Mustela putorius furo is a member of the Mustelidae, order Carnivora [1,3,4]. Mustelidae originated forty million years ago in the Eocene period and includes ferrets, weasels, badgers, skunks, otters, minks, stoats, martens, and polecats [1,3]. Currently, there are sixty-seven species of mustelids distributed globally, inhabiting North, Central, and South America, Eurasia, and Africa [3,4]. All members exhibit relatively primitive carnivoran characteristics including small body size, short, stocky limbs, and five toes per foot [1,3].

Mustelidae contains six subfamilies [1,4]. Ferrets are included in the subfamily Mustelinae, along with martens, weasels, mink, and polecats [1,3,4]. Mustelinae originated in Eurasia, and its members currently inhabit northern regions [1,2]. Ferrets, polecats, weasels, and mink are included in the genus Mustela, and ferrets and polecats are in the subgenus Putorius [1,3,4]. Putorius includes three species: M. putorius (the European polecat), M. eversmanni (the steppe polecat), and M. nigripes (black-footed ferret) [1,3,4]. The domestic ferret, M. putorius furo, is considered to be a subspecies of the European polecat [1,2,3,4]. The European polecat originated in Europe in the Villafranchian era (three to four million years ago) [1].

Mustela putorius furo is generally considered to have been domesticated from polecats (M. putorius and M. eversmanni) over two thousand years ago for the purpose of controlling rodent and rabbit populations [1,3,4]. Currently, they are housed throughout the world as pets with approximately one million held in captivity in the United States [3,4]. Wild European polecats now inhabit open forests and meadows throughout Europe [4]. They are solitary and live in dens created by other animals as well as hollow logs and crevices [4]. Their home ranges are usually 100-150 ha [4]. The European polecat is a nocturnal, terrestrial carnivore that feeds on small birds, mammals, frogs, fish, and invertebrates [4]. Polecats and ferrets can kill small prey such as rats by severing the spinal cord with their teeth [3].

Wild European polecats and domestic ferrets are similar in size, shown in Table 1. A difference in coloration is seen between the two species. The European polecat is dark brown to black, with pale yellow underfur, while the domestic ferret is usually white or light tan with some black markings [3,4]. Domestic ferrets and the European polecats are genetically similar enough that they are able to interbreed, causing concern about the genetic integrity of wild populations [2,3,4]. Wild M. putorius typically live for five to six years, while the life span of captive ferrets can be as long as fourteen years [3,4]. European polecats mate once a year between March and June [3,4]. Domestic ferrets, on the other hand, can have two to three litters per year [3,4]. The gestation period for both species is forty-two days [3,4]. There can be up to seventeen pups in a litter, but most litters are of three to seven pups [3,4].

Table 1: Body size for male and female wild European polecats and domestic ferrets

Adapted from Nowak 1999.

References

1. Anderson, E. 1989. The phylogeny of mustelids and the systematics of ferrets. Pp. 10-20 in Conservation Biology and the Black-Footed Ferret. U.S. Seal, ed. Yale University Press, New Haven.

2. Davison, A., J.D.S. Birks, H.I. Griffiths, A.C. Kitchener, D. Biggins, and R.K. Butlin. 1999. Hybridization and the phylogenetic relationship between polecats and domestic ferrets in Britain. Biological Conservation 87: 155-161.

3. Fox, J.G. 1998. Biology and Diseases of the Ferret (2nd Ed.). Williams & Wilkins, Baltimore.

4. Nowak, R.M. 1999. Walker's Mammals of the World (Vol. 1) (6th Ed.). Johns Hopkins University Press, Baltimore.