Articles By Della Garell BFF species coordinator:

2000 AZA Annual Report

Communiqué Article December 2002

CLASSIFICATION:
    PHYLUM:  Chordata
    CLASS:   Mammalia
    ORDER:   Carnivora
    FAMILY:   Mustelidae
    SUBFAMILY:   Mustelinae

HISTORY:

    The black-footed ferret is a critically endangered animal, and was listed as an endangered species in 1967.  The black-footed ferret was thought to be extinct in the late 1970's but a small population was discovered near Meeteetse, WY in 1981.  In 1985, the ferret population began to decline due to canine distemper and sylvatic plague, which was also affecting their main prey food, prairie dogs.  Sylvatic plague (Yersinia pestis) is another significant threat to long-term survival in the wild.  Not only does an outbreak quickly and drastically eliminate the ferret’s prey base, the prairie dog; black-footed ferrets are fatally susceptible to as little as one fleabite dose of this widespread disease. In an effort to save the species, the last eighteen ferrets from this remnant population were captured between 1985 and 1987.  Only seven of the eighteen animals that were captured reproduced founders for what is now the stable population.

DISTRIBUTION:
   The black-footed ferret lives in a variety of places including Arizona, Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah, Wyoming and the Canadian Provinces of Alberta and Saskatchewan.  The black-footed ferret is the only ferret that is native to North America.

                                  Map of known refuges for the black-footed ferret.

PHYSICAL CHARACTERISTICS:
   The black-footed ferret is thought to have been descended from the Siberian polecat.  The black-footed ferret's coat is generally white or buff with areas of light to dark brown; this darker coloring is usually along the back.  The amount of brown coloring will vary depending on the individual and the season.  The top of its head and forehead are always dark brown.  It has a black face mask, black legs, and a black tail tip.  Within its black face mask is a prominent white brow spot above the border of each eye.  The black-footed ferret grows to a length of 20-24 inches including a 5-6 inch tail and weighs up to 2 1/2 pounds.  Males are slightly larger than the females.  It's body is long and slender with short legs.  The black-footed ferret has large front feet that it uses for digging.  A distinguishing feature of the black-footed ferret is cleft chin.

DIET:
  The black-footed ferret is a predator and over 90% of its diet consists of prairie dogs.  It may also eat mice, ground squirrels, rabbits, rats, birds and occasionally insects and reptiles. The black-footed ferret kills by attacking its prey by the neck and base of the skull.  They then cache the food to feed on at a later time. Food requirements vary seasonally and individually.  In captivity, black-footed ferrets have been found to consume one prairie dog for every 3 to 4 days.

 REPRODUCTION:
   The black-footed ferret breeds in March and April.  During this mating season, the females aggressively solicit the males.  Black-footed ferrets have delayed implantation, where the fertilized egg does not implant immediately.  Development of the embryo will not start until optimal weather conditions exist.  Once implantation occurs, its gestation period is between 35 to 45 days.  The black-footed ferret kits are born approximately one half to three quarters the adult size.  Rearing of the young is left to the female.  The females become sexually mature at one year of age.  Their lifespan in the wild is believed to be less than five years, with few actually making it to the age of four.  However, in captivity, where they are not subject to the hard life of the wild or predation, they have been known to live up to nine years of age.

                                                 (Four Black-Footed Ferret kits)

                                         Compliments of Wyoming Game and Fish Department

BEHAVIOR:
   The black-footed ferret is nocturnal, being active mostly during the night.  During the winter months, they reduce their activity levels, occasionally remaining underground for 5 to 6 days consecutively.  They are solitary animals and are very territorial.  Black-footed ferrets will aggressively defend their territory against other same sex competitors.  They also use urination and defecation for scent marking to maintain their dominance hierarchies, as well as mark their territories. Black-footed ferrets use the abandoned burrows of prairie dogs for shelter and denning.
    These burrows are essential for them; they provide protection from their predators and a safe place for them to sleep and eat.  These burrows are used to shield them from varying temperature ranges and inclement weather.  Within these burrows, the females will breed and rear their young.

HABITAT:
   Black-footed ferrets inhabit the rolling hills and short grass prairies of North America.  On the average, each black-footed ferret needs 100 to 120 acres of space for it to forage for food.  A mother with a litter of three kits would need roughly 140 acres to survive.

STATUS:
    In 1967 the U.S. Fish and Wildlife service declared the black footed ferret endangered. This is due in part to the widespread poisoning of prairie dogs and the agricultural clearing of their habitat in the last century.  The severe decline of the prairie dogs nearly caused the extinction of black-footed ferrets.  Other factors that attribute to the black-footed ferrets decline were secondary poisoning from prairie dog toxicants and canine distemper.  The black-footed ferrets numbers dropped to an incredible 31 in 1985 but have been gradually improving due to captive breeding and recovery programs, as well as reintroduction into the wild from these captive populations. 

REFERENCES:
Compton’s Interactive Encyclopedia Deluxe, 1998.  The Learning Company, Inc.

Federal Register:  Volume 60, Number 220, November 15, 1995.  “Endangered and Threatened Wildlife and Plants:  Proposed Establishment of a nonessential Experimental Population of black-Footed ferrets in Aubrey Valley, Arizona.”

New Standard Encyclopedia, Volume 6, 1987.  Standard Educational Corporation, Chicago, IL

Society for the Protection and Conservation of the Black-Footed Ferret, 1996.   “History of the Black-Footed Ferret."

  Wyoming Game & Fish Department - Black-footed Ferret Information

  U.S. Fish & Wildlife Services Fact Sheet - Black-footed Ferret