The mink is a mammal in the family Mustelidae, closely related to the weasel.
The term "mink" refers to any of several dark-colored, semi-aquatic, carnivorous mustelids in various subgenera of genus Mustela. The name may have originated in the Swedish maenk applied to the European animal. Captain John Smith, in his History of Virginia (1626), at p. 27 speaks of “Martins, Powlecats, Weesels and Minkes” referring to the American mink and showing that the term had already been incorporated into the English language by that time. By later authors, as Lawson (1709) and Pennant (1784), it is often written “Minx.”
The two best-known extant species are the European mink (Mustela lutreola), sometimes known as the marsh-otter, and the American mink (Mustela vison). Another form, Mustela sibirica from eastern Asia, is occasionally referred to as the "Siberian mink" but others would call it a "Siberian polecat." It is closely related to the European mink. Since "mink" is not a scientific term the question of whether to include it as a mink, a polecat or both is largely one of semantics.
The European mink inhabits Finland, Poland and the greater part of Russia, though not found east of the Ural Mountains. Formerly it extended westward into central Germany, but it is now extinct in that country. The American mink is found in places which suit its habits throughout almost the whole of North America, from Florida to the Arctic. An endangered subspecies, the Everglades mink (Mustela vison evergladensis), is endemic to the Florida Everglades. American mink of other subspecies have found their way into the wild in Europe (including Great Britain) and South America, as escapees from fur farms, and are currently expanding their range on those continents. In some areas of Russia deliberate introduction of this species has also occurred to provide quarry for fur trappers. The result has been disastrous for the European mink, who occupies almost the same ecological niche but is outcompeted by the larger and better-swimming American mink. Attempts are now underway to introduce the European mink to islands too far from the continent for American mink to swim to, in an attempt to prevent the species from becoming extinct.
The following description, chiefly of the American species but almost equally applicable to that of Europe, is from Dr Elliott Coues’s Fur-bearing Animals of North America, 1877. "In size it much resembles the English polecat—the length of the head and body being usually from 15 to 18 inches, that of the tail to the end of the hair about 9 inches. The female is considerably smaller than the male. The tail is bushy, but tapering at the end. The ears are small, low, rounded, and scarcely project beyond the adjacent fur. The pelage consists of a dense, soft, matted under-fur, mixed with long, stiff, lustrous hairs on all parts of the body and tail. The gloss is greatest on the upper parts; on the tail the bristly hairs predominate. Northern specimens have the finest and most glistening pelage; in those from southern regions there is less difference between the under- and over- fur, and the whole pelage is coarser and harsher. In colour different specimens present a considerable range of variation, but the animal is ordinarily of a rich dark brown." The coat can be almost black or black, and tends to be darker and thicker in the winter. To compensate for the fact that the animal has little subcutaneous fat, this fur traps air bubbles that keep it warm during its frequent dives into often-frigid water to search for prey.
It is sometimes possible to distinguish one species from the other based on the fact that the American mink usually lacks a large white patch on its upper lip, while the European mink always possesses one. Any mink without such a patch can be identified with certainty as an American mink, but an individual with such a patch, if encountered in continental Europe, cannot be identified for sure without looking at the skeleton. The European mink always and the American mink usually has a white spot on the lower lip, which continues in broken or unbroken fashion to form ventral markings. Since each is a different shape, it is possible to recognize individuals based on these ventral patterns. Fur also grows white over a scar and older mink tend to have more such patches, although absolute age is difficult to quantify without studying the animal from birth. In fur farms, mink are generally slaughtered after eight months, but can live several years in the wild (although mortality is high, especially among dispersing juveniles).
Occasionally in Europe American mink of other colors, such as Silverblu (greyish) and Sapphire (basically, blonde) can be seen. These mink inherited two copies of recessive coat color genes that are found at low frequencies in the wild, presumably because mink with these colors are less well-camouflaged. They are descendants, likely recent, of animals bred in fur farms specifically for these colors. (See Mendelian genetics for detailed information on principles of inheritance.) Other animals that have been bred by humans for coat color variety include the domestic cat (Felis silvestris catus, whose wild ancestors were muted, blotched tabbies) and the domestic ferret.
Female European mink are roughly 1.3 lbs. and males roughly 2 lbs; female American mink are roughly 2 lbs. and male American mink roughly 3.5 lbs., although weight can considerably vary and also depends on the quality of the environment. In general, since male American mink continue to grow into the winter but females do not, sexual dimorphism is lower in that species as environmental conditions become more hostile.
Mink fur has been highly prized for its use in clothing, with hunting giving way to large-scale mink farming. It has also been a focus of much animal rights protesting.
