Black-Footed Ferrets Fight Extinction

The ferrets that will be released into the wild are put in outdoor "pre-conditioning" pens. A concrete wall extends down into the ground to keep them from escaping.

Twenty-five years ago today, a dog in Wyoming arrived at its owner's doorstep with a dead black-footed ferret in its mouth. Until then, biologists had thought the species was extinct.

Within a few years, biologists found 17 more ferrets and started a captive-breeding program. There are now hundreds of these ferrets in the wild today, but they are still considered one of the most endangered mammals in North America.

The National Black-footed Ferret Conservation Center, located about 60 miles north of Denver, is trying to save the species. The center breeds several hundred kits, or infant black-footed ferrets, every year. The ferrets, with their long bodies and mottled fur, are often mistaken for pets.

"A lot of folks confuse them with the domestic ferret," says Paul Marinari, a wildlife biologist with the United States Fish and Wildlife Services. "[But] these guys are a totally different species. This is the only native ferret to North America."

Though native to the region, the ferrets are not comfortable navigating the world outside their breeding cages. At 4 months old, most of the kits are released onto selected prairies throughout the region, where they spend a month in large cages to acclimate them to their surroundings. Though biologists have tried to show the ferrets which predators they should fear, the approach has not always been effective.

"We had this thing called Robo-Badger. It was this mechanized badger that we would drive around the pens to try and scare the ferrets," says Marinari. "And, you know, when the ferrets started riding on the back of the badger, we kind of thought, 'Well, let's move to something else...'"

Inside the conservation facility, Marinari points to a ferret poking its head up out of plastic tubing on the bottom of its cage.

"She’s doing something -- what we call periscoping," he says. "And that's a behavior that you often see in the wild, where a ferret would pop its head up out of a prairie-dog burrow and, basically, turn around and take in the entire scene, like a submarine periscope."

Ferrets live in prairie-dog burrows. Ranchers killed many of these prairie dogs 70 years ago to make way for grazing cattle, and both the prairie dog and the ferret received protection under the Endangered Species Act. Prairie dogs, however, have recovered much more quickly than ferrets. Ranchers now say there are too many prairie dogs on the plain.

Kevin Kruse grazes cattle on national grasslands in the South Dakota Conata Basin. He says the prairie dogs have changed the ecosystem.

"It looks more like a parking lot than it does like a grassland," he says. "When the wind blows hard, the dust rises in the air -- sometimes 50 to 100 feet."

The Forest Service, which manages the grassland, is considering poisoning more prairie dogs to appease the ranchers. Jonathon Proctor, who works for Defenders of Wildlife, an endangered species organization, says this would also destroy the black-footed ferret population.

"If we won't allow an endangered species -- the black-footed ferret -- and its important habitat -- the black-tailed prairie dog colonies -- to survive in this one spot, without destroying them, exactly where are we going to let them survive?" he asks.

The Forest Service is set to decide the prairie-dog-poisoning issue over the next year. Biologists in Colorado, meanwhile, say it will be years before a viable population of black-footed ferrets is established in the wild.

Copyright 2023 NPR. To see more, visit https://www.npr.org.