The ptarmigan is the only bird that lives above the treeline in winter.
The ptarmigan surmounts the problem of energy loss in winter by eating large quantities within a short time, followed by a period of rest in the shelter of a snow hollow. Ptarmigans feed on buds and new shoots of bushes, leaves, berries and seeds.
In bad weather and extreme cold the ptarmigan retreats for longer periods to its «igloo». If disturbed by humans, a great deal of energy may be lost, which can be fatal.
Its legs are covered with feathers, right down to its toes. Being very light in weight, it doesn’t sink so easily into the snow.
Seasonal variation in plumage - pure white in winter and greyish-brown camouflage in summer – is complex, and differs from one sex to the other.