© Copyright: Images: Jari Peltomäki, Kari Pihlaviita, M. & W. von Wright: Svenska fåglar (Kansalliskirjasto, The National Library of Finland). Recording: Jan-Erik Bruun. All rights reserved.
- Name also: Rock Ptarmigan, Snow Chicken, Partridge
- Family: Pheasants and partridges – Phasianidae
Subfamily: Grouse – Tetraoninae
- Appearance: In summer greyish with white wings. In winter plumage almost totally white, though males have short dark facial stripes between their eyes and beak.
- Size: Length: 31–55 cm, wingspan 54–60 cm, weight 450–600 g.
- Nest: In a shallow depression on open rocky ground, lined with a few feathers.
- Breeding: Usually 7–11 eggs laid in May–June and incubated by female for 21–26 days. Fledglings learn to fly within 5–15 days.
- Distribution: On rocky and sparsely vegetated ground on arctic fells. In Finland only found on the highest fells in Northern Lapland. Finnish population estimated at 4,000–9,000 pairs.
- Migration: Sedentary, remaining on the high fells even in extreme conditions.
- Diet: The buds, shoots and leaves of various arctic upland plants. Fledglings initially feed on insects, but soon shift to a herbivorous diet.
- Calls: Courtship call similar to call of Garganey, a four-syllable croaking sound.
- Endangerment: Least concern, protected. Also globally Least concern. Like other members of the same subfamily Ptarmigans may be hunted as game birds in Finland during the season. In northernmost Finnish Lapland Ptarmigans and Willow Grouse may still be trapped using traditional snares.
Ptarmigans are monogamous. They are slightly smaller than the similar Willow Grouse. They change their plumage seasonally. Males have four different plumages and females three. In their summer plumage Ptarmigans are greyer than Willow Grouse. In winter, like the Willow Grouse, they are almost totally white, except for their dark outermost tail feathers, and a dark facial stripe on males between their eyes and beak.
Ptarmigans’ beaks are black, and smaller than the beak of the Willow Grouse. Their irises are dark brown and their legs are covered with feathers.