Lagopus term is of feminine gender, and the specific epithet has to agree with that, the feminine "muta" and "leucura" are correct. The English name "ptarmigan" comes from the Scottish Gaelic name for the bird, , whose origin is unknown. The p- was added due to a mistaken belief in a Greek origin, as if the word were related to the Greek word ("pterón"), 'wing'. The three species are all sedentary specialists of cold regions. Willow ptarmigan is a circumpolar boreal forest species, white-tailed ptarmigan is a North American alpine bird, and rock ptarmigan breeds in both Arctic and mountain habitats
Rock ptarmigan ptarmigan by about 10%. The male's "song" is a loud croaking. The rock ptarmigan is seasonally camouflaged; its feathers moult from white in winter to brown in spring or summer. The breeding male has greyish upper parts with white wings and under parts. In winter, its plumage becomes completely white except for the black tail. It can be distinguished from the winter willow ptarmigan by habitat—the rock ptarmigan prefers higher elevations and more barren habitat; it is also smaller with a more delicate bill. The rock ptarmigan is a sedentary species which breeds across arctic and subarctic Eurasia and North