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Wellington, CO, United States

Eads D.A.,Colorado State University | Biggins D.E.,U.S. Geological Survey | Livieri T.M.,Prairie Wildlife Research | Millspaugh J.J.,University of Missouri
Journal of Mammalogy | Year: 2013

We evaluated how American badgers (Taxidea taxus) might exert selective pressure on black-footed ferrets (Mustela nigripes) to develop antipredator defenses. In a colony of black-tailed prairie dogs (Cynomys ludovicianus) in South Dakota, badgers concentrated their activities where burrow openings and prairie dogs were abundant, a selective behavior that was exhibited by ferrets in the same colony. Badgers excavated burrows more often when in areas recently used by a ferret, suggesting that badgers hunt ferrets or steal prey from ferrets, or both. We also conducted an analysis of survival studies for ferrets and Siberian polecats (M. eversmanii) released onto prairie dog colonies. This polecat is the ferret's ecological equivalent but evolved without a digging predator. Badgers accounted for 30.0% of predation on polecats and 5.5% of predation on ferrets. In contrast, both polecats and ferrets have evolutionary experience with canids, providing a plausible explanation for the similar relative impact of coyotes (Canis latrans) on them (65.0% and 67.1% of predation, respectively). We hypothesize that ferrets and badgers coexist because ferrets are superior at exploitation competition and are efficient at avoiding badgers, and badgers are superior at interference competition. © 2013 American Society of Mammalogists. Source

Eads D.A.,U.S. Geological Survey | Biggins D.E.,U.S. Geological Survey | Livieri T.M.,Prairie Wildlife Research
Journal of Zoology | Year: 2015

In western North America, endangered black-footed ferrets Mustela nigripes are conserved via reintroduction to colonies of prairie dogs Cynomys spp., their primary prey. Predation is an important source of mortality; coyotes Canis latrans appear to be the most problematic predator, accounting for 67% of known predation events on radio-tagged ferrets. Little is known about what factors affect spatial use of prairie dog colonies by coyotes, or how other animals might affect interactions between coyotes and ferrets. During June-October 2007-2008, we used spotlight surveys to monitor coyotes and ferrets (both years) and rabbits Sylvilagus spp. (first year) on a 452-ha colony of black-tailed prairie dogs Cynomys ludovicianus in the Conata Basin, South Dakota. Coyotes appeared to select areas of the colony used by rabbits, suggesting coyotes hunted rabbits, a common item in their diet. Between midnight and sunrise, ferrets were most commonly observed during early morning (01:00-03:00h), whereas coyotes were observed mostly during dawn (04:00h - sunrise) when ferrets were rarely seen. These temporal differences in the timing of observations suggest ferrets tend to remain underground in burrows when coyotes are most active. Coyotes appeared to be attracted to rabbits in both space and time, suggesting the risk of predation for ferrets might relate to the abundance and locations of rabbits in prairie dog colonies. © 2015 The Zoological Society of London. Source

Cain C.M.,Central Michigan University | Livieri T.M.,Prairie Wildlife Research | Swanson B.J.,Central Michigan University
Journal of Mammalogy | Year: 2011

The black-footed ferret (Mustela nigripes) went extinct in the wild when the last 18 known ferrets were captured for a captive-breeding program. Following the success of the captive-breeding program, 146 genetically nonessential ferrets were released at the Conata Basin, South Dakota, from 1996 to 1999. We conducted a genetic analysis of the Conata Basin black-footed ferret population from 2001 to 2003 to determine if genetic variation had been lost since the cessation of reintroductions and if demographic- and genetic-based estimates of effective population size (Ne) accurately predicted observed levels of heterozygosity. We used DNA from wild-born kits (n ?=? 254) in the Conata Basin population (20012003) to calculate current genetic diversity levels. Both allelic diversity (A ?=? 2, both subpopulations) and mean heterozygosity were low for both subpopulations0.39 ± 0.12 SE in Agate-Sage Creek and 0.39 ± 0.16 SE in Heck Tablebut not significantly different from estimates made in 1999. We found no significant difference between observed and expected heterozygosity levels. Demographic-based estimates of Ne were an order of magnitude higher than genetic-based estimates of Ne, but the 2 estimates provide a range of Ne values for the population. This study shows that the Conata Basin ferret population is able to maintain its genetic diversity over time despite its population history. © 2011 American Society of Mammalogists. Source

Eads D.A.,University of Missouri | Millspaugh J.J.,University of Missouri | Biggins D.E.,U.S. Geological Survey | Livieri T.M.,Prairie Wildlife Research | Jachowski D.S.,University of Missouri
Journal of Mammalogy | Year: 2011

We investigated postbreeding resource selection by adult black-footed ferrets (Mustela nigripes) on a 452-ha black-tailed prairie dog (Cynomys ludovicianus) colony in the Conata Basin of South Dakota during 20072008. We used resource selection functions (RSFs) to evaluate relationships between numbers of ferret locations and numbers of prairie dog burrow openings (total or active), distances to colony edges, and connectivity of patches of burrow openings. In both years ferrets selected areas near edges of the prairie dog colony where active burrow openings were abundant. In the interior of the colony ferrets selected areas with low abundance of active burrow openings. At times, prairie dog productivity (i.e., pup abundance) might be greatest at colony edges often characterized by grasses; ferrets are likely to select areas where refuge and vulnerable prey are abundant. Ferrets could have used interior areas with few active burrow openings as corridors between edge areas with many active burrow openings. Also, in areas with few active burrow openings ferrets spend more time aboveground during movements and, thus, are likely to be more easily detected. These results complement previous studies demonstrating importance of refuge and prey in fine-scale resource selection by ferrets and provide insight into factors that might influence edge effects on ferret space use. Conservation and restoration of colonies with areas with high densities of burrow openings and prairie dogs, and corridors between such areas, are needed for continued recovery of the black-footed ferret. RSFs could complement coarse-scale habitat evaluations by providing finer-scale assessments of habitat for the black-footed ferret. © 2011 American Society of Mammalogists. Source

Biggins D.E.,U.S. Geological Survey | Livieri T.M.,Prairie Wildlife Research | Breck S.W.,Wildlife ServicesNational Wildlife Research Center
Journal of Mammalogy | Year: 2011

Questions and problems that emerged during operational conservation of black-footed ferrets (Mustela nigripes) have been addressed by a wide variety of studies. Early results from such studies often were communicated orally during meetings of recovery groups and in written form using memoranda, unpublished reports, and theses. Typically, implementation of results preceded their publication in widely distributed journals. Many of these studies eventually were published in journals, and we briefly summarize the contents of 8 volumes and special features of journals that have been dedicated to the biology of ferrets and issues in ferret recovery. This year marks the 30th anniversary of rediscovery of the black-footed ferret, and the 7 papers of the following Special Feature summarize data collected over nearly that span of time. © 2011 American Society of Mammalogists. Source

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