What type of bird is this?

The Ptarmigan is one of the three or four species of partridgelike grouse of cold regions, belonging to the genus 'Lagopus' of the grouse family, 'Tetraonidae'. They undergo seasonal changes of plumage, from white against winter snowfields to gray or brown, with barring, in spring and summer against tundra vegetation. These species differ from other members of the grouse family in having the toes covered with stiff feathers above and below. The common ptarmigan ranges in the British Isles, Europe, and North America, where it is called Rock Ptarmigan.

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 and in Canada, where it is the official bird for the territory of Nunavut, and the official game bird for the province of Newfoundland and Labrador. Ptarmigan survive winter in the Arctic and mountain-top fastnesses by browsing shrubs and scratching up lichens and leaves; they burrow in the snow to sleep. Males, which have harsh cackling calls, begin to display socially in early spring and then separate and display singly in adjoining territories.