Species Guide: Western capercaillie (Tetrao urogallus)
Family: Phasianidae
The Western capercaillie, also called the Eurasian capercaillie, wood grouse or “cock-of-the-woods”; is the largest living species of grouse. It is a heavy, ground-dwelling forest bird native to boreal and temperate forests across much of Europe and the Palearctic. The species is especially famous for the dramatic, loud courtship displays conducted by males in spring.
Appearance
Adult males are large and showy: bulky bodies, a fan-shaped tail, glossy iridescent green/blue on the breast and throat, dark grey to black body plumage, and conspicuous red combs above the eye. Males often have white wing and tail markings and a stout, pale bill. In full display, they puff up the neck feathers, fan the tail, and strut with wings lowered. Males are dramatically bigger than females (see Biometrics).
Females are smaller and cryptically colored, mottled brown and buff, which provides camouflage while nesting on the ground. Hens lack the bright iridescence and red eyebrow combs of males and have more compact tails. Juveniles and first-year birds show subtler patterns and less contrast than adults.
Diet
Capercaillie diet varies seasonally. In summer and autumn, they feed on berries (notably bilberry/blueberry), buds, leaves, and a variety of herbaceous plants; chicks rely heavily on insects and other invertebrates for protein. In winter, when ground food is snow-covered, adults spend long periods roosting and feeding in conifers, eating needles and buds of spruce, pine, and fir. To grind tough plant material, they swallow small stones (gastroliths); their gut morphology (large ceca/appendices) helps ferment and digest needles. Recent molecular studies of droppings show their diet may be more varied than older descriptions suggested.
Habitat
Western capercaillie favour mature, patchy coniferous and mixed forests with a well-developed understory (heather, bilberry, young pines) and relatively low human disturbance. They use different forest structures seasonally spending winters higher in conifers for food and shelter and using open lekking arenas and adjacent cover in spring for displays. Their distribution covers large parts of northern, central, and eastern Europe and extends into Siberia and parts of Asia. Local populations are sensitive to forest fragmentation and certain forestry practices.
Western Capercaillie Geographic Range1
Behavior
Social and mating behavior
Capercaillie are largely solitary outside the breeding season. In spring, males gather or visit traditional display sites (leks) where they perform loud, ritualized displays to attract females: tail fanning, wing-drooping, head-thrown-back posture, and repeated vocalizations. Males may be territorial around display arenas; dominant males secure most matings. Females select nest sites on the ground in dense cover and raise chicks alone.
Call and sounds
The male’s display includes a wide repertoire: low booming or “hooting” notes, a series of loud, popping or clicking calls, and a rattling whoosh as wings are used or feathers vibrate during displays. These sounds carry well across forest openings and are a classic spring sound in capercaillie country. Several wildlife and sound archives include recordings of the call.
Life cycle and reproduction
Breeding occurs in spring. After mating, the hen builds a shallow ground nest lined with vegetation. Clutch size typically ranges up to about 6–12 eggs (varies with region and condition). Incubation is provided solely by the hen and lasts a few weeks; chicks are precocial — leaving the nest soon after hatching and feeding on insects early in life. Juvenile survival is highly weather-dependent: warm, dry conditions favor good chick survival, while cold and rainy periods can cause high mortality.
Ad Space
Biometrics
| Body Length | 60-87 cm |
| Wing Length | 87-125 cm |
| Body Weight | 5000 grams |
| Longevity | 3-7 Years |
Natural Predators
Predators vary by life stage and region. Eggs and chicks are taken by mammals (e.g., foxes, martens, mustelids) and birds of prey or corvids; adult capercaillie may fall to raptors (goshawks, eagles) or mammalian predators where encounters occur. Predation pressure on chicks is a key factor in local recruitment and population fluctuations. Habitat loss and disturbance can increase exposure to predators by reducing available cover.
Relationship to Humans
Capercaillie have a long cultural presence across Europe: their feathers and images appear in folklore, hunting traditions, and local toponyms. The species’ dramatic display made it a subject of rural tales and fables in Scotland, Scandinavia, and central Europe, often portrayed as a proud “cock of the woods.” Historically, capercaillie were hunted as game (their size made them prized); they also entered heraldry and regional stories. In recent decades, human attitudes have shifted from hunting and sport to conservation in many places, with protected areas and management measures aimed at sustaining populations.
Conservation Status
Global status: the species is assessed as Least Concern at a global level by broad conservation assessments, but this masks strong regional differences. Some central and western European populations are declining, fragmented, or locally extinct due to habitat loss, forestry practices, recreational disturbance, and predation pressures.
Regional trends: In parts of central Europe (e.g., some lowland and fragmented mountain forests), numbers have fallen markedly, and conservation measures target habitat restoration, adjusted forest management, protection of lek sites, and limits on disturbance during the breeding season. Conservation planning is often regionally focused because the species’ needs and threats vary locally.
U.K.
Conservation Status
Global
Conservation Status
Ad Space
Related Articles
CITATIONS
- By the author of the work and the IUCN Red List spatial data, CC BY-SA 4.0, [Accessed 09/10/2025] ↩︎
References
- Golley, M. (2016) Field guide to the birds of Britain and Ireland. London, England: Bloomsbury. [Accessed 09/10/2025]
- Lovette, I. et al. (2016) The Cornell Lab of Ornithology, handbook of bird biology. Third edition. Chichester: Wiley. [Accessed 09/10/2025]
