Ptarmigan

Three moults

No other British bird undergoes three complete moults per year — the ptarmigan changes its plumage completely to match each season. In summer, males are speckled brown and grey, cryptically matching lichen-covered boulders. In autumn, the plumage becomes grey-brown with white patches. In winter, the bird is pure white (except for a thin black bill and, in males, a red eyebrow). Each transition is gradual, and at any given time a bird may be partly moulted.

Feathered feet

Ptarmigan have feathered toes — the only grouse species with this adaptation. The feathers act as snowshoes, increasing foot surface area and grip on snow. This is one of several cold-weather adaptations: the nasal passages are specially designed to warm Arctic air; the dense feathering even covers the nostrils; and the bird can roost buried in snow for insulation.

British range

In Britain, ptarmigan are confined to the high plateaux of the Scottish Cairngorms, Grampians, and a few other Highland mountain ranges. The British population is at the southern edge of the species’ range and is estimated at 2,000–10,000 pairs. The population has declined significantly due to a complex of factors including climate change (warmer, snowier winters disrupt the camouflage; exposed mountain tops losing suitable habitat), and predation pressure.

Tame behaviour

Ptarmigan are remarkably approachable — they crouch motionless and rely on camouflage rather than flight. Walkers in the Cairngorms regularly come within a metre of sitting ptarmigan before the bird moves. When it does move, it tends to walk or run rather than fly.