Mustela vison
The American Mink was introduced into Europe from North America in the early 1900s for fur farming. Escapes from farms have now established widespread wild populations in Europe.
The American Mink is approximately the size of a Western Polecat, about 30–47 cm long, with a tail measuring 13–23 cm. The male weighs 1–1.5 kg; the female is significantly smaller and rarely weighs more than 0.8 kg.
American Mink from fur farms can be a variety of colours, ranging from white to bluish black, while wild animals are normally dark brown with white spots on the lower lip and throat. They are almost never light coloured on the snout.
The American Mink is a good swimmer and prefers living near water, both in fresh water environments and in coastal areas, wherever there are stones, rocks, or marsh, which helps provide cover, but it will also utilise drier habitats. It is normally nocturnal, but may sometimes be seen during the day, and it can sometimes be found in harbours and other man-made habitats.
American Mink are also active during the day and not particularly shy. AK.
The American Mink is less inclined to dig a den than Western Polecat, but prefers to sleep under tree roots, in hollow trees, under harbour piers, in sheds or boats, as well as on the beach, hidden between rocks, or simply in taller vegetation near the water.
The tracks resemble those of Western Polecat. They are somewhat smaller, but the differences aren’t easy to see—except for the fact that the mink often moves along shorelines when looking for food. The claws of Western Polecat are longer, especially on the front feet, and often leave a clearer print.
American Mink footprints in the sand. AK.
The American Mink has five toes on each foot. The front footprints are about 3 cm long and 4 cm wide. The feet have narrow webbing between the toes that is visible now and then in the print. The length of the stride is about 40–90 cm.
The gait of the American Mink resembles that of Western Polecat, but the mink moves more lightly in deep snow. It travels in a straight line for long stretches when not foraging for food, even in snow. It can forage under snow or suddenly disappear into a hole in the ice when prey is detected. You can find mink tracks along shores with soft sand or mud; when the prints are clear, the dragged tail will leave a visible track.
American Mink feed mostly on fish and crustaceans but also hunt small mammals, birds, amphibians, crabs, and insects. They also hunt small ducks and can kill game birds. The scat is similar to that of Western Polecat and is cylindrical, slightly twisted, with a long point at one end, and 5–10 cm long and about 1 cm thick. It can often be identified because of its dark colour and the obvious remains of fish scales and bones. If the scat contains copious fish remains, it becomes loose and can easily crumble. Fresh scat has a strong sulphurous musty smell. The scat is not always left in latrines and is often visible on stones, tree stumps, bridges, etc. Otter scat has a sweeter smell than that of American Mink.
Paired footprints of an American Mink. OJ.
American Minks will kill a wide range of prey, including voles and ducks. HS.
The American Mink prefers eating its prey in secluded areas, and if you happen upon such a place, you will always see remains, typically of crabs, prawns, fish, eggshells, etc.
Fish scales and fins, among other items, may be found at a mink’s feeding site. EHA.
