Mink, ermine and marten are found throughout forested areas of the Tongass National Forest. All are members of the weasel family and are agile, sleek predators that sport plush, luxurious coats, especially in winter. All three species are chiefly nocturnal, but they sometimes are seen during the day. Males tend to be about 25 percent larger than females.
Ermine are brown in summer, with a black tip to the tail, and turn white in winter. They are also known as short-tailed weasels. Ermine are the smallest of the three species. They weigh about a half-pound and are about 14 inches long, including their tail. Their size allows them to squeeze into the holes of mice and voles, their primary prey.
Mink tend to be chocolate brown with scattered white patches. They weigh about three pounds and average 19 to 29 inches, including their tail. Mink are excellent swimmers and of the three, mink are most often seen foraging on beaches and intertidal areas. Marten and ermine favor a diet of rodents, where mink are more generalists and will eat just about anything they can catch and kill, including fish, crabs, shellfish, insects and small mammals.
Marten vary in color from pale yellow to cinnamon brown or dark brown. They weigh three to five pounds and are 19 to 29 inches long, with an eight-inch tail. Marten are often described as cat-like, and their ears are more prominent than those of mink or ermine. They feed primarily on mice and voles, but will also eat berries, birds, and eggs. Marten fur is known as sable, and marten are Alaska's most widely-trapped furbearing animal.
What to look for: As a rule, these members of the weasel clan don't sit still very long. They tend to move quickly and to dart from cover to cover, hunting and avoiding predators such as eagles and goshawks. Morning and evenings are the best time to look for them.