would never find others.
Now, the process is being reversed: This fall, the black-footed ferret will return to Saskatchewan, where it hasn't been seen since the 1930s, when settlers converted prairie to farms, decimating the ferret's prairie dog prey.
While the ferrets have already been reintroduced to Wyoming and other places in the United States and Mexico, this will mark a first in Canada. Most of the 40 animals to be released in Grasslands National Park will come from the Toronto Zoo, which runs one of six captive breeding programs set up across North America two decades ago.
But before being given their freedom, the animals must receive something crucial to their success in the wild: survival training.
The black-footed ferrets have to go to boot camp.
“It's pretty essential for pre-conditioning,” says Maria Franke, the Toronto Zoo's curator of mammals.
The problem of how to “re-wild” animals bred in captivity is cause for much hand-wringing these days as habitat destruction forces more creatures onto endangered-species lists. Animals raised with regular meals and nary a predator in sight simply can't be let loose to fend for themselves. They need to learn how to hunt for their own food and find shelter. The hardest part for most is recognizing and escaping those animals that want to make a meal out of them.
The Toronto Zoo's young ferrets will be flown next month to the U.S. Geological Survey's facility in Fort Collins, Colo., where they will live with their mothers for six to eight weeks in large, closed outdoor pens.
Boot camp is crucial, as biologists learned after their first disastrous attempt at reintroduction in Wyoming in 1991. The black-footed ferret was taken straight from captivity into the wild and nearly every ferret died in the first year, mostly in the jaws of coyotes and badgers.
But a series of trial-and-error experiments led by wildlife biologist Dean Biggins of the U.S. Geological Survey has since produced today's regimen for toughening up the creatures. Unwilling to risk the few remaining ferrets, Mr. Biggins brought Siberian polecats from China – the ferrets' closest living relatives – to act as stand-ins for testing boot-camp techniques.
He raised the polecats in the same one-by-1.2-metre cages in which the ferrets were first reared, testing their reactions to mock predators, including the rather disappointing robo-badger.
“He was a road-kill badger mounted on a toy truck chassis and we'd chase them around with it. But robo-badger was slow and although he looked like a badger, he just didn't behave like one,” Mr. Biggins admits.
So a more convincing stuffed owl was rigged to swoop down when the polecats passed through an infrared trip line.
The first generation fled to their boxes, where they cowered for hours. But each successive generation became less wary and by the fourth generation very little spooked them.
While the results were no surprise, Mr. Biggins hoped that his next experiment would show that the unwary behaviour was reversible and not genetically hardwired. He wanted his next experiment to show that by taking that fourth generation and raising them in large pens that simulated their natural environment, their offspring would eventually relearn how to be wary and avoid predators.
He created as normal a habitat as possible while still offering protection from predators so that the animals could live long enough to unlearn bad habits. To his relief, each successive generation became increasingly wary, until their reactions were close to normal.
“Why that happened, we don't know,” Mr. Biggins says. “Was it simply lack of human attention? Or being in burrows where mom can transmit escape behaviour? Or are they more physically fit?”
