What it is
The black-footed ferret (Mustela nigripes) is a slim weasel of the North American prairie with a pale buff coat, a black mask across the eyes and black feet. Prairie dogs make up most of its food, and it lives in their burrows. The International Union for Conservation of Nature lists it as Endangered.
Range
Once the Great Plains from southern Canada to northern Mexico, now reintroduced colonies in Wyoming, South Dakota, Montana and Arizona.
What happened
Black-footed ferrets were thought to be extinct until a ranch dog brought a dead one home near Meeteetse, Wyoming, in 1981. That last wild colony was then hit by plague and distemper, and between 1985 and 1987 the survivors were caught to start a breeding programme. Young ferrets from the programme have been released ever since, about 4,500 so far.
When / status
Endangered now, living wild only where it has been released.
Human role
Loss of the prairie dog colonies it needs for food and shelter, and the diseases plague and distemper, threaten it.