Caucasian grouse (Tetrao mlokosiewiczi)

Also known as: Caucasian black grouse
GenusTetrao (1)
SizeMale head-body length: 50 - 55 cm (2)
Female head-body length: 37 - 42 cm (2)
Male weight: 820 - 1005 g (3)
Female weight: 750 - 784 g (3)

The Caucasian grouse is classified as Near Threatened (NT) on the IUCN Red List (1).

The Caucasian grouse (Tetrao mlokosiewiczi) is one of the most elusive and least studied of all grouse species (4).

The adult male Caucasian grouse has black plumage, with a long, deeply forked, downward-curving tail and distinctive red eyebrow wattles (2) (3). The undersides of the wings are white, and can be seen in flight (5). This species is very similar in appearance to the black grouse (Tetrao tetrix), but the Caucasian grouse lacks a white wing-bar and white undertail-coverts (2) (3).

The female Caucasian grouse has grey-brown plumage, with fine, dark barring on the underparts and an almost square-ended tail (3). As with male, the female Caucasian grouse is similar in appearance to the black grouse, but has darker cheek patches, paler eyebrow stripes and finer barring (2).

The juvenile male Caucasian grouse is very similar in appearance to the female, with grey-brown plumage (3).

The Caucasian grouse is one of only three bird species endemic to the Greater and Lesser Caucasus mountain region (6).

The Caucasian grouse population is patchily distributed across six countries: Russia, Georgia, Turkey, Armenia, Azerbaijan and Iran (6). The majority of this species’ range is in Russia and Georgia (4).

The elusive Caucasian grouse inhabits treetops in the transition zone between upper montane forests and lower sub-alpine meadows, at elevations between 1,300 and 3,300 metres (7).

Open terrain close to the treeline also forms an important part of this birds’ habitat, and is used for leks in spring and feeding throughout the summer (8).

The Caucasian grouse typically forages just after daybreak and towards dusk (3). In winter, a variety of plants form the basis of its diet, including birch buds and catkins, juniper fruits, various shrub shoots and rosehips. In other seasons, the Caucasian grouse has a more diverse diet, feeding on a multitude of herbs and grasses, as well as seasonally available buds, leaves and fruit (4) (8). Arthropods are a diet staple of chicks in the first two weeks after hatching, but are rarely taken by adults (3).

The traditional leks of the male Caucasian grouse occur in spring and are carried out in open habitat away from the treeline (4). The display involves short bursts of fast-paced running, alternated with upward jumping and periods of standing still. When the males come within four to five metres of each other, they elevate their long tails and begin to walk parallel to one another (9). Although the male Caucasian grouse is almost mute, a soft whistling sound is made by the wings during display (2).

Unlike the male Caucasian grouse, the female is not mute and has a cackling call (2). In May, the female lays between two and ten eggs at a time, in a shallow ground scrape concealed by vegetation. The eggs are incubated for 20 to 25 days, and the chicks are able to fly 10 to 14 days after hatching (3).

Disturbance at the Caucasian grouse’s nesting and lekking sites, largely due to deforestation, harvesting for wheat and grass, and overgrazing, have affected this species’ reproductive success (4). Habitat degradation has also fragmented the already limited distribution of the grouse, resulting in small, isolated populations. Small populations have an increased probability of extinction, due to chance events or the loss of genetic variation caused by inbreeding (10).

Illegal hunting is also an increasing threat, particularly in the Lesser Caucasus area, where road development has made grouse habitat more accessible (1).

Research, large-scale conservation projects and educational activities are underway in Georgia and Turkey, to improve knowledge and promote awareness of the Caucasian grouse (6). Population surveys for the grouse have also begun in Azerbaijan, and a captive breeding programme is being developed in Armenia (6).

Continued fieldwork has been recommended to determine the current population status of the Caucasian grouse, identify potential threats and develop mitigation measures (1).

Learn more about the conservation of this species and other birds:

Find out about conservation in the Caucasus:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. IUCN Red List (June, 2011)
  2. Mullarney, K., Svensson, L., Zetterstrom, D. and Grant, P.J. (2009) Collins Bird Guide Second Edition. HarperCollins Publishers Ltd, London.
  3. del Hoyo, J., Elliott, A., Sargatal, J. and Cabot, J. (1994) Handbook of the Birds of the World. Volume 2: New World Vultures to Guineafowl. Lynx Edicions, Barcelona.
  4. Storch, I. (2000) Grouse Status Survey and Conservation Action Plan 2000-2004. WPA/Birdlife/SSC Grouse Specialist Group,IUCN, Gland, Switzerland and Cambridge, UK and the World Pheasant Association, Reading, UK.
  5. Firouz, E. (2005) The Complete Fauna of Iran. L.B. Tauris and Co., London.
  6. BirdLife International (June, 2011)
  7. Baskaya, S. (2003) Distribution and principal threats to Caucasian black grouse Tetrao mlokosiewiczi in the Eastern Karadeniz Mountains in Turkey. Wildlife Biology, 9(4): 377-383.
  8. Etzold, J. (2005) Analyses of vegetation and human impacts in the habitat of the Caucasian Black Grouse Tetrao mlokosiewiczi in the Greater Caucasus/Azerbaijan. Archiv fϋr Naturschutz und Landschaftsforschung, 4: 7-37.
  9. Masoud, M. and Fanid, L.E. (2006) A Study of Caucasian black grouse Tetrao mlokosiewiczi population dispersion confined in Iran. Grouse News - Newsletter of the WPA/BirdLife/IUCN/SSC Grouse Specialist Group, 31: 5-8.
  10. Frankham, R., Ballou, J.D. and Briscoe, D.A. (2004) A Primer of Conservation Genetics. Cambridge University Press, Cambridge.