The mink (Mustela vison) is a member of the weasel family, which also includes skunks, otters, and wolverines. Mink are perhaps best know for their dark brown fur, which turns white at the chin and runs to black at the tips of their tails. They have long, slender torsos atop short legs. Full-grown females are usually 17 to 21 inches long and weigh 1.25 to 1.75 pounds, while full-grown males are usually 21 to 24 inches in length and weigh 2 to 3.75 pounds.
Mink are found along rivers, streams, lakes, ponds, and marshes throughout North America, northern Europe, and the former Soviet Union. They travel well on both land and water, able to swim as deep as 15-20 feet under water on one breath. They particularly like habitats that provide good cover—such as grass, brush, trees, and aquatic vegetation—and abundant food sources. Mink den in cavities in brush or rock piles, logjams, exposed roots of trees, and abandoned muskrat burrows.
They are nocturnal animals, active from dusk to dawn. Although mink do not hibernate during the winter, they will sometimes stay in their dens for a day or so during snowy or cold periods. Scientists have noticed that their activity levels seem to increase before storms and changes in weather.
Except when raising their young, adult mink are loners. Females start breeding at 10 to 12 months of age, mating usually between February and April, depending on climate. Since both males and females may mate with multiple partners, kits in the same litter may have different fathers. After about 50 days of gestation, females give birth to a single litter of about four kits. Born blind, hairless, and about 3.5 inches long, these kits will learn to hunt by 6 or 8 weeks but will remain with their mother until their first autumn.
Mink's lives are relatively short, about three years. Their chief predators are owls, coyotes, and cats—and, of course, man. Their primarily prey are rodents, frogs, mice, rats, rabbits, fish, crayfish, birds, squirrels, waterfowl eggs, and muskrats. Like all weasels, mink are fierce fighters, capable of attacking prey much larger than themselves.
There are fewer mink in the wild than there were 50 years ago. The quality of their habitat has been degraded through development, the breaking up of streams and river for irrigation, and navigation, and the drainage of wetlands. Trapping for fur has also decreased wild mink populations, and although the fur industry has increasingly turned to breeding minks, it continues to diminish wild populations.
If you would like to learn more about mink, read this in-depth study from The American Society of Mammologists.
