Black-footed ferret

The black-footed ferret (Mustela nigripes), also known as the American polecat[2] or prairie dog hunter,[3] is a species of mustelid native to central North America. It is listed as endangered by the IUCN, because of its very small and restricted populations. First discovered by Audubon and Bachman in 1851, the species declined throughout the 20th century, primarily as a result of decreases in prairie dog populations and sylvatic plague. It was declared extinct in 1979 until Lucille Hogg's dog brought a dead black-footed ferret to her door in Meeteetse, Wyoming in 1981.[4] That remnant population of a few dozen ferrets lasted there until the animals were considered extinct in the wild in 1987. However, a captive breeding program launched by the United States Fish and Wildlife Service resulted in its reintroduction into eight western states, Canada and Mexico from 1991 to 2009. There are now over 1,000 mature, wild-born individuals in the wild across 18 populations, with five self-sustaining populations in South Dakota (two), Arizona, Wyoming and Saskatchewan.[1][5] It was first listed as "Endangered" in 1982, then listed as "Extinct in the Wild" in 1996 before being downgraded back to "Endangered" in 2008.[6]

The black-footed ferret is roughly the size of a mink, and differs from the European polecat by the greater contrast between its dark limbs and pale body and the shorter length of its black tail-tip. In contrast, differences between the black-footed ferret and the steppe polecat of Asia are slight, to the point where the two species were once thought to be conspecific.[7] The only noticeable differences between the black-footed ferret and the steppe polecat are the former's much shorter and coarser fur, larger ears, and longer postmolar extension of the palate.[8]

It is largely nocturnal and solitary, except when breeding or raising litters.[9][10] Up to 91% of its diet is composed of prairie dogs.[11][12]

Black-footed ferret
Mustela nigripes 2
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Mustela
M. nigripes
Binomial name
Mustela nigripes
(Audubon & Bachman, 1851)
Black-footed Ferret area
Black-footed ferret range (three small areas on US territory)


Like its close cousin, the Asian steppe polecat (with which it was once thought to be conspecific), the black-footed ferret represents a more progressive form than the European polecat in the direction of carnivory.[2] The black-footed ferret's most likely ancestor was Mustela stromeri (from which the European and steppe polecat are also derived), which originated in Europe during the Middle Pleistocene.[13] Molecular evidence indicates that the steppe polecat and black-footed ferret diverged from Mustela stromeri sometime between 500,000 and 2,000,000 years ago, perhaps in Beringia. The species appeared in the Great Basin and the Rockies by 750,000 years ago. The oldest recorded fossil find originates from Cathedral Cave, White Pine County, Nevada, and dates back to 750,000–950,000 years ago.[14] Prairie dog fossils have been found in six sites where ferrets are yielded, thus indicating that the association between the two species is an old one.[7] Anecdotal observations and 42% of examined fossil records indicated that any substantial colony of medium- to large-sized colonial ground squirrels, such as Richardson's ground squirrels, may provide a sufficient prey base and a source of burrows for black-footed ferrets. This suggests that the black-footed ferret and prairie dogs did not historically have an obligate predator-prey relationship.[14] The species has likely always been rare, and the modern black-footed ferret represents a relic population. A reported occurrence of the species is from a late Illinoian deposit in Clay County, Nebraska, and is further recorded from Sangamonian deposits in Nebraska and Medicine Hat. Fossils have also been found in Alaska dating from the Pleistocene.[7][13]


Skull, as illustrated in Merriam's Synopsis of the weasels of North America
Black-footed Ferret 001
Black-footed ferret at the Louisville Zoo

The black-footed ferret has a long slender body with black outlines such as the feet, ears, parts of the face and its tail. The forehead is arched and broad, and the muzzle is short. It has few whiskers, and its ears are triangular, short, erect and broad at the base. The neck is long and the legs short and stout. The toes are armed with sharp, very slightly arched claws. The feet on both surfaces are covered in hair, even to the soles, thus concealing the claws.[15] It combines several physical features common in both members of the subgenus Gale (least, short-tailed and long-tailed weasels) and Putorius (European and steppe polecats). Its skull resembles that of polecats in its size, massiveness and the development of its ridges and depressions, though it is distinguished by the extreme degree of constriction behind the orbits where the width of the cranium is much less than that of the muzzle. Although similar in size to polecats, its attenuate body, long neck, very short legs, slim tail, large orbicular ears and close-set pelage is much closer in conformation to weasels and stoats.[16] The dentition of the black-footed ferret closely resembles that of the European and steppe polecat, though the back lower molar is vestigial, with a hemispherical crown which is too small and weak to develop the little cusps which are more apparent in polecats.[16]

Males measure 500–533 millimetres (19.7–21.0 in) in body length and 114–127 millimetres (4.5–5.0 in) in tail length, thus constituting 22–25% of its body length. Females are typically 10% smaller than males.[7] It weighs 650–1,400 grams (1.43–3.09 lb).[17] Captive-bred ferrets used for the reintroduction projects were found to be smaller than their wild counterparts, though these animals rapidly attained historical body sizes once released.[18]

The base color is pale yellowish or buffy above and below. The top of the head and sometimes the neck is clouded by dark-tipped hairs. The face is crossed by a broad band of sooty black, which includes the eyes. The feet, lower parts of the legs, the tip of the tail and the preputial region are sooty-black. The area midway between the front and back legs is marked by a large patch of dark umber-brown, which fades into the buffy surrounding parts. A small spot occurs over each eye, with a narrow band behind the black mask. The sides of the head and the ears are dirty-white in color.[8]

Behavior and ecology

Territorial behavior

Jumping black footed ferret
Black-footed ferret performing a weasel war dance

The black-footed ferret is solitary, except when breeding or raising litters.[9][10] It is nocturnal[9][19] and primarily hunts for sleeping prairie dogs in their burrows.[20] It is most active above ground from dusk to midnight and 4 a.m. to mid-morning.[12] Aboveground activity is greatest during late summer and early autumn when juveniles become independent.[12] Climate generally does not limit black-footed ferret activity,[10][12] but it may remain inactive inside burrows for up to 6 days at a time during winter.[21]

Female black-footed ferrets have smaller home ranges than males. Home ranges of males may sometimes include the home ranges of several females.[10] Adult females usually occupy the same territory every year. A female that was tracked from December to March occupied 39.5 acres (16 ha). Her territory was overlapped by a resident male that occupied 337.5 acres (137 ha) during the same period. The average density of black-footed ferrets near Meeteetse, Wyoming, is estimated at 1 black-footed ferret /99 to 148 acres (60 ha). As of 1985, 40 to 60 black-footed ferrets occupied a total of 6,178 to 7,413 acres (2,500 to 3,000 ha) of white-tailed prairie dog habitat.[9] From 1982 to 1984, the average year-round movement of 15 black-footed ferrets between white-tailed prairie dog colonies was 1.6 miles/night (2.5 km) (with a spread of 1.1 miles or 1.7 km). Movement of black-footed ferrets between prairie dog colonies is influenced by factors including breeding activity, season, sex, intraspecific territoriality, prey density, and expansion of home ranges with declining population density.[10][22] Movements of black-footed ferrets have been shown to increase during the breeding season; however, snow-tracking from December to March over a 4-year period near Meeteetse, Wyoming revealed that factors other than breeding were responsible for movement distances.[10]

Temperature is positively correlated with distance of black-footed ferret movement.[10] Snow-tracking from December to March over a 4-year period near Meeteetse, Wyoming, revealed that movement distances were shortest during winter and longest between February and April, when black-footed ferrets were breeding and white-tailed prairie dogs emerged from hibernation. Nightly movement distance of 170 black-footed ferrets averaged 0.87 miles (1.40 km) (range 0.001 to 6.91 miles (0.0016 to 11.1206 kilometres)). Nightly activity areas of black-footed ferrets ranged from 1 to 337.5 acres (0 to 137 ha)), and were larger from February to March (110.2 acres (45 ha)) than from December to January (33.6 acres (14 ha)).[10] Adult females establish activity areas based on access to food for rearing young. Males establish activity areas to maximize access to females, resulting in larger activity areas than those of females.[10]

Prey density may account for movement distances. Black-footed ferrets may travel up to 11 miles (18 km) to seek prey, suggesting that they will interchange freely among white-tailed prairie dog colonies that are less than 11 miles (18 km) apart. In areas of high prey density, black-footed ferret movements were nonlinear in character, probably to avoid predators.[10] From December to March over a 4-year study period, black-footed ferrets investigated 68 white-tailed prairie dog holes per 1 mile (1.6 km) of travel/night. Distance traveled between white-tailed prairie dog burrows from December to March averaged 74.2 feet (22.6 m) over 149 track routes.[10]

Reproduction and development

Black footes ferret pups
Black-footed ferret kits

The reproductive physiology of the black-footed ferret is similar to that of the European polecat and the steppe polecat. It is probably polygynous, based on data collected from home range sizes, skewed sex ratios, and sexual dimorphism.[10][22] Mating occurs in February and March.[10][21] When a male and female in estrus encounter each other, the male sniffs the genital region of the female, but does not mount her until after a few hours have elapsed, which is contrast to the more violent behavior displayed by the male European polecat. During copulation, the male grasps the female by the nape of the neck, with the copulatory tie lasting from 1.5–3 hours.[7] Unlike other mustelids, the black-footed ferret is a habitat specialist with low reproductive rates.[22] In captivity, gestation of black-footed ferrets lasts 42–45 days. Litter size ranges from 1–5 kits.[19] Kits are born in May and June[23] in prairie dog burrows.[9] Kits are altricial and are raised by their mother for several months after birth. Kits first emerge above ground in July, at 6 weeks old.[12][22][23] They are then separated into individual prairie dog burrows around their mother's burrow.[12] Kits reach adult weight and become independent several months following birth, from late August to October.[12][22] Sexual maturity occurs at one year of age.[12]

Intercolony dispersal of juvenile black-footed ferrets occurs several months after birth, from early September to early November. Dispersal distances may be short or long. Near Meeteetse, Wyoming, 9 juvenile males and 3 juvenile females dispersed 1 to 4 miles (1.6 to 6.4 kilometres) following litter breakup. Four juvenile females dispersed a short distance (<0.2 miles (0.32 km)) but remained on their natal area.[22]


Black-footed Ferret Learning to Hunt
Black-footed ferret chasing prairie dog.

Up to 90% of the black-footed ferret's diet is composed of prairie dogs.[11][12] The diet of the black-footed ferret varies depending on geographic location. In western Colorado, Utah, Wyoming, and Montana, black-footed ferrets historically associated with white-tailed prairie dogs and were forced to find alternative prey when white-tailed prairie dogs entered their four-month hibernation cycle.[19] In Wyoming, alternative prey items consumed during white-tailed prairie dog hibernation included voles (Microtus spp.) and mice (Peromyscus spp. and Mus spp.) found near streams. In South Dakota, black-footed ferrets associate with black-tailed prairie dogs. Because black-tailed prairie dogs do not hibernate, little seasonal change in black-footed ferret diet is necessary.[10][19]

Black-footed ferret skeleton
Skeletons of black-footed ferret (left) and prairie dog (right) articulated to show the predator-prey relationship between the two. (Museum of Osteology)

In Mellette County, South Dakota, black-tailed prairie dog remains occurred in 91% of 82 black-footed ferret scats. Mouse remains occurred in 26% of scats. Mouse remains could not be identified to species; however, deer mice, northern grasshopper mice, and house mice were captured in snap-trap surveys. Potential prey items included thirteen-lined ground squirrels, plains pocket gophers, mountain cottontails, upland sandpipers, horned larks, and western meadowlarks.[12]

Based on 86 black-footed ferret scats found near Meeteetse, Wyoming, 87% of black-footed ferret diet was composed of white-tailed prairie dogs. Other food items included deer mice, sagebrush voles, meadow voles, mountain cottontails, and white-tailed jackrabbits. Water is obtained through consumption of prey.[9]

A study published in 1983 modeling metabolizable energy requirements estimated that one adult female black-footed ferret and her litter require approximately 474 to 1,421 black-tailed prairie dogs per year or 412 to 1,236 white-tailed prairie dogs per year for sustenance. They concluded that this dietary requirement would require protection of 91 to 235 acres (37 to 95 ha) of black-tailed prairie dog habitat or 413 to 877 acres (167 to 355 ha) of white-tailed prairie dog habitat for each female black-footed ferret with a litter.[24]

Distribution and habitat

The historical range of the black-footed ferret was closely correlated with, but not restricted to, the range of prairie dogs (Cynomys spp.). Its range extended from southern Alberta and southern Saskatchewan south to Texas, New Mexico, and Arizona.[7] As of 2007, the only known wild black-footed ferret population was located on approximately 6,000 acres (2,400 hectares) in the western Big Horn Basin near Meeteetse, Wyoming.[9][10][11][21][22] Since 1990, black-footed ferrets have been reintroduced to the following sites: Shirley Basin, Wyoming; UL Bend National Wildlife Refuge and Fort Belknap Indian Reservation, Montana; Conata Basin/Badlands, Buffalo Gap National Grassland, and the Cheyenne River Sioux Reservation in South Dakota; Aubrey Valley, Arizona; Rocky Mountain Arsenal National Wildlife Refuge and Wolf Creek in Colorado; Coyote Basin, straddling Colorado and Utah, northern Chihuahua, Mexico,[23] and Grasslands National Park, Canada [25]

Historical habitats of the black-footed ferret included shortgrass prairie, mixed-grass prairie, desert grassland, shrub steppe, sagebrush steppe,[22] mountain grassland, and semi-arid grassland.[7] Black-footed ferrets use prairie dog burrows for raising young, avoiding predators, and thermal cover.[9][12] Six black-footed ferret nests found near Mellette County, South Dakota, were lined with buffalo grass, prairie threeawn, sixweeks grass, and cheatgrass. High densities of prairie dog burrows provide the greatest amount of cover for black-footed ferrets.[9][10] Black-tailed prairie dog colonies contain a greater burrow density per acre than white-tailed prairie dog colonies, and may be more suitable for the recovery of black-footed ferrets.[9] The type of prairie dog burrow may be important for occupancy by black-footed ferrets. Black-footed ferret litters near Meeteetse, Wyoming, were associated with mounded white-tailed prairie dog burrows, which are less common than non-mounded burrows. Mounded burrows contain multiple entrances and probably have a deep and extensive burrow system that protects kits.[9] However, black-footed ferrets used non-mounded prairie dog burrows (64%) more often than mounded burrows (30%) near Meeteetse, Wyoming.[10]


Primary causes of mortality include habitat loss, human-introduced diseases, and indirect poisoning from prairie-dog control measures.[12][19][21][23] Annual mortality of juvenile and adult black-footed ferrets over a 4-year period ranged from 59% to 83% (128 individuals) near Meeteetse, Wyoming.[22] During fall and winter, 50% to 70% of juveniles and older animals perish.[22] Average lifespan in the wild is probably only one year but may be up to five years. Males have higher rates of mortality than females because of longer dispersal distances when they are most vulnerable to predators.[22]

Given an obligate-dependence of black-footed ferrets on prairie dogs, black-footed ferrets are extremely vulnerable to prairie dog habitat loss. Habitat loss results from agriculture, livestock use, and other development.[23]

Black-footed ferrets are susceptible to numerous diseases. They are fatally susceptible to canine distemper virus,[7][22] introduced by striped skunks, common raccoons, red foxes, coyotes, and American badgers.[21] A short-term vaccine for canine distemper is available for captive black-footed ferrets, but no protection is available for young born in the wild. Black-footed ferrets are also susceptible to rabies, tularemia, and human influenza. They can directly contract sylvatic plague (Yersinia pestis), and epidemics in prairie dog towns may completely destroy the ferrets' prey base.[26]

Predators of black-footed ferrets include golden eagles, great horned owls, coyotes, American badgers, bobcats, prairie falcons, ferruginous hawks, and prairie rattlesnakes.[12][21][22]

Oil and natural gas exploration and extraction can have detrimental impacts on prairie dogs and black-footed ferrets. Seismic activity collapses prairie dog burrows. Other problems include potential leakages and spills, increased roads and fences, increased vehicle traffic and human presence, and an increased number of raptor perching sites on power poles. Traps set for coyotes, American mink, and other animals may harm black-footed ferrets.[11]


Native American tribes, including the Crow, Blackfoot, Sioux, Cheyenne, and Pawnee, used black-footed ferrets for religious rites and for food.[19] The species was not encountered during the Lewis and Clark Expedition, nor was it seen by Nuttall or Townsend, and it was not until it was first described in Audubon and Bachman's Viviparous Quadrupeds of North America in 1851 that it became known to the scientific world.[27]

It is with great pleasure that we introduce this handsome new species; ... [it] inhabits the wooded parts of the country to the Rocky Mountains, and perhaps is found beyond that range... When we consider the very rapid manner in which every expedition that has crossed the Rocky Mountains, has been pushed forward, we cannot wonder that many species have been entirely overlooked... The habits of this species resemble, as far as we have learned, those of [the European polecat]. It feeds on birds, small reptiles and animals, eggs, and various insects, and is a bold and cunning foe to the rabbits, hares, grouse, and other game of our western regions.

— Audubon and Bachman (1851)[27]


For a time, the black-footed ferret was harvested for the fur trade, with the American Fur Company having received 86 ferret skins from Pratt, Chouteau, and Company of St. Louis in the late 1830s. During the early years of predator control, black-footed ferret carcasses were likely discarded, as their fur was of low value. This likely continued after the passing of the Endangered Species Act of 1973, for fear of reprisals. The large drop in black-footed ferret numbers began during the 1800s through to the 1900s, as prairie dog numbers declined because of control programs and the conversion of prairies to croplands. Sylvatic plague, a disease caused by Yersinia pestis introduced into North America, also contributed to the prairie dog die-off, though ferret numbers declined proportionately more than their prey, thus indicating other factors may have been responsible. Plague was first detected in South Dakota in a coyote in 2004, and then in ~50,000 acres of prairie dogs on Pine Ridge Reservation in 2005. Thereafter 7,000 acres of prairie dog colonies were treated with insecticide (DeltaDust) and 1,000 acres of black-footed ferret habitat were prophylactically dusted in Conata Basin in 2006–2007. Nevertheless, plague was proven in ferrets in May 2008. Since then each year 12,000 acres of their Conata Basin habitat is dusted and about 50–150 ferrets are immunized with plague vaccine.[28] Inbreeding depression may have also contributed, as studies on black-footed ferrets from Meeteetse, Wyoming revealed low levels of genetic variation. Canine distemper devastated the Meeteetse ferret population in 1985. A live virus vaccine originally made for domestic ferrets killed large numbers of black-footed ferrets, thus indicating that the species is especially susceptible to distemper.[17]

Reintroduction and conservation

Southdakota2008 860
Ferret in the wild, July 2008

The black-footed ferret is an example of a species which benefits from strong reproductive science.[29] A captive-breeding program was initiated in 1987, capturing 18 living individuals and using artificial insemination. This is one of the first examples of assisted reproduction contributing to conservation of an endangered species in nature.[29] The U.S. Fish & Wildlife Service (USFWS), state and tribal agencies, private landowners, conservation groups, and North American zoos, have actively reintroduced ferrets back into the wild since 1991. Beginning in Shirley Basin[30] in Eastern Wyoming, reintroduction expanded to Montana, 6 sites in South Dakota in 1994, Arizona, Utah, Colorado, Saskatchewan, Canada and Chihuahua, Mexico. The Toronto Zoo has bred hundreds, most of which were released into the wild.[31] Several episodes of Zoo Diaries show aspects of the tightly controlled breeding. In May 2000, the Canadian Species at Risk Act listed the black-footed ferret as being an extirpated species in Canada.[32] A population of 35 animals was released into Grasslands National Park in southern Saskatchewan on October 2, 2009,[33] and a litter of newborn kits was observed in July 2010.[34] Reintroduction sites have experienced multiple years of reproduction from released individuals.

The black-footed ferret was first listed as endangered in 1967 under the Endangered Species Preservation Act, and was relisted on January 4, 1974, under the Endangered Species Act. In September 2006, South Dakota's ferret population was estimated to be around 420, with 250 (100 breeding adults consisting of 67 females and 33 males) in Eagle Butte, South Dakota which is 100,000 acres, less than 3 percent of the public grasslands in South Dakota, 70 miles East of Rapid City, South Dakota in the Buffalo Gap National Grassland bordering Badlands National Park, 130 ferrets northeast of Eagle Butte, SD on Cheyenne River Indian Reservation and about 40 ferrets on the Rosebud Indian Reservation.[35] Arizona's Aubrey Valley ferret population was well over 100 and a second reintroduction site with around 50 animals is used. An August 2007 report in the journal Science counted a population of 223 in one area of Wyoming (the original number of reintroduced ferrets, most of which died, was 228), and an annual growth rate of 35% from 2003–2006 was estimated.[36][37] This rate of recovery is much faster than for many endangered species, and the ferret seems to have prevailed over the previous problems of disease and prey shortage that hampered its improvement.[37] As of 2007, the total wild population of black-footed ferrets in the U.S. was well over 650 individuals, plus 250 in captivity. In 2008, the IUCN reclassified the species as "globally endangered", a substantial improvement since the 1996-assessment, when it was considered extinct in the wild, as the species was indeed only surviving in captivity.

As of 2013, about 1,200 ferrets are thought to live in the wild.[38]

Conservation efforts have been opposed by stock growers / ranchers, who have traditionally fought prairie dogs. In 2005, the U.S. Forest Service began poisoning prairie dogs in private land buffer zones of the Conata Basin of Buffalo Gap National Grassland, SD. Because 10–15 ranchers complained the measure was inadequate, the forest service advised by Mark Rey, then Undersecretary of Agriculture, expanded its "prairie-dog management" in September 2006 to all of South Dakota's Buffalo Gap and the Fort Pierre National Grassland, and also to the Oglala National Grassland in Nebraska, against opinions of biologists in the U.S. Fish and Wildlife Service. Following exposure by conservation groups including the Climate, Community & Biodiversity Alliance and national media[39] public outcry and a lawsuit mobilized federal officials, and the poisoning plan was revoked.

The contradictory mandates of the two federal agencies involved, the USFWS and the U.S. Forest Service are exemplified in what the Rosebud Sioux tribe experienced: The ferret was reintroduced by the USFWS, which according to the tribe promised to pay more than $1 million a year through 2010. On the other hand, the tribe was also contracted for the U.S. forest service prairie dog poisoning program. The increasing numbers of ferrets led to conflicts between the tribe's Cheyenne River Sioux Tribe Game, Fish and Parks Department and the Tribal Land Enterprise Organization. When the federal government started an investigation of the tribe's prairie dog management program, threatening to prosecute tribal employees or agents carrying out the management plan in the ferret reintroduction area, the tribal council passed a resolution in 2008, asking the two federal agencies to remove ferrets, and reimburse the tribe for its expenses for the ferret recovery program.[40]

See also



 This article incorporates public domain material from the United States Department of Agriculture document "Mustela nigripes".

  1. ^ a b Belant, J.; Gober, P. & Biggins, D. (2008). "Mustela nigripes". IUCN Red List of Threatened Species. Version 2008. International Union for Conservation of Nature. Retrieved March 21, 2009. Database entry includes a brief justification of why this species is of endangered.
  2. ^ a b Heptner, V. G. (Vladimir Georgievich); Nasimovich, A. A; Bannikov, Andrei Grigorevich; Hoffmann, Robert S. (2001). Mammals of the Soviet Union Volume: v. 2, pt. 1b. Washington, D.C. : Smithsonian Institution Libraries and National Science Foundation.
  3. ^ Coues 1877, p. 151
  4. ^ Black-footed Ferret Recovery Implementation Team. Retrieved on March 22, 2013.
  5. ^ McLendon, Russell (September 30, 2011). "Rare U.S. ferret marks 30-year comeback". Mother Nature Network. Retrieved October 9, 2011.
  6. ^ Belant, J.; Gober, P. & Biggins, D. (2008). "Mustela nigripes". IUCN Red List of Threatened Species. Version 2008. International Union for Conservation of Nature. Retrieved July 24, 2017. Database entry includes a history of Red List assessments.
  7. ^ a b c d e f g h Hillman, Conrad N.; Clark, Tim W. (1980). "Mustela nigripes". Mammalian Species. 126 (126): 1–3. doi:10.2307/3503892.
  8. ^ a b Merriam 1896, p. 8
  9. ^ a b c d e f g h i j k Houston, B. R.; Clark, Tim W.; Minta, S. C. (1986). "Habitat suitability index model for the black-footed ferret: a method to locate transplant sites". Great Basin Naturalist Memoirs. 8: 99–114.
  10. ^ a b c d e f g h i j k l m n o p q Richardson, Louise; Clark, Tim W.; Forrest, Steven C.; Campbell, Thomas M. (1987). "Winter ecology of black-footed ferrets (Mustela nigripes) at Meeteetse, Wyoming". The American Midland Naturalist. 117 (2): 225–239. doi:10.2307/2425964. JSTOR 2425964.
  11. ^ a b c d Clark, Tim W. (1986). "Some guidelines for management of the black-footed ferret". Great Basin Naturalist Memoirs. 8: 160–168.
  12. ^ a b c d e f g h i j k l m Hillman, Conrad N. 1968. Life history and ecology of the black-footed ferret in the wild. Brookings, SD: South Dakota State University. Thesis
  13. ^ a b Kurtén 1980, pp. 152–153
  14. ^ a b Owen, Pamela R.; Bell, Christopher J. (2000). "Fossils, diet, and conservation of black-footed ferrets (Mustela nigripes)". Journal of Mammalogy. 81 (2): 422. doi:10.1644/1545-1542(2000)081<0422:FDACOB>2.0.CO;2. JSTOR 1383400.
  15. ^ Audubon & Bachman 1851, p. 297
  16. ^ a b Coues 1877, pp. 147–148
  17. ^ a b Biggins, Dean E. and Max H. Schroeder. (1988). Historical and present status of the black-footed ferret. pp. 9397. In Eighth Great Plains Wildlife Damage Control Workshop, USDA Forest Service Gen. Tech. Rpt. RM-154, Rapid City, South Dakota.
  18. ^ Wisely, Samantha M.; Santymire, Rachel M.; Livieri, Travis M.; Marinari, Paul E.; Kreeger, Julie S.; Wildt, David E.; Howard, Jogayle (2005). "Environment influences morphology and development for in situ and ex situ populations of the black-footed ferret (Mustela nigripes)" (PDF). Animal Conservation. 8 (3): 321–328. doi:10.1017/S1367943005002283.
  19. ^ a b c d e f Clark, Tim W. (1976). "The black-footed ferret". Oryx. 13 (3): 275–280. doi:10.1017/S0030605300013727.
  20. ^ "Black-Footed Ferret (Mustela nigripes)". National Parks Conservation Association. Archived from the original on January 10, 2010. Retrieved June 14, 2010.
  21. ^ a b c d e f Clark, Tim W. (1987). "Restoring balance between the endangered black-footed ferret (Mustela nigripes) and human use of the Great Plains and Intermountain West" (PDF). Journal of the Washington Academy of Sciences. 77 (4): 168–173. Archived from the original (PDF) on June 6, 2013. Retrieved November 7, 2018.
  22. ^ a b c d e f g h i j k l m Forrest, Steven C.; Biggins, Dean E.; Richardson, Louise; Clark, Tim W.; Campbell, Thomas M., III; Fagerstone, Kathleen A.; Thorne, E. (1988). "Population attributes for the black-footed ferret (Mustela nigripes) at Meeteetse, Wyoming, 1981–1985". Journal of Mammalogy. 69 (2): 261–273. doi:10.2307/1381377. JSTOR 1381377.
  23. ^ a b c d e U.S. Fish and Wildlife Service. (1988). Species account: Black-footed ferret—Mustela nigripes, In: Endangered Species Program. Pierre, SD: U.S. Fish and Wildlife Service, Mountain-Prairie Region, South Dakota Ecological Services Field Office
  24. ^ Stromberg, Mark R.; Rayburn, R. Lee; Clark, Tim W. (1983). "Black-footed ferret prey requirements: an energy balance estimate". Journal of Wildlife Management. 47 (1): 67–73. doi:10.2307/3808053. JSTOR 3808053.
  25. ^ Canada, Parks Canada Agency, Government of. "index".
  26. ^ Williams, E.S.; D.R. Kwiatkowski; E.T. Thorne & A. Boerger-Fields (1994). "Plague in a black-footed ferret" (PDF). Journal of Wildlife Diseases. 30 (4): 581–5. doi:10.7589/0090-3558-30.4.581. PMID 7760495.
  27. ^ a b Audubon & Bachman 1851, pp. 298–299
  28. ^ Livieri T.M. (April 28, 2013). Assessing the risk of plague to black-footed ferrets in Conata Basin, South Dakota. Final Report to South Dakota Game, Fish & Parks, 2012 Wildlife Diversity Grant.
  29. ^ a b Wildt, David E.; Wemmer, Christen (July 1999). "Sex and wildlife: the role of reproductive science in conservation". Biodiversity and Conservation. 8 (7): 965–976. doi:10.1023/A:1008813532763.
  30. ^ Black-footed Ferret Recovery – A Timeline.
  31. ^ "Toronto Zoo > Conservation > Mammals". Retrieved 5 September 2015.
  32. ^ "Species at Risk – Black-footed Ferret". Environment Canada. May 8, 2006. Retrieved 5 September 2015.
  33. ^ "Black-footed ferret back on prairie turf". Parks Canada. October 2, 2009. Retrieved 5 September 2015.
  34. ^ "Black-footed ferrets breeding in Sask". CBC News. August 4, 2010. Retrieved August 5, 2010.
  35. ^ Harlan, Bill (September 24, 2006)."South Dakota a ferret focal point". Rapid City Journal.
  36. ^ Fox, Maggie (August 9, 2007). "Once rare black-footed ferrets make comeback". Reuters. Retrieved October 2, 2009.
  37. ^ a b Fountain, Henry (August 14, 2007). "Call It a Comeback: Ferret Population Shows Big Growth in Wyoming". The New York Times. The New York Times Company. Retrieved October 2, 2009.
  38. ^ Black footed Ferret in "Defenders", Fall 2013, page 22.
  39. ^ CNN Broken government series "Scorched Earth”. February 21, 2008
  40. ^ Rosebud tribe tells feds to remove ferrets. Aberdeen News, March 14, 2008


Further reading

External links

Badlands National Park

Badlands National Park (Lakota: Makȟóšiča) is an American national park located in southwestern South Dakota. The park protects 242,756 acres (379.3 sq mi; 982.4 km2) of sharply eroded buttes and pinnacles, along with the largest undisturbed mixed grass prairie in the United States. The National Park Service manages the park, with the South Unit being co-managed with the Oglala Lakota tribe.The Badlands Wilderness protects 64,144 acres (100.2 sq mi; 259.6 km2) of the park as a designated wilderness area, and is one site where the black-footed ferret, one of the most endangered mammals in the world, was reintroduced to the wild. The South Unit, or Stronghold District, includes sites of 1890s Ghost Dances, a former United States Air Force bomb and gunnery range, and Red Shirt Table, the park's highest point at 3,340 feet (1,020 m).Authorized as Badlands National Monument on March 4, 1929, it was not established until January 25, 1939. Badlands was redesignated a national park on November 10, 1978. Under the Mission 66 plan, the Ben Reifel Visitor Center was constructed for the monument in 1957–58. The park also administers the nearby Minuteman Missile National Historic Site. Movies such as Dances with Wolves (1990) and Thunderheart (1992) were partially filmed in Badlands National Park.

Buffalo Gap National Grassland

Buffalo Gap National Grassland is a National Grassland located primarily in southwestern South Dakota, United States. It is also the second largest National Grassland, after Little Missouri National Grassland in North Dakota. Characteristics of the grasslands include mixed prairie and chalky badlands. The grassland is managed by the U.S. Forest Service and is a division of Nebraska National Forest. In descending order of land area it is located in parts of Fall River, Pennington, Jackson, and Custer counties.

Buffalo Gap National Grassland is managed by the Forest Service together with the Nebraska and Samuel R. McKelvie National Forests and the Fort Pierre and Oglala National Grasslands from common offices in Chadron, Nebraska. There are local ranger district offices located in Hot Springs and Wall. It also surrounds Badlands National Park and Minuteman Missile National Historic Site.

In what is known as the Conata Basin region of the grassland, the most successful Black-footed ferret reintroduction program undertaken by the federal government, has established a small but sustainable population of these previously extirpated mammals.

In 2010, South Dakota Senator Tim Johnson introduced the Tony Dean Cheyenne River Valley Conservation Act of 2010, a bill that would designate over 48,000 acres (19,000 ha) of the National Grassland as protected wilderness. The act would allow the continuation of grazing and hunting on the land and would create the first national grassland wilderness in the country.In Jan. 2013, Charmaine White Face raised concerns about radiation exposure of South Dakota Army National Guard soldiers in the Buffalo Gap National Grassland.

Conservation-induced extinction

Efforts to save endangered species may, paradoxically, lead to conservation-induced extinction of other species. This mostly threatens the parasite and pathogen species that are highly host-specific to critically endangered hosts. When the last individuals of a host species are captured for the purpose of captive breeding and reintroduction programs, they typically undergo anti-parasitic treatments to increase survival and reproductive success. This practice may unintentionally result in the extinction of the species antagonistic to the target species, such as certain parasites. It has been proposed that the parasites should be reintroduced to the endangered population. A few cases of conservation-induced extinction have occurred in parasitic lice.

Detection dog

A detection dog or sniffer dog is a dog that is trained to use its senses to detect substances such as explosives, illegal drugs, wildlife scat, currency, blood, and contraband electronics such as illicit mobile phones. The sense most used by detection dogs is smell. Hunting dogs that search for game, and search dogs that work to find missing humans are generally not considered detection dogs. There is some overlap, as in the case of cadaver dogs, trained to search for human remains. A police dog is essentially a detection dog that is used as a resource for police in specific scenarios such as conducting drug raids, finding missing criminals, and locating stashed currency.

Frequently, detection dogs are thought to be used for law enforcement purposes; however, they are also used as a valuable research tool for wildlife biologists. In California, detection dogs are trained to discover quagga mussels on boats at public boat ramps because they are a harmful invasive species for the environment. Detection dogs also tend to be employed for the purposes of finding and collecting the feces of a diverse array of species, including caribou, black-footed ferret, killer whale, and Oregon spotted frog. This process is known as wildlife scat detection.

Detection dogs are also seeing use in the medical industry, as studies have revealed that canines are able to detect specific odours associated with numerous medical conditions, such as cancer.

European polecat

The European polecat (Mustela putorius) – also known as the common ferret, black or forest polecat, or fitch (as well as some other names) – is a species of mustelid native to western Eurasia and north Morocco. It is of a generally dark brown colour, with a pale underbelly and a dark mask across the face. Occasionally, colour mutations, including albinos and erythrists, occur. Compared to minks and other weasels – fellow members of the genus Mustela – the polecat has a shorter, more compact body; a more powerfully built skull and dentition; is less agile; and it is well known for having the characteristic ability to secrete a particularly foul-smelling liquid to mark its territory.

It is much less territorial than other mustelids, with animals of the same sex frequently sharing home ranges. Like other mustelids, the European polecat is polygamous, though pregnancy occurs directly after mating, with no induced ovulation. It usually gives birth in early summer to litters consisting of five to 10 kits, which become independent at the age of two to three months. The European polecat feeds on small rodents, birds, amphibians and reptiles. It occasionally cripples its prey by piercing its brain with its teeth and stores it, still living, in its burrow for future consumption.The European polecat originated in Western Europe during the Middle Pleistocene, with its closest living relatives being the steppe polecat, the black-footed ferret and the European mink. With the two former species, it can produce fertile offspring, though hybrids between it and the latter species tend to be sterile, and are distinguished from their parent species by their larger size and more valuable pelts.The European polecat is the sole ancestor of the ferret, which was domesticated more than 2000 years ago for the purpose of hunting vermin. The species has otherwise been historically viewed negatively by humans. In the British Isles especially, the polecat was persecuted by gamekeepers, and became synonymous with promiscuity in early English literature. During modern times, the polecat is still scantly represented in popular culture when compared to other rare British mammals, and misunderstandings of its behaviour still persist in some rural areas. As of 2008, it is classed by the IUCN as Least Concern due to its wide range and large numbers.


The ferret (Mustela putorius furo) is the domesticated form of the European polecat, a mammal belonging to the same genus as the weasel, Mustela, in the family Mustelidae. Their fur is typically brown, black, white, or mixed. They have an average length of 51 cm (20 in), including a 13 cm (5.1 in) tail, weigh about 1.5–4 pounds (0.7–2 kg), and have a natural lifespan of 7 to 10 years. Ferrets are sexually dimorphic predators, with males being substantially larger than females.

The history of the ferret's domestication is uncertain, like that of most other domestic animals, but it is likely that they have been domesticated for at least 2,500 years. They are still used for hunting rabbits in some parts of the world, but increasingly they are kept only as pets.

Being so closely related to polecats, ferrets easily hybridize with them, and this has occasionally resulted in feral colonies of polecat–ferret hybrids that have caused damage to native fauna, especially in New Zealand. As a result, New Zealand and some other parts of the world have imposed restrictions on the keeping of ferrets.

Several other mustelids also have the word ferret in their common names, including the black-footed ferret, an endangered species.

Ferret (disambiguation)

A ferret is a domesticated animal. Ferret may also refer to:

Other AnimalsThe Black-footed ferret, a wild animal from North AmericaComputingFerret Data Visualization and Analysis, an interactive visualization and analysis meteorology software.MilitaryThe Ferret armoured car, a British-produced fighting vehicle.

HMS Ferret, the name of a number of ships and shore establishments of the Royal Navy

Fairey Ferret, a British biplane

Ferret is another name for Electronic signals intelligence-gathering aircraft.MusicFerret Music, a record label

The Ferrets (band), an Australian pop/rock band

Pierre Ferret (1908–1978), a Gypsy jazz guitarist and composerPlacesVal Ferret, a valley on the Swiss side of the Mont Blanc Massif

Cap Ferret, a headland on France's Atlantic coastOtherFerret game or Button, button, who's got the button?

The Ferret, a consumer affairs television programme on HTV Wales

The Ferret (news), a media cooperative in Scotland

Ferret (comics), a Timely Comics character from the Golden Age of Comic Books.

Bait in fishing

JoGayle Howard

JoGayle Howard (1951–2011) was an American zoologist specializing in the captive breeding of endangered species such as pandas, clouded leopards and black-footed ferrets.

Meeteetse, Wyoming

Meeteetse is a town in Park County, Wyoming, United States. The population was 327 at the 2010 census.


The Mustelidae (; from Latin mustela, weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, mink, and wolverines, among others. Mustelids are diverse and the largest family in the order Carnivora, suborder Caniformia. Mustelidae comprises about 56-60 species across eight subfamilies.


Mustelinae is a subfamily of family Mustelidae, which includes weasels, ferrets amd minks.It was formerly defined in a paraphyletic manner to also include wolverines, martens, and many other mustelids, to the exclusion of the otters (Lutrinae).


Polecat is a common name for mammals in the order Carnivora and subfamilies Galictinae and Mustelinae. Polecats do not form a single taxonomic rank (i.e., clade); the name is applied to several species with broad similarities (including having a dark mask-like marking across the face) to European polecats, the only species native to the British Isles.

In the United States, the term polecat is sometimes applied to the black-footed ferret, a native member of the Mustelinae, and (loosely) to skunks, which are only distantly related.

Despite the name, polecats, being various caniform mustelids, are more closely related to dogs than cats, which is why they belong to the suborder Caniformia.

In Canada, the term polecat is sometimes applied to electric utility linemen.

Prairie Learning Centre

The Prairie Learning Centre (PLC) is an educational centre located near Grasslands National Park, Saskatchewan, that hosts curriculum linked workshops on the native prairie landscape. With the support of Grasslands National Park, Chinook School Division and the Village of Val Marie, Saskatchewan, the Prairie Learning Centre provides innovative learning opportunities for secondary school students. The PLC aims to promote stewardship of the mixed grass prairie ecosystem.

Workshops linked to the grade 9-12 curriculum are available throughout the year. Program topics range from prairie ecology to First Nations storytelling. All programs take place on the native prairie of Grasslands National Park. Biologists, wildlife specialists, and First Nations storytellers are facilitators that enhance these workshops. Students have the opportunity to monitor the threatened burrowing owl, watch a herd of plains bison, or discover a dinosaur fossil. Students also have the opportunity to learn about astronomy at the Grasslands National Park dark-sky preserve.

Grasslands National Park is one of the last remaining sections of mixed-grass prairie in Canada. It is home to the greater short-horned lizard (Saskatchewan's only lizard species), the black-footed ferret (the most endangered mammal in North America) and pronghorn (the second fastest land mammal in the world). The Committee on the Status of Endangered Wildlife in Canada have listed over 15 species found in the park as at risk.

Sylvatic plague

Sylvatic plague is an infectious bacterial disease caused by the bacterium Yersinia pestis that primarily affects rodents such as prairie dogs. It is the same bacterium that causes bubonic and pneumonic plague in humans. Sylvatic, or sylvan, means 'occurring in wildlife,' and refers specifically to the form of plague in rural wildlife. Urban plague refers to the form in urban wildlife.

It is primarily transmitted among wildlife through flea bites and contact with infected tissue or fluids. Sylvatic plague is most commonly found in prairie dog colonies and some mustelids like the black-footed ferret.

UL Bend National Wildlife Refuge

UL Bend National Wildlife Refuge is a 56,048 acres (22,682 ha) protected area that is located in central Montana, United States. The refuge, located at the extreme southernmost tip of Phillips County, is managed and bordered on three sides by the Charles M. Russell National Wildlife Refuge and the Fort Peck Reservoir on the Missouri River. The UL Bend Wilderness comprises almost half the refuge and provides a high level of protection to the most remote regions. This refuge is remote, requiring travel by gravel and dirt roads that can be difficult to navigate during inclement weather. A large species population of red fox, bald eagle, bighorn sheep, golden eagle, black bear, great horned owl, moose, burrowing owl, coyote, elk, swift fox, bobcat, pronghorn, mule deer, and cougar inhabit this refuge. Prairie dogs are abundant and are the primary food source for the black-footed ferret, which is listed as an endangered species. The Black-footed ferret has been reintroduced into the refuge after nearing extinction yet the sustainability of this relocated species is not yet known, and there are only 1,000 remaining in breeding compounds and perhaps 100 in the wild. Researchers in 2002 were only able to locate a total of 5 ferrets in the entire refuge.

UL Bend Wilderness is a 20,819-acre (8,425 ha) wilderness area within the refuge that was established in 1976 to provide a higher level of protection to the more remote sections. The refuge is managed by the U.S. Fish and Wildlife Service, an agency of the U.S. Department of the Interior. The refuge is an integral part of the Charles M. Russell National Wildlife Refuge Complex.

UL Bend Wilderness

The UL Bend Wilderness comprises 20,819 acres (84 km2) and is located in the U.S. state of Montana within the UL Bend National Wildlife Refuge, which in turn is also completely surrounded by the Charles M. Russell National Wildlife Refuge. Bordering on the Fort Peck Reservoir, a portion of the Missouri River that has been damed. There are no maintained trails and the only access is either on foot or horseback. The Upper Missouri Breaks National Monument is located immediately west of the wilderness. The Lewis and Clark Expedition passed through this region and wrote extensively on the abundance of wildlife and the ruggedness of the countryside.

U.S. Wilderness Areas do not allow motorized or mechanized vehicles, including bicycles. Although camping and fishing are allowed with proper permit, no roads or buildings are constructed and there is also no logging or mining, in compliance with the 1964 Wilderness Act. Wilderness areas within National Forests and Bureau of Land Management areas also allow hunting in season. Hunting is permitted in this wilderness.

Broken into three sections, the largest portion is characterized by steep sided cliffs of the Missouri River "Breaks" country. Along the riverbanks, cottonwood trees flourish and are home to a wide diversity of wildlife. Mammals such as elk, bighorn sheep, pronghorn, bobcats and badgers thrive here and numerous waterfowl such as pelicans, canada geese and herons are also common.

In the 1990s, UL Bend Wilderness was one of several sites selected for reintroduction of a small number of black-footed ferrets, the most endangered mammal in North America. The carnivorous black-footed ferret is heavily dependent on a plentiful supply of prairie dogs as this constitutes the bulk of their food intake.


Yubaatar is a genus of multituberculate, an extinct order of rodent-like mammals, which lived in what is now China during the Late Cretaceous. The first specimen was discovered in the Qiupa Formation of Luanchuan County, in the Henan Province. The specimen consists of a partial skeleton with a nearly complete skull, and was made the holotype of the new genus and species Yubaartar zhongyuanensis by the Chinese palaeontologist Li Xu and colleagues in 2015. The generic name consists of the word Yu, which is the pinyin spelling of the Chinese character for the Henan Province, and the Mongolian word baatar, which means "hero", a word commonly used as suffix in the names of Asian multituberculates. The specific name comes from Zhongyuan, an ancient name for the geographic area of the province.

Yubaatar is the first known and southernmost Late Cretaceous multituberculate outside of the Mongolian plateau (most multituberculate specimens mainly consist only of teeth and jaws, and are rarely found in eastern Asia). With a skull 7 cm long, Yubaatar is estimated to have been the size of a black-footed ferret, and was the largest member of the group known from Eurasia (larger members are known from North America). Sphenopsalis was similar in size, but most other Mesozoic multituberculates were the size of a shrew or rat. Yubaatar had a unique feature among multituberculates in that its last upper premolar was replaced. The holotype specimen had a palaeopathology unique among known Mesozoic mammal, a severely broken right tibia bone, which was probably damaged in an accident, but had healed.Yubaatar was found to be basal to the clade Taeniolabidoidea, which consists of North American and Asian multituberculates; this indicates there was a faunal interchange between Asia and North America before the Cretaceous–Paleogene transition. The morphology of Yubaatar indicates that diversity in the complexity of the teeth of mutituberculates, relating to their diets, increased with the number of genera and difference in body size, and that there wa sa shift in adaptations towards increased herbivory in the group across the Cretaceous–Paleogene boundary.


Zodiolestes is a genus of mustelids, now extinct, which existed during the Miocene period.

The genus was first described in 1942, by E. S. Riggs, who identified the sister genus Promartes at the same time, and assigned to the family Procyonidae. In 1998 it was assigned to the subfamily Oligobuninae of the family Mustelidae. Two species have been identified in the genus: Z. daimonelixensis and Z. freundi.Z. daimonelixensis showed digging adaptations, as one fossil was found curled up in the "corkscrew" burrow of the Miocene beaver, Palaeocastor. Zodiolestes was most likely a predator of these fossorial beavers. This situation was analogous to the modern day prairie dogs (Cynomys ludovicianus) and its predator the black-footed ferret (Mustela nigripes).


ZooAmerica is a zoo located in Hershey, Pennsylvania, United States. The zoo was founded in 1910 by Milton S. Hershey with a few animals, including bears, birds, and deer. Today, the zoo covers 11 acres and is home to more than 75 species and 200 individual animals, including some that are rare and endangered.The zoo is privately controlled by the Hershey Trust Company and is connected to Hershey Park. ZooAmerica is also an accredited member of the Association of Zoos and Aquariums (AZA) and the World Association of Zoos and Aquariums (WAZA).

Extant Carnivora species

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