Willow ptarmigan seeds and berries during the summer and largely subsisting on the buds and twigs of willow and other dwarf shrubs and trees during the winter. The willow ptarmigan is a medium to large ground-dwelling bird and is the most numerous of the three species of ptarmigan. Males and females are about the same size, the adult length varying between with a wingspan ranging from . The weight is . It is deep-chested and has a fairly long neck, a broad bill, short feathered legs and a moderately short rounded tail. In the summer, the male's plumage is marbled brown, with
Arctic hare new fur, from brown or grey in the summer to white in the winter, like some other Arctic animals including ermine and ptarmigan, enabling it to remain camouflaged as their environments change. However, the Arctic hares in the far north of Canada, where summer is very short, remain white all year round. The Arctic hare is one of the largest living lagomorphs. On average, this species measures from long, not counting a tail length of . The body mass of this species is typically between , though large individuals can weigh up to . The Arctic hare is a herbivore,