Eastern mink, New World mink, North American mink
The American mink The American mink (Neogale vison) is a semiaquatic species of mustelid native to North America. It is considered by some as the cutest member of the weasel family. Its name is derived from the Swedish word ‘meank’. Being part of the weasel family, American minks are similar to many weasels in their physique. They are typically harvested for their fur, which is of excellent color and quality.
The American mink has a long body, which allows the species to enter the burrows of prey. Its streamlined shape helps it to reduce water resistance whilst swimming. The American mink's winter fur is dense, long, and soft. The winter fur's tone is generally very dark blackish-tawny to light-tawny. Color is evenly distributed over the body, with the underside being only slightly lighter than the back. The guard hairs are bright and dark-tawny, often approaching black on the spine. The underfur on the back is very wavy and greyish-tawny with a bluish tint. The tail is darker than the trunk and sometimes becomes pure black on the tip. The chin and lower lip are white. The summer fur is generally shorter, sparser, and duller than winter fur. The thick underfur and oily guard hairs render the pelage water-resistant, with the length of the guard hairs being intermediate between those of otters and polecats, thus indicating the American mink is incompletely adapted to aquatic life. It molts twice a year, during spring and autumn. It does not turn white in winter.
As the common name suggests, this species is native to North America, and it is found from Alaska and Canada southwards through most parts of the United States, aside from dry parts in the southwest. It was also introduced to many areas in Europe and South America. This species is typically associated with water, and is found near streams, rivers, lakes, swamps, and marshes, and also along coastlines. However, they also inhabit drier areas that are not close to the water and sometimes even urban areas, depending on the abundance of food. American minks prefer habitats where there is dense vegetation, as this provides plenty of cover.
American minks are mostly solitary animals, males being especially intolerant of each other. They mark their home range boundaries using musky secretions from their enlarged anal glands. These animals are nocturnal, they are most active during the night, especially close to both dawn and dusk. They are also skilled climbers and swimmers. When searching for food, they are able to swim to depths of 30 meters (100 feet) and dive as far as 5 meters. They dig burrows in riverbanks, lakes, and streams, or use old dens where other mammals have lived, such as muskrats. Sometimes they line their den with dried leaves and grass, and fur from prey. American minks will communicate with a range of cues, including visual, chemical, and auditory signals. These animals are fairly quiet, but they rely heavily on chemical signals for communicating territorial boundaries, as well as reproductive status.
American minks are carnivores. The diet of these animals changes with the season. During summer they eat small frogs and crayfish, as well as small mammals like shrews, rabbits, muskrats, and mice. They sometimes eat ducks and other water birds, as well as fish. In winter, they mostly eat mammals.
American minks are polygynandrous (promiscuous), with both males and females mating with multiple partners. The mating season runs from February in the south to April in the northern part of the range. Gestation is for 40 to 75 days. Young are born in April or May (late spring), and litter sizes usually range from 1 to 8 kits. Their eyes open when they are three and a half weeks old and weaning takes place when they are a month and a half old. They remain with their mother until fall when they go off to establish a territory of their own. Young American minks become reproductively mature and start to breed when they are 10 months old.
The main threat to mink survival is the continuation of the fur market. All Canadian provinces and forty-seven states currently have limited trapping seasons for mink, the length of each season varying according to the area. Another threat is the destruction of the mink’s habitat. Mink heavily depend on aquatic areas, and the creation, enhancement, and maintenance of such habitat allow for the ongoing existence of healthy populations within the species’ range. Environmental contaminants, like mercury and hydrocarbon compounds (such as DDT and PCBs), are another threat, as such chemicals built up in a mink's tissues and are a risk to reproduction and the life of an individual.
This species is relatively common and has a wide distribution across its range but no overall population estimate is available. According to the Game and Wildlife Conservation Trust resource, the total population size of the American mink in the UK is 108,750 individuals. This includes 46,750 minks in England, 52,250 minks in Scotland, and 9,750 minks in Wales. Overall, currently, American minks are classified as Least Concern (LC) on the IUCN Red List and their numbers today remain stable.
American minks are important predators of small mammals throughout their range. They may also affect predator populations (coyotes, snakes, birds of prey), as items of prey.