Plump, chickenlike bird often found near willows; also resides in more open tundra. Plumage changes throughout the year. In winter, both sexes are pure white with black outer tail feathers. As summer progresses, male develops rich rufous head and neck and brownish back; in winter, lacks black eyeline shown by Rock Ptarmigan. Summer female is paler golden-brown with intricate black and white markings. Female nearly identical to Rock Ptarmigan; look for slightly thicker bill. Female distinguished from White-tailed Ptarmigan by warmer plumage in summer and black outer tail feathers. Also note habitat differences of White-tailed. Vocalizations include a comical nasal chuckle and various clucking notes.