White-tailed ptarmigan summer plumage. The finely-barred greyish coloration on the back makes it easy to distinguish this species from the much browner willow ptarmigan and rock ptarmigan. Both sexes maintain white tail and wing feathers all the year and males can be identified by their reddish eyecombs (fleshy growths above the eye), also present year-long. In general this bird is silent but it sometimes makes quiet, low-pitched hoots and soft clucking noises. The white-tailed ptarmigan is an alpine species, a permanent resident of the high mountains above or near the timber line. It occupies open country and flies a great deal more
Snow camouflage to escape the conclusion that cryptic brown summer plumage becomes a liability in snow, and white plumage is therefore another cryptic adaptation." All the same, he notes, "in spite of winter plumage, many Ptarmigan in NE Iceland are killed by Gyrfalcons throughout the winter." Some animals of the far north, like the showshoe and Arctic hares, Arctic fox, stoat, and rock ptarmigan change their coat colour (by moulting and growing new fur or feathers) from brown or grey summer camouflage to white in the winter; the Arctic fox is the only species in the dog family to do so. However,