35 black-footed ferrets were reintroduced to their historic prairie home in eastern Colorado.
Black-footed ferret 35 black-footed ferrets were reintroduced to their historic prairie home in eastern Colorado. © Chris Prague/The Nature Conservancy

Animals We Protect

Black-footed Ferret

Mustela nigripes

Meet the Black-footed Ferret 

These mainly nocturnal mammals live underground in prairie dog burrows and are quite playful and vocal. They measure 18 to 24 inches long and weigh less than three pounds. The ferret’s yellow-beige color and black markings on its face, feet and tail help it to blend in with its surroundings. It has short legs with large front paws and claws that are adept at digging.

For millennia, black-footed ferrets inhabited a vast swath of North America that spread from Saskatchewan down into the Mexican state of Chihuahua. However, they are specialized predators that live only in prairie dog colonies.

Shaped like tubes of muscle—ferrets have about the same circumference at the neck as at the hips—and armed with impressive teeth, they rarely venture above ground during the daytime. Quick and bold, ferrets dart through the extensive underground passages and dens, killing and devouring a prairie dog every few days. Ferrets have evolved to depend almost exclusively on these rodents and can’t survive without them.


Protecting the Black-footed Ferret

Due to habitat fragmentation and the eradication of the species’ primary food source—prairie dogs—biologists feared the ferrets had gone extinct in the 1970s. Then, in 1981, a rancher’s dog in Wyoming brought home a ferret it had killed. This led to the discovery of a small number of ferrets nearby.

From only seven breeding ferrets, conservationists re-established their numbers and began releasing them into the wild.

From 1996 to 1999, 147 black-footed ferrets were released in South Dakota’s Conata Basin, an area where the species had existed historically, and the population began to slowly grow.

Unfortunately, in 2008, sylvatic plague was discovered in Conata Basin. The Nature Conservancy, U.S. Fish & Wildlife Service, National Park Service, U.S. Forest Service and Prairie Wildlife Research crews were able to save some of the ferrets by vaccinating them and dusting the prairie dog holes with insecticide to slow the spread of the fleas that carry the plague. 

Today about 80 ferrets remain at Conata Basin.

Ferrets remain critically endangered with an approximated 200-300 now living in the wild at 27 sites across the US. That may sound like a small number, but with a stable captive population and evidence of breeding in the wild, this is a huge success for a species that nearly vanished.

Discover other incredible endangered species recovery efforts.