The Western Capercaillie (Tetrao urogallus) is Sweden's largest forest grouse and shows an extreme size difference between the sexes. The male is a powerful bird, 74–90 cm long with a wingspan of 90–125 cm and weighing 3.5–6.5 kg, largely dark grey-black with a glossy, metallic green breast, brownish wings, a strong pale bill and bare red wattles above the eyes; the broad, rounded tail is fanned out during display. The female is considerably smaller, 54–64 cm long and weighing only 1.5–2.5 kg, with a rusty-brown, barred plumage and a distinctive rust-coloured patch on the breast.
The species is famous for its lek: on traditional display grounds, often in old pine forest or at the edges of mires, males gather at dawn from March to May to perform an odd, muted courtship song in four phases — an opening series of clicks, an accelerating drum-roll, a brief "cork-pop," and a final hissing "whetting" during which the bird is temporarily almost deaf; females visit the lek and mate with the dominant males. The female alone incubates 6–10 yellow-brown, spotted eggs for around 24–26 days in a simple ground scrape, and the precocial chicks soon forage for themselves, relying heavily on protein-rich insects in their first weeks. Adults switch to pine needles as their almost exclusive, nutrient-poor winter food, supplemented by bilberry shrub, berries, buds and shoots once the snow melts. Found throughout Sweden's coniferous forest belt from Götaland to the edge of the mountains, the Western Capercaillie is Near Threatened on Sweden's Red List, its dependence on old, varied forest with pine, bilberry undergrowth and moist ground making it vulnerable to modern forestry; it is a sedentary resident that spends its life within a limited area of forest.
Read about this species in Swedish →