Northern black grouse, Eurasian black grouse, Blackgame, Blackcock
Black grouse (Lyrurus tetrix) are large game birds found across the Palearctic. They spend the winter perched in dense forests and females of this species take all responsibility for nesting and caring for the chicks, as typical with most galliforms.
The male's fancy plumage is predominantly black with deep-blue hues on his neck and back, which contrasts the white wingline and undertail coverts, as well as red bare skin above each eye. The female is much drabber and cryptically colored to blend in easily with the dense undergrowth, especially when nesting. The Black grouse, along with the Caucasian grouse, has long outer rectrices (tail feathers) that curl outward and are arranged in a way it resembles the frame of a Greek lyre, hence the genus name, Lyrurus.
Black grouse are found across Europe (Swiss-Italian-French Alps especially) from Great Britain through Scandinavia, Estonia, and across Russia. In Asia, they also inhabit parts of Kazakhstan, Mongolia, China, and possibly Korea. Black grouse inhabit transitionary zones between forests and open clearings, especially steppe, heathland, grassland, and pasture when near agricultural fields. Depending on the season, they will overwinter in dense forests with coniferous and broadleaf trees, such as Scots pine, Siberian larch, silver birch, and Eurasian aspen. Throughout the spring and summer, they favor open spaces. They avoid the most extreme of desert and polar regions.
Black grouse are diurnal birds that spend most of their time on the ground but roost and escape danger in trees. They spend winters in large flocks in dense forests but in spring and summer, they are usually found in open spaces where they seek potential mates and raise broods. Black grouse are usually silent but during the breeding season, males produce low bubbling croons that can be heard at long distances. Females have a cackling or warbling call.
Black grouse have a herbivorous diet that varies with the season. During wintertime, they feed primarily on the leaves and buds of coniferous and broadleaf trees, but in spring and summer they switch their diet to berries, shoots, and stems of cranberries, bog bilberries, myrtleberries, and other Vaccinium shrubs.
Black grouse have a very distinctive and well-recorded courtship ritual. Every dawn in the spring, male grouse begin competition with other males in hopes of attracting a female to mate with. They will display to signal their territory and vigor by fanning out their elaborate lyre-shaped tails and inflating their necks on the designated open ground called a lek. Their song consists of a long, dove-like bubbling coo or murmur. Black grouse females visiting the lek decide the overall healthiest male, though not all females may arrive at every lek. Depending on location, these leks may contain more than 40 birds, 150 and even 200 birds have been recorded. After mating the female will fly away from the site to a suitable nesting site with an abundance of dense shrub or tall vegetation, often located at a tree base in between roots, under low branches, beside a boulder. Rarely, a raptor's or corvid's nest 7 meters (23 ft) off the ground can be used. A nest 23-28 cm (9.1-11.0 in) wide by 10-11 cm (3.9-4.3 in) deep is scraped out on the dirt floor and cushioned with grasses, sticks, leaves, and feathers. Laying usually occurs in May-June. The female lays 6-11 pale buff eggs speckled brown and incubates them alone for about 23-28 days. The chicks consume invertebrates, transitioning to more plant matter as they mature. By around 10-14 days and so forth, the young are capable of short flights.
The major threats to Black grouse include continuous destruction and fragmentation of their habitat, hunting, disturbances on breeding grounds, collisions with powerlines and increasing predation by mammals and birds of prey.
According to IUCN Red List, the total population size of the Black grouse is 8,000,000-14,000,000 mature individuals. The European population consists of 1,220,000-2,040,000 lekking males, which equates to 2,450,000-4,080,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.
