The rock ptarmigan (Lagopus muta) is a medium-sized game bird in the grouse family. It is known simply as the ptarmigan in the UK. It is the official bird for the Canadian territory of Nunavut, where it is known as the aqiggiq (ᐊᕿᒡᒋᖅ), and the official game bird for the province of Newfoundland and Labrador. In Japan, it is known as the raichō (雷鳥), which means 'thunder bird'. It is the official bird of Gifu, Nagano, and Toyama Prefectures and is a protected species nationwide. Unlike many arctic bird species, ptarmigan do not gain substantial mass to hibernate over winter. 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 outer tail feathers and eye line. It can be distinguished from the winter willow ptarmigan by habitat and markings—the rock ptarmigan prefers higher elevations and more barren habitat. It also has a slender bill and a black eye stripe, which is absent in the willow ptarmigan. (Source: Wikipedia.org, CC BY-SA)