Great Basin Naturalist Memoirs


Extensive literature review and 48 mammal collections containing recent speciments of the endangered black-footed ferret (Musela nigripes) are used to characterize historic distribution of species. Specimens (n = 120) were measured from eight collections to characterize black-footed ferret morphology and variation. Twenty-one pleistocene and Holocene faunas in North America show ferrets dating back to 100,000 yr B.P. Recent specimens (n = 412) indicate close association with the prairie dog (Cynomys spp.) and suggest ferrets may have been less rare than previously thought. At least 103 (25%) of all specimens were taken by federal predator and rodent control agents, and males outnumber females in collections 2.04:1. Average and extreme measurement for external, cranial, and postcranial dimensions are tabulated. Ferrets show a high degree of sexual dimorphism, with discriminant analysis correctly classifying 95% of all specimens to sex. Ferrets also exhibit north-south clinal variation in size, but they do not appear to exhibit variation based on species of Cynomys associate. The taxonimic relationship among ferrets and close relatives is described.