Systematic classification and distribution
It is a sedentary species that populates the arctic and subarctic area of Eurasia and North America. There are also isolated populations in Scotland, the Pyrenees and the Alps, where it lives from 2000 to 3400 meters above sea level.
Rock ptarmigan in winter
Rock ptarmigan (photo www.biologie.uni-hamburg.de)
Total length: 32.5-41 cm
Wingspan: 54-66 cm
Average weight: 420-540 grams
Solid body, about like a pigeon, with a superior tawny-yellowish plumage, speckled with dark brown, with whitish abdomen (in the female), brownish-gray, speckled with dark brown, with a whitish abdomen (male); in young people it is more similar to that of females.
The beak is relatively robust, short and black.
The head is relatively small, with red above-ocular caruncles, more developed in the male.
The wings are always white, wide and rounded.
The tail is of medium length, black with whitish border.
The legs are of medium length, completely feathered all year round.
The male is normally larger, with darker summer coloring, more developed caruncles and black rendine in winter.
Seasonal dimorphism is characteristic. The livery of the male in winter is entirely white with black tail and streak from the base of the allocheck beak.
It lives in stony and rocky high altitude grassy areas. Mostly diurnal-crepuscular, solitary, in pairs or in small groups.
Sedentary, nesting, partly erratic.
Food: mainly vegeterian-insectivorous.
It reproduces in May-July. It nests in small holes in the ground, under stones or among dwarf shrubs. It lays 5-10 yellowish or brownish-yellow eggs with showy brown spots. The incubation period is 20-21 days, with one brood per year. The offspring is nestproof.
Singing consists of a series of guttural sounds. The flight is fast, with rapid beats, partially gliding.
The maximum age registered free is more than 6 years.