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
Camouflage the brain to vary its opacity. By controlling chromatophores of different colours, cephalopods can rapidly change their skin patterns and colours. On a longer timescale, animals like the Arctic hare, Arctic fox, stoat, and rock ptarmigan have snow camouflage, changing their coat colour (by moulting and growing new fur or feathers) from brown or grey in the summer to white in the winter; the Arctic fox is the only species in the dog family to do so. However, Arctic hares which live in the far north of Canada, where summer is very short, remain white year-round. The principle of varying