Theblack grouse (Lyrurus tetrix), also known asnorthern black grouse,Eurasian black grouse,blackgame orblackcock,[4] is a largebird in thegrouse family. It is asedentaryspecies, spanning across thePalearctic inmoorland andsteppe habitat when breeding, often near wooded areas. They will spend the winter perched in dense forests, feeding almost exclusively on the needles of conifers. The black grouse is one of two species of grouse in the genusLyrurus, the other being the lesser-knownCaucasian grouse.
The female is greyish-brown and has a cackling or warbling call. She takes all responsibility for nesting and caring for the chicks, as typical with mostgalliforms.
The black grouse's genome was sequenced in 2014.[5]
The male and female are sometimes referred to by theirfolk names,blackcock andgreyhen, respectively. These names first occur in the literature withJohn Ray in 1674.[10]Heathcock andHeathhen are also common names.[11]
The black grouse has six recognized subspecies.[12] Black grouse populations differ slightly in size and coloration, with birds increasing in size further east of their range:[13]
The black grouse is a large bird with males measuring roughly around 60 centimetres (24 inches) in length and weighing 1,100–1,250 g (2 lb 7 oz – 2 lb 12 oz), sometimes up to 2,100 g (4 lb 10 oz), with females approximately 45 cm (18 in) and weighing 750–1,100 g (1 lb 10 oz – 2 lb 7 oz).[13] The cock'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. On the other hand, the hen 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 outerrectrices (tail feathers) that curl outward and arranged in a way it resembles the frame of a Greeklyre, hence the genus name,Lyrurus.
Black grouse are adapted to an extensive array of habitats across Eurasia, though most frequently utilize the transitionary zones between forests and open clearings, especiallysteppe,heathland,grassland andpasture when near agricultural fields. Depending on the season, they will overwinter in large flocks in dense forests, and feed primarily on the leaves and buds of coniferous and broadleaf trees, such asScots pine,Siberian larch,silver birch, andEurasian aspen. Throughout the spring and summer, they tend to favor open spaces to seek potential mates and raise broods, switching their diet to berries, shoots and stems ofcranberries,bog bilberries,myrtleberries, and otherVaccinium shrubs.[13] They avoid the most extreme of desert and polar regions.
Although this species has declined throughout most of its range in westernEurope, it is not considered to be vulnerable globally due to the large population (global estimate is 15–40 million individuals) and slow rate of decline.[1] Its decline is due toloss of habitat, disturbance, predation byfoxes,crows, etc., and small populations gradually dying out.[citation needed]
The IUCN implemented a Black Grouse Action Plan 2007–2010. This has looked at local populations that are vulnerable to theextinction vortex. For example, in Styria, Austria.[citation needed]
In the United Kingdom black grouse are found in upland areas of north Wales, thePennines and most of Scotland. Best looked for on farmland and moorland with nearby forestry or scattered trees. They have traditionallek sites where the males display.[citation needed]
In France there has been much work regarding the birds and their risk of flying intoski-lifts.[17]
From 1950 to 2000, local black grouse populations have steadily diminished inManchuria and northeastern China by about 39%, with birds being most affected (and possibly extirpated) in theJilin Province. Though the exact causes for local declines remain largely unclear, habitat loss and excess hunting have played a part in the overall reduction. Shifts in their location, however can happen concurrently with the depletion over decades, so short-term research projects may not provide much proof of driving forces behind population alterations.[18]
Based on historical info gathered from various sources (including wildlife surveys and scientific papers), aspen, birch, and poplar make up the black grouse's staple diet and habitat. The climate and precipitation during the month of June is also linked to the breeding success of black grouse.[18]
Egg ofTetrao tetrix tetrix -MHNTBlack grouse - rolling and hissing sounds, recorded in 2022 in the northern AlpsBlack grouse - recorded in 2022 in the northern Alps. Mostly rolling sounds audible.
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 hen 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 designated open ground called alek. Their song consists of a long, dove-like bubbling coo or murmur. Black grouse hens visiting the lek decide the overall healthiest male, though not all females may arrive at every lek.
In western Europe, these leks seldom contain more than 40 birds; inRussia, 150 is not uncommon and 200 have been recorded.[14]
When mated successfully, she 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, or extremely rarely, a used raptor's or corvid's nest 7 metres (23 ft) off the ground. A dent (23–28 cm or 9–11 in wide by 10–11 cm or 4–4+1⁄2 in deep) is scraped out on the dirt floor and cushioned with grasses, sticks, leaves, and feathers. About 6–11 pale buff eggs speckled brown are then laid in the nest, incubated for approx. 23–28 days. The chicks consume invertebrates, transitioning to more plant matter as they mature. By around 10–14 days and so forth, they are capable of short flights.[13]
^abBirdLife International and NatureServe (2014) Bird Species Distribution Maps of the World. 2012. Lyrurus tetrix. In: IUCN 2014. The IUCN Red List of Threatened Species. Version 2014.3."The IUCN Red List of Threatened Species". Archived fromthe original on 27 June 2014. Retrieved27 June 2014.. Downloaded on 2 June 2015.
^Boev, Z. (1997). "The Black Grouse, Tetrao tetrix (L., 1758) (Tetraonidae, Aves), a disappeared species in Bulgaria (Paleolithic and Neolithic records)".Anthropozoologica.25–26:643–646.
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