Threatened and Endangered Species: Black-Footed Ferret Mustela nigripes Fact Sheet

OFFICIAL STATUS: Endangered. Endangered species are species that are in danger of extinction throughout all or a significant portion of their range. It is unlawful to kill, harm, or harass endangered species.

LISTED: 35 Federal Register 8495; June 2, 1970.

HISTORICAL STATUS: Black-footed ferrets once ranged throughout the Great Plains. Populations declined dramatically in the 1980’s. The last known population was found at Meeteetse, Wyoming, in 1981. The remaining 18 individuals from this population were captured and put into a captive breeding facility in 1987.

PRESENT STATUS: From 1987 until 1991 the black-footed ferret may have been extirpated in the wild. In the fall of 1991, 49 captive animals were reintroduced into the wild in Wyoming. The reintroduced animals were designated an “experimental” population. Additional ferrets have been introduced each year since 1991. Unconfirmed sightings from other areas continue to be reported. There are still about 400 black-footed ferrets in captivity. In Montana, parts of Phillips County are targeted for ferret reintroduction.

HABITAT: The black-footed ferret inhabits short grass prairies, always within close proximity to prairie dog towns.

LIFE HISTORY: Black-footed ferrets can breed when 1 year old. Breeding takes place from March to May. Gestation ranges from 41 to 45 days. Typically, there are 3 to 4 young per litter. Young ferrets leave the family group around September. Juvenile males suffer high mortality, a result of their dispersing to new areas. Life expectancies for wild black-footed ferrets are probably less than 5 years.

Prairie dogs comprise 90 percent of the diet of black-footed ferrets. A ferret family of 4 will consume an average 763 prairie dogs per year. These animals utilize prairie dog burrows for shelter and raising families. Black-footed ferrets are primarily nocturnal. They are active in winter.

AID TO IDENTIFICATION: Black-footed ferrets are 20 inches to 24 inches long, including a 6 inch tail, and weigh up to 2-1/2 pounds. They have a yellowish brown body with a distinctive black mask across the face, black on the feet and the tip of the tail. The related long-tailed weasel is about half the size of the ferret and does not have the distinctive black markings.

REASONS FOR DECLINE: The rapid decline of black-footed ferrets has been linked to the eradication of prairie dogs. Prairie dogs now occupy less than 1 percent of their historic range. Canine distemper also can threaten ferret populations.

RECOMMENDATIONS: It is recommended that individuals contact the U.S. Fish and Wildlife Service before initiating activities that affect prairie dog towns. Report any suspected black-footed ferret sightings to a wildlife agency.

COMMENTS: Prairie dogs are essential to blackfooted ferrets. Dog towns provide habitat for other rare species such as mountain plovers, burrowing owls, ferruginous hawks, prairie falcons, swift fox, and game species like antelope.

REFERENCES: Black-footed Ferret Recovery Plan by U.S. Fish and Wildlife Service, 1988. Handbook of Methods for Locating Black-footed Ferrets 1984, and Black-footed Ferret Habitat: Some Management and Reintroduction Considerations 1985, both published by the Wyoming Game and Fish Commission and the U.S. Bureau of Land Management.

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Last Modified: 11/16/2005