Black grouse (Tetrao tetrix)
|Size||Male length: 55 cm (2)|
Female length: 40 cm (2)
The black grouse is classified as Least Concern (LC) on the IUCN Red List (1). It is listed on the red list of Birds of Conservation Concern in the UK. Protected under the Game Acts (close season 11 December-19 August, Annex II/2 of the EC Birds Directive and Appendix III of the Bern Convention (3).
The black grouse (Tetrao tetrix), also known as 'blackgame' (4) is one of Britain's most striking gamebirds (5). The male has glossy blue-black plumage, white wing bars, a lyre shaped tail and white under-tail coverts. Females are brown with pale wing bars, and both sexes have red wattles above the eye. Displaying males produce a bubbling pigeon-like rroo-ooo sound known as 'rookooing'(2).
Found in fragmented areas throughout northern and central Europe, almost reaching the Pacific coast (6). In Britain the black grouse is found in Scotland, the north of England, and in scattered areas of Wales (7).
In Britain the black grouse occupies a mosaic of woodland and scrub with an understory of heather (Caluna vulgaris) and bilberry (Vaccinium myrtilus). They may also inhabit rough grazing land, hay meadows and forestry plantations, as their preferred habitat is now scarce (6).
The black grouse has a diet that varies throughout the year, but the shoots, buds and fruit of bilberry and heather form staples. In the first three weeks of life, the young depend solely on invertebrates (6).
Black grouse males gather at traditional sites in the morning to perform complex displays known as 'leks'. During the display, the males raise their tails and inflate their necks whilst producing the soft 'rookooing' call. Females sit in vegetation close to the lek to watch the performance. Males with the best display obtain dominance and gain access to more females (6). In early May between 6 and 11 yellow eggs are laid in a moss-lined scrape in the ground concealed by vegetation. The young hatch 25 days later, and are fully independent after a further two to three months (7).
Between 1968-72 and 1988-91, the range of the black grouse declined by 28 percent. Numbers also declined; in 1990 there were an estimated 25,000 lekking males in the UK, this had fallen to just 6,510 by 1996. This huge decline is due to a number of factors, including the loss of important plant food sources due to over-grazing and agricultural intensification. In order to prevent over-grazing in woodlands, high fences are often erected to exclude deer. Unfortunately, adult and juvenile black grouse are often killed after colliding with these fences. In addition to these threats, predation by foxes and crows may limit the population in some areas (7).
On many nature reserves supporting black grouse, grazing has been reduced, fences removed and predators have been controlled. These measures will help the black grouse and the capercaillie (Tetrao urogallus). However, similar measures must be applied in the wider unprotected landscape in order to safeguard the species (6); this is more of a challenge, one which the RSPB, the Forestry Commission, English Nature, Countryside Council for Wales, Scottish Natural Heritage and the Game Conservancy Trust are tackling in various recovery programmes (3). The black grouse is a priority species under the UK Biodiversity Action Plan. The plan aims to promote a sustained recovery of the species over the next 20 years (3).
For more information on the black grouse and other bird species:
Information authenticated by the RSPB:
- Invertebrates: animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones), echinoderms, and others.
- Lek mating system: system of mating in which males display collectively in an area known as a lek. Males compete for the best sites within the lek and females then choose whom to mate with on the basis of the display.
IUCN Red List (April, 2011)
- Peterson, R.T., Mountfort, G., Hollom. (1993) Collins Field Guide. Birds of Britain and Europe. Harper Collins, London.
UK Biodiversity (November 2001)
- 4) Greenoak, F. (1997) British birds, their folklore, names and literature. Christopher Helm A&C Black, London.
Game Conservancy Trust (November 2001)
RSPB (November 2001)
- Battern, L. A., Bibby, C. J., Clement, P., Elliott, G. D. and Porter, R.F. (1990) Red Data Birds in Britain. T & A.D. Poyser, London.