The Black Grouse (Lyrurus tetrix) shows striking differences between the sexes. The male, or blackcock, is 49–58 cm long and weighs 1,000–1,400 grams, entirely black with a glossy blue-violet sheen, bright red wattles above the eyes, white wingbars and a white undertail; its most striking feature is the outward-curving, lyre-shaped tail, fanned open during display. The female, or greyhen, is much smaller at 40–45 cm and 750–1,000 grams, camouflaged in barred brown-black plumage with a shallow-forked tail; both sexes show a clear white wingband in flight, and the wingspan runs to roughly 65–80 cm.
Found throughout Sweden except the highest mountains, the Black Grouse is a year-round resident with a population of 150,000–300,000 pairs, classed as Least Concern (LC), favouring open bogs, clearcuts and mountain birch forest where woodland meets open ground. Each spring, males gather at traditional display grounds known as leks, where they compete for females by bubbling, leaping and staging mock fights; the male's lekking call is a continuous, muffled "bubb-bubb-bubb-bubb" that can carry several kilometres, mixed with an explosive hissing "tschu-äsch" during confrontations, while the female's call is a hard, cackling note. After mating, the female alone raises the brood, laying 6–10 eggs in a simple ground scrape hidden under brush and incubating them for roughly 25–27 days; the precocial chicks follow her from their first day and depend on insects for protein during their early weeks. Adult diet shifts with the seasons — birch buds and catkins in winter, supplemented by willow and pine shoots, and blueberry shrub, berries and herbs in summer — and on cold, clear winter days the birds are often seen perched in birches, feeding on buds.
Read about this species in Swedish →