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Black-footed Ferret - Mustela nigripes
State Rank Reason (see State Rank above)
Species was previously extirpated from the state due to direct and indirect persecution and prairie dog eradication efforts. Reintroduction efforts have largely been unsuccessful to Sylvatic Plague with only a handful of captive reared individuals remaining at reintroductions sites.
Black-footed Ferret (Mustela nigripes ) Conservation Status Summary
State Rank: S1
Review Date = 09/25/2024
How we calculate Conservation Status
Rarity:
Very Uncommon Very Common
Threats:
Highly Threatened Unthreatened
Trends:
Rapidly Declining Declining Stable Increasing
Rank:
S1
S2
S3
S4
S5
Critically Imperiled Secure
See the complete
Conservation Status Report
General Description
Black-footed Ferrets are weasel-like in body shape and form but are heavier than other weasels. The torso is long with short legs and a long tail. The color of the body is a soft cream color with the ears, chin and throat fading to white. The dorsal portion of the torso is darker than the rest of the body. The legs and tip of the tail are dark brown and a mask of the same color extends in a band from below each eye across the forehead.
Diagnostic Characteristics
Although similar in size and shape to the American Mink (Mustela vison ), the much lighter body color and prairie habitat of the Black-footed Ferret are distinctive. Long-tailed Weasels (Mustela frenata ) are smaller and less robust and do not have the distinctive black mask and feet of the ferret.
Species Range
Montana Range
Range Descriptions Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
Number of Observations: 65
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
Relative Density
Recency
(Observations spanning multiple months or years are excluded from time charts)
Migration
Black-footed Ferrets are not known to migrate. Juveniles disperse in September. Adults use about a 100-acre range semi-nomadically (Richardson 1986).
Habitat
Black-footed Ferrets are intimately tied to prairie dogs (Cynomys spp.) throughout their range and have only been found in association with prairie dogs. They are therefore limited to the same open habitat used by prairie dogs: grasslands, steppe, and shrub steppe. Black-footed Ferrets do not dig their own burrows and rely on abandoned prairie dog burrows for shelter. Only large complexes (several thousand acres of closely spaced colonies) can support and sustain a breeding population of Black-footed Ferrets. It has been estimated that about 40 to 60 hectares of prairie dog colony is needed to support one Black-footed Ferret, and females with litters have never been found on colonies less than 49 hectares (Miller et al. 1996). Black-footed Ferrets scent-mark to maintain spatial separation (Richardson 1986).
Ecological Systems Associated with this Species
Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system,
even if point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at:
mtnhp.org/requests ) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
Literature Cited
Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
Food Habits
Prairie dogs are an important food source; one study found prairie dog remains in 91% of analyzed Black-footed Ferret scats (Hillman and Clark 1980). Alternate prey such as ground squirrels, rabbits, voles and mice are probably eaten opportunistically.
Ecology
Black-footed Ferrets eat and defecate underground. They sometimes drag prey more than 1000 feet in winter. They travel an average of 1 mile per night. They do not adopt one "den burrow" and are semi-nomadic, traveling from burrow to burrow (Richardson 1986).
Reproductive Characteristics
No specific information on Black-footed Ferret reproductive biology is available for Montana, but in other portions of their range copulation occurred in March and early April. Gestation is 42 and 45 days (Foresman 2012). Wild-born litter sizes in South Dakota averaged 3.5 (range 1 to 5) (Hillman and Clark 1980), and 3.3 at emergence in Wyoming (Forrest et al. 1988). Young are born underground in prairie dog burrows. Young appear above ground usually in July and disperse in fall. At least some females reproduce as yearlings (Forrest et al. 1988).
Management
Black-footed Ferrets have been extirpated from most of their former large range mainly as a result of prairie dog and predator control programs. Canine distemper, in conjunction with captures for captive breeding, resulted in extirpation of the last known wild population near Meeteetse, Wyoming by early 1987. See Miller et al. (1996) for more information on the discovery of the Meeteetse population and subsequent distemper-caused decline and captive breeding decisions that occurred in 1985. All known populations are a result of the reintroduction of captive bred Black-footed Ferrets from animals taken into captivity from this population. Reintroductions have occurred annually in Montana on federal and/or tribal land since 1994 with varying success. Predation by Coyotes and Badgers, and long distance dispersal have been the primary problems with the reintroduction efforts, but plague
(Yersinia pestis ) has also apparently resulted in deaths for released animals. Some wild reproduction has occurred but no self-sustaining populations have been established yet.
Additional information on the biology and management of Black-footed Ferret populations can be found on the U.S. Fish and Wildlife Service's
Environmental Conservation Online System Species Profile Stewardship Responsibility
References
Literature Cited AboveLegend: Mustela nigripes ) at Meeteetse, Wyoming, 1981-1985. Journal of Mammalogy 69:261-273.Mustela nigripes . American Society of Mammalogists, Lawrence, KS. Mammalian Species Number 126:1-3. Additional ReferencesLegend: Do you know of a citation we're missing? Mustela nigripes ). Wildlife Preservation Trust, Special Scientific Report No. 3. 175 p.Effects of recreation on Rocky Mountain wildlife: a review for Montana . [Montana]: Montana Chapter of the Wildlife Society. Web Search Engines for Articles on "Black-footed Ferret"
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