Ermine

Ermine have a typical weasel form with long body, short legs, long neck supporting a triangular head, slightly protruding round ears, and long whiskers. Their pelage is reddish-brown above and creamy white below in summer, and changes to completely white in winter with the tip of the tail remaining black in all seasons. Males are generally 25% to 50% larger than females however, the sexes of ermine on Haida Gwaii (M. e. haidarum) are more similar in size.

Ermine resemble the long-tailed weasel (Mustela frenata) in general appearance and coloration, but is smaller, has a shorter tail, and has white fur on the inner side of the hind legs. Least weasels (Mustela nivalis) are also similar in appearance to M. erminea, but are smaller and do not have any black on the tail.