The mink ( Mustela vison) is a semi-aquatic member of the weasel family that occurs throughout Kansas. Minks are excellent swimmers and primarily occupy habitat surrounding rivers, streams, wetlands, ponds, and lakes. They are most scarce in western Kansas where water courses are lacking. Even so, they are not entirely dependent upon a water source, and spend a good deal of time foraging or traveling in wooded or brushy upland sites. Home ranges vary considerably, but may include up to several miles of linear habitat along a water course.
Long and slender with short legs and bushy tail, the mink’s build is not unlike that of its closest relatives and two of our most obscure furbearers in Kansas, the least and long-tailed weasels. Minks have silky, chestnut-colored pelage and weigh two to three pounds, with males being slightly larger than females. Like other members of the weasel family, minks have highly developed anal glands. They are less proficient than skunks at emitting musk, though some consider minks’ scent even more unpleasant.
Like the other mustelids, minks are usually solitary, except during breeding season in February and March. Usually three or four but occasionally as many as eight kits are born around April. Den sites are usually abandoned beaver or muskrat bank burrows, or crevices in rock or brush piles, hollow logs, or abandoned beaver lodges.
Minks are highly carnivorous and prey upon a wide variety of both aquatic and terrestrial animals. They are tenacious predators and sometimes kill animals as large or larger than themselves. The bulk of their diet usually consists of mammals, with muskrats and mice topping the list. Other prey items include terrestrial rodents, rabbits, crayfish, water beetles, and other insects, fish, and frogs. Minks are also notorious nest predators, especially of waterfowl and domestic chickens. Because they readily cache food, they are prone to killing more than they can eat, especially when their quarry is confined – like in a hen house.
Few minks live longer than three years in the wild. They are sometimes eaten by great horned owls, coyotes, bobcats, or foxes, but the full impact of predation is unknown. Intraspecific aggression (one mink killing another) may be an important source of mortality. Unlike most furbearer species, minks are not significantly affected by diseases, but they may be susceptible to environmental contaminants such as mercury or pesticides.
Minks were among the most economically important Kansas furbearers until about 1970. At that time, long-haired furbearers became more popular garment items, and surpassed the traditional mink and muskrat markets. Currently, harvest levels and pelt prices are low in Kansas, and the mink is of minor importance to our fur trade. About 400 minks per year are harvested in Kansas, almost exclusively by trapping.