Western Capercaillie

The Western Capercaillie, known scientifically as Tetrao urogallus, is the largest member of the grouse family, a robust bird that commands the attention of those fortunate enough to encounter it. The most sizable specimen on record, a captive individual, tipped the scales at an impressive 7.2 kilograms (16 pounds). Exhibiting pronounced sexual dimorphism, the male is nearly twice the size of the female, a trait that is particularly striking during their elaborate courtship displays.

Identification Tips

The male Western Capercaillie, or cock, is a majestic bird with a length ranging from 74 to 85 centimeters and a wingspan stretching from 90 to 125 centimeters. Weighing an average of 4.1 kilograms, the cock boasts dark grey to dark brown body feathers and a lustrous dark metallic green on the breast. The belly and undertail coverts show a variable pattern from black to white, depending on the subspecies. The female, or hen, is considerably smaller, with a body length of 54–64 centimeters, a wingspan of 70 centimeters, and an average weight of 1.8 kilograms. Her plumage is a mottled brown with black and silver barring above, and a lighter, buffish yellow below. Both sexes feature a distinctive white spot on the wing bow and red skin above each eye, known as "roses."

Habitat

The Western Capercaillie is a forest dweller, favoring old, mature coniferous forests with a rich understory of Vaccinium species. These birds require a habitat with a diverse species composition and an open canopy structure to thrive.

Distribution

This non-migratory bird breeds across Europe and the Palearctic, from the northern reaches to the mountainous coniferous belts of warmer regions. Once extinct in Scotland, it has been reintroduced from Swedish stock.

Behaviour

The Western Capercaillie is a ground-dwelling bird that is most active during the day. It roosts in trees at night, and in winter, it may spend extended periods in the canopy, feeding on conifer needles. The males are territorial, with a range of 50 to 60 hectares, while females occupy about 40 hectares. These birds are not adept fliers, relying on short bursts and gliding to move through their forested habitat.

Song & Calls

The male's courting song is a unique series of double-clicks that accelerate into a popping sound, followed by scraping noises. This vocal performance is part of their elaborate display to attract females.

Breeding

The breeding season begins in spring, with males establishing territories and performing both tree and ground courtship displays. The hen lays a clutch of eggs, usually eight, but numbers can vary. Incubation lasts around 26–28 days.

Similar Species

The Western Capercaillie can be confused with the Black Grouse, but the latter is smaller and lacks the white wing spot and the red "roses" above the eyes.

Diet and Feeding

A highly specialized herbivore, the Western Capercaillie feeds predominantly on bilberry leaves and berries, with a winter diet of conifer needles. Chicks require a protein-rich diet and consume a variety of insects.

Conservation status

The IUCN lists the Western Capercaillie as "Least Concern," though certain populations in central Europe are declining. Habitat degradation and increased predation are significant threats to this species.