Black grouse

Appearance

The black grouse is a large bird with males measuring roughly around 60 centimetres in length and weighing 1,100–1,250 grams, sometimes up to 2,100 grams, with females approximately 45 cm and weighing 750–1,100 grams. 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 outer rectrices that curl outward and arranged in a way it resembles the frame of a Greek lyre, hence the genus name, "Lyrurus".

Naming

The black grouse was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his "Systema Naturae" under the binomial name "Tetrao tetrix". Both "Tetrao" and "tetrix" come from Ancient Greek words referring to some form of game bird. The black grouse is now placed in the genus "Lyrurus" that was introduced in 1832 by the English naturalist William Swainson.

The male and female are sometimes referred to by their folk names, "blackcock" and "greyhen," respectively. These names first occur in the literature with John Ray in 1674. "Heathcock" and "Heathhen" are also common names.The black grouse has six recognized subspecies. Black grouse populations differ slightly in size and coloration, with birds increasing in size further east of their range:

⤷  "L. t. baikalensis" - southeastern Siberia to northern Mongolia and northwestern Manchuria
⤷  "L. t. britannicus" - Scotland, Wales and northern England
⤷  "L. t. mongolicus" - eastern Kyrgyzstan and northwestern China towards eastern Kazakhstan, south-central Siberia and western Mongolia
⤷  "L. t. tetrix" - Scandinavia to southern France and northern Italy and northeastern Siberia
⤷  "L. t. ussuriensis" - eastern Siberia and northeastern China including northwest Korea.
⤷  "L. t. viridanus" - southeastern Russia to southwestern Siberia

Distribution

Black grouse can be found on open habitats across Europe from Great Britain through Scandinavia, Estonia and across Russia. Although believed to once to live in Ireland, it now no longer resides there. In Eastern Europe they can be found in Hungary, Latvia, Lithuania, Poland, Belarus, Romania and Ukraine. There is a population in the Alps, and isolated remnants in Germany, France, Belgium and the Netherlands. It formerly occurred in Denmark, but the Danish Ornithological Society has considered it extinct since 2001. The species disappeared from Bulgaria in the 19th century. In Asia, a huge portion of their population can be found in Russia, though they also inhabit parts of Kazakhstan, Mongolia, China, and possibly Korea.

Status

Although this species has declined throughout most of its range in western Europe, it is not considered to be vulnerable globally due to the large population and slow rate of decline. Its decline is due to loss of habitat, disturbance, predation by foxes, crows, etc., and small populations gradually dying out.

The IUCN implemented a Black Grouse Action Plan 2007–2010. This has looked at local populations that are vulnerable to the extinction vortex. For example, in Styria, Austria.

In the United Kingdom black grouse are found in upland areas of Wales, the Pennines and most of Scotland. Best looked for on farmland and moorland with nearby forestry or scattered trees. They have traditional lek sites where the males display.

They have declined in some parts of the UK, having disappeared from many of their former haunts. They are now extirpated in Lancashire, Derbyshire, Exmoor, East Yorkshire, New Forest, Nottinghamshire, Worcestershire, Quantock Hills, Cornwall, Dartmoor, Kent, Wiltshire and Surrey.

A programme to re-introduce black grouse into the wild started in 2003 in the Upper Derwent Valley area of the Peak District in England. 30 grouse were released in October 2003, followed by 10 male grouse in December 2004 and a further 10 males and 10 females in April 2005. The programme is being run jointly by the National Trust, Severn Trent Water and Peak District National Park.

Conservation groups helping to revive the black grouse include the RSPB and the Game & Wildlife Conservation Trust.

In France there has been much work regarding the birds and their risk of flying into ski-lifts.

From 1950 to 2000, local black grouse populations have steadily diminished in Manchuria and northeastern China by about 39%, with birds being most affected in the Jilin 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.

Based on historical info gathered from various sources, 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.

Habitat

Black grouse are adapted to an extensive array of habitats across Eurasia, though most frequently utilize the 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 large flocks in dense forests, and feed primarily on the leaves and buds of coniferous and broadleaf trees, such as Scots pine, Siberian larch, silver birch, and Eurasian 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 of cranberries, bog bilberries, myrtleberries, and other "Vaccinium" shrubs. They avoid the most extreme of desert and polar regions.

Reproduction

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 a lek. 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; in Russia, 150 is not uncommon and 200 have been recorded.

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 off the ground. A dent wide by 10–11 centimetres 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.

Where their range overlaps in similar biomes of other species, they are capable of hybridizing with the ringneck pheasant, western capercaillie, black-billed capercaillie, Siberian grouse, hazel grouse, and willow ptarmigan.