White-tailed ptarmigan entry into the respiratory tract. The most obvious adaptation is this bird's cryptic coloration, which enables it to blend in with its environment and avoid predation by golden eagles or other birds of prey. To conserve energy during the winter months, the ptarmigan avoids flight as much as possible and roosts in snowbanks. The white-tailed ptarmigan is listed as being of "Least Concern" by the International Union for Conservation of Nature. This is because, although populations may be in slight decline, its range is too wide and the total number of birds too large to fit the criteria for being
Arctic hare new fur, from brown or grey in the summer to white in the winter, like some other Arctic animals including ermine and ptarmigan, enabling it to remain camouflaged as their environments change. However, the Arctic hares in the far north of Canada, where summer is very short, remain white all year round. The Arctic hare is one of the largest living lagomorphs. On average, this species measures from long, not counting a tail length of . The body mass of this species is typically between , though large individuals can weigh up to . The Arctic hare is a herbivore,