Mustela nigripes (Black-footed Ferret) 

Written by Dan Walker (Mammalogy Lab--Fall 2003)

Edited by Karah Gallagher and Jennifer Bailey

Map prepared by Greg T. Lewellen Historic distribution of black-tailed prairie dog

Mustela nigripes, the black-footed ferret, was formally found throughout the Great Plains of North America (Hillman and Clark 1980).  Ranges included parts or all of Montana, North Dakota, South Dakota, Nebraska, Wyoming, Colorado, Kansas, Utah, Arizona, New Mexico, Oklahoma, and Texas; basically wherever prairie dogs (Cynomys sp.) were found (Hillman and Clark 1980). 

They have long been extirpated from almost all of their range.  It was thought that M. nigripes was extinct in the wild, but an unknown colony was discovered in 1981 near Meeteetse, Wyoming (Forrest et al. 1988).

Physical Characteristics:

M. nigripes is about the size of a mink (Mustela vison).  The upper parts are a yellowish buff, the tip of the tail is black, the feet are black, and a black mask covers the face and eyes.  Underparts are cream colored.  Color is very different from other Mustela sp. 

Size of M. nigripes differs between males and females.  Males have a total length of 570mm, tail 133mm, hind foot 60mm, ear 31mm and a weight of 850-1400g.  Females are 500-120-55-29 and 450-850g (Davis and Schmidly 1994).  Females average about 10% smaller in linear measurements than that of males (Hall and Kelson 1959).  Length of tail is up to 25% of the rest of body and head (Hillman and Clark 1980).

Natural History:

Food Habits: Prairie dogs are essentially the life source for M. nigripes.  A study by Campbell et al. (1987) from 1982 to 1984 found that 87% of their scats contained remains of white-tailed prairie dogs (Cynomys leucurus).  The remains of deer mice (Peromyscus maniculatus), sagebrush voles (Lagurus curtatus), and meadow voles (Microtus montanus) were found in 2% of the scats.  Sheets et al. in 1972 found 90% of scat contained prairie dog remains.  Even though other species are taken occasionally, prairie dogs are a huge part of M. nigripes diet.

Reproduction: M. nigripes mating season is from April to May (Davis and Schmidly 1994).  Gestation lasts 42 to 45 days (Hillman and Clark 1980).  The females will average 3.3 young with an extreme low of 1 and a high of 6.  The young leave their mother in September or early October.  The males disperse great distances while the females usually stay in the mother’s territory (Nowak 1999).  Females sometimes stay to help raise the next litter.  Sexual maturity is attained at 1 year.  The young are called kits.

Behavior: M. nigripes is a solitary animal except during breeding.  They are nocturnal and do not hibernate.  They rarely deposit feces above ground; it is usually deposited in a special chamber inside their burrow.  They are a very vocal species.  They will chatter and hiss whenever threatened (Wilson and Ruff 1999).  The more excited they get, the more intense their calls are (Progulske 1969).

Habitat:  Prairie dog burrow systems are the only habitat for M. nigripes.  They are only found in prairie dog towns.  They use their burrows and add to them.  They will hold dirt against their chest, drag it out, and make a long flat, ever lengthening pile outside the entrance (Davis and Schmidly 1994).  They have been observed digging up to 15 feet of tunnel in one night (Progulske 1969).

No literature was found as to the economic importance of M. nigripes.

Conservation Status:

M. nigripes is the most endangered mammal in North America.  In the 1920s, the population was estimated at 800,000 (Caughley and Gunn 1996).  Due mainly to loss of habitat, their numbers dwindled.  In 1986, the last 18 living M. nigripes were captured and put into a breeding program (Biggins et al. 1998).  Their numbers are rising in captivity and some have been released into the wild.  An estimated survival rate for captive-raised reintroduced individuals was 12-15% (Biggins et al. 1998).  For better survival rates, released M. nigripes should be exposed to quasi-natural environments prior to release (Biggins et al. 1999).  4 month old M. nigripes (the age when they disperse) are more likely to kill on their own if they are given the opportunity to at a younger age.  Time and practice is needed to refine their hunting skills (Vargas and Anderson 1999).

References:

Audubon, J. J., and J. Bachman. 1851. The viviparous quadrupeds of North America. V. G. Audubon, New York, 2: 1-334.

Biggins, Dean E., Astrid Vargas, Jerry L. Godbey, and Stanley H. Anderson. 1999. Influence of prerelease experience on introduced black-footed ferrets (Mustela nigripes). Biological Conservation 89: 121-129.

Biggens, Dean E., Jerry L. Godbey, Louis L. Hanebury, Bob Luce, Paul E. Marinari, Marc R. Matchett, And Astrid Vargas. 1998. The effect of rearing methods on survival of reintroduced black-footed ferrets. The Journal of Wildlife Management 62: 643-653.

Campbell, T. M. III, T. W. Clark, L. Richardson, S. C. Forrest, and B. R. Houston. 1987. Food habits of Wyoming black-footed ferrets. The American Midland Naturalist 117: 208-210.

Caughley, Graeme, and Anne Gunn. 1996. Conservation Biology in Theory and Practice. Blackwell Science, Cambridge Massachusetts.

Davis, William B., and David J. Schmidly. 1994. The Mammals of Texas. University of Texas Press, Austin.

Forrest, Steven C. Dean E. Biggins, Louise Richardson, Tim W. Clark, Thomas M. Campbell III, Kathleen A. Fagerstone, and E. Tom Thorne. 1988. Population attributes for the black-footed ferret (Mustela nigripes) at Meeteetse, Wyoming, 1981-1985. Journal of Mammalogy 69: 261-273.

Hall, E. R., and K. R. Kelson. 1959. The mammals of North America. Ronald Press Co., New York.

Hillman, Conrad N. and Tim W. Clark. 1980. Mustela nigripes. Mammalian Species 126: 1-3.

Nowak, R.M. 1999. Walker's Mammals of the World. 6th Ed. The Johns Hopkins University Press, Baltimore, Maryland.

Progulske, D. R. 1969. Observations of a penned, wild-captured black-footed ferret. Journal of Mammalogy 50: 619-621.

Sheets, R. G., R. L. Linder, and R. B. Dahlgren. 1972. Food habits of two litters of black-footed ferrets in South Dakota. The American Midland Naturalist 87: 249-251.

Vargas, Astrid, and Stanley H. Anderson. 1999. Effects of experience and cage enrichment on predatory skills of black-footed ferrets (Mustela nigripes). Journal of Mammalogy 80: 263-269.

Wilson, Don and Sue Ruff. 1999. The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, District of Columbia.