Distinguishing Features – Length: male 43 cm; weight: .56 kg; female: 40 cm; weight: .45 kg.
Adult Male – summer: Bill black. Iris brown. Toes and claws dark brown, the edges of the latter yellowish-grey. Head and neck bright chestnut, the feathers on the back part of the latter and crown of the head barred with black, and tipped with whitish.
The back, some of the wing-coverts, the nearer secondary quills, the four upper tail-feathers, the anterior part of the breast, and part of the sides under the wings, variegated with brownish-black, chestnut and white, the feathers being of the first colour in the middle, and transversely barred with the second towards the end, while the terminal margin is of the last. Most of the coverts, all the primaries, and the greater number of the secondaries, with the whole under surface of the wings, the middle of the breast, the abdomen, legs and feet, pure white, the shafts of the primaries are more or less brown, excepting towards the ends.
Tail-feathers are brownish-black, with the tips white, as is the basal portion of the outer web of the outermost. The superciliary membranes are vermilion.
Adult Female – summer: The superciliary membrane is much smaller, but of the same colour, as are the wings and tail. The head, neck, breast, abdomen, sides, as well as the upper parts, are variegated in a manner resembling the back of the male, but with the black spots larger, and the transverse bars of light brownish-red broader and less numerous; the lower surface much lighter.
Circumpolar; northern Canada, Alaska, Scandinavia and northern Russia; tundra, preferring moister and better vegetated country than its cousin, the Rock Ptarmigan.
Primarily mosses and lichens; berries when available.
Ptarmigan are arctic grouse. They have a separate summer and winter plumage. In winter, they turn primarily white from their rufous summer colouration. In short, they are well camouflaged against predation.