Black-breasted hazel grouse

Black-breasted hazel grouse
Black-breasted hazel grouse ( Tetrastes sewerzowi )
Systematics
Class : Birds (aves) Order : Chicken birds (Galliformes) Family : Pheasants (Phasianidae) Subfamily : Grouse (Tetraoninae) Genre : Hazel Grouse ( Tetrastres ) Type : Black-breasted hazel grouse
Scientific name
Tetrastes sewerzowi
Prschewalsky , 1876

The black-breasted hazel grouse ( Tetrastes sewerzowi ), also known as the Chinese hazel grouse , is a species of the pheasant-like family. The species, which is closely related to the Eurasian hazel grouse , is found exclusively in mountain forests in central China. Together with the hazel grouse, the black grouse breast is one of the smallest members within the subfamily of the Grouse . There are two subspecies.

The species epithet honors the Russian natural scientist and explorer Nikolai Alexejewitsch Severzow .

Appearance

The black-breasted hazel grouse reaches a body length of 33 to 36 centimeters. The females are only slightly smaller than the males. Males weigh between 290 and 375 grams, while females weigh between 270 and 310 grams.

In appearance, the black-breasted hazel grouse is very similar to the hazel grouse. It is, however, a bit smaller and less feathery on the legs. The crest on the head is barely visible and is most noticeable in males during the breeding season. The beak is very short and black. The irises are dark brown.

In the adult male, the top of the head, ear patches and neck are reddish brown. The coat, back and torso are strikingly black and gray-brown stripes. The black spot on the throat and the thin white line behind the eyes are striking. The female is generally a little more dull in color. The black throat spot is less visible in her.

distribution and habitat

The black-breasted hazel grouse is endemic to central China, more than 1100 kilometers separate it from the easternmost distribution area of ​​the closely related hazel grouse.

The distribution area of ​​the black-breasted hazel grouse extends from central Ganzu to the south of Qinghai and the east of Tibet, the north-west of Yunnan and the north-west of Sichuan. It predominantly inhabits mountain forests, which are dominated by conifers. It prefers forests with a high population of birch and juniper. It reaches its highest altitude in the mountain forests of Tibet. It occurs here mainly in forests that are dominated by the Tibetan juniper . The habitat in this region is mainly forests that line rivers and, in addition to junipers, also have a dense population of pastures. The height distribution ranges from 2,400 to 4,700 meters. During the summer half-year it occasionally stays above the tree line and then mainly uses the slopes with rhododendrons .

Way of life

The way of life of the black-breasted hazel grouse is still largely unexplored. The black-breasted hazel grouse is believed to be strictly monogamous. The proportion of males in the population predominates and the individual males occupy territories that they usually keep occupied during the winter. Occasionally, however, small groups of four to 14 individuals form outside of the breeding season, which dissolve again in March. The courtship begins at the beginning of May, but the courtship behavior has so far been insufficiently investigated. During the courtship, the male is particularly noticeable because during this time it is courting the female with noticeable leaps in the air. You can clearly hear instrumental sounds that are formed with the wings. The nest is built on steep slopes on the root plates of trees or under fallen tree trunks. The clutch consists of five to eight eggs. The incubation period is 25 days.

Birch and willow play an important role in nutrition. For some regional populations it has been shown that in the winter from December to March, 80 percent of the food consists of the buds, pussy willow and twig ends of birch and willow trees. During the summer the food spectrum is larger and includes, for example, the seeds of knotweed .

Unlike the hazel grouse and the similarly closely related ruffed grouse, the black-breasted hazel grouse does not use snow chambers during the winter months. In the distribution area of ​​this species, the amount of precipitation in winter is low, so that the snow cover would usually not be sufficient for the construction of such chambers. Instead, black-breasted hazel grouse rear up in spruce and pine trees during the night and rest there close to the trunk. During the day they often sit on the snowpack - due to their altitude, the ambient temperature often reaches values ​​around 0 ° C even in winter thanks to the solar radiation.

Black-breasted hazel grouse are not shy of humans. Occasionally they tolerate an approach of up to 2.5 meters.

Systematics

genus

The genus Tetrastes is not recognized by some authors . Of these, both the hazel grouse and the black-breasted hazel grouse with the collar grouse belong to the genus Bonasus . These two genera are physiologically similar, but they differ greatly in their behavior. Hazel grouse form a monogamous pair bond. They lack the conspicuous courtship plumage or the conspicuous courtship actions for which the collar grouse is known.

Subspecies

Two subspecies are currently recognized:

• Tetrastes sewerzowi sewerzowi (Przewalsky, 1876): This subspecies occurs in the northern part of the range. In a southerly direction it extends to the Yellow River .
• Tetrastes sewerzowi secunda (Riley, 1925): This subspecies occurs in the south of the distribution area. It differs from the nominate form by a slightly darker body plumage and, above all, by the color of the tail feather. The black transverse bands of the tail feathers are smaller, they are separated from each other by five white narrow horizontal stripes. The nominate form, however, has six to seven white horizontal stripes.

In the ornithological collection of the Zoological Institute of the Russian Academy of Sciences there are skins of two female black-breasted hazel grouse, the plumage of which is different from other known skins. There is no reddish tinge of the head plumage and on the chest they have yellowish and not whitish spots. They are similar to western subspecies of the closely related hazel grouse . The two bellows were labeled by the Russian zoologist Pyotr Petrovich Sushkin , who died in 1928, whose notes indicate that he was considering the possibility that there is a third subspecies. However, this third subspecies has never been officially described scientifically and it is assumed that Pushkin wanted to collect further specimen copies. The two bellows come from the eastern edge of the range of the black-breasted hazel grouse.

Black-breasted hazel grouse

Unlike the hazel and collar grouse, the black-breasted hazel grouse is rarely hunted. The hunt therefore has no influence on the population size. More threats come from anthropogenic interference in the habitat. The forestry use of mountain forests, where black-breasted hazel grouse occur, has led to local extinctions of this species in some regions of China.

supporting documents

literature

• Steve Madge , Phil McGowan, and Guy M. Kirwan : Pheasants, Partridges and Grouse. A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails and Sandgrouse of the world. Christopher Helm, London 2002, ISBN 0-7136-3966-0 .
• Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 .

Single receipts

1. ^ WB Lockwood: The Oxford Dictionary of British Bird Names . Oxford University Press, 1993, ISBN 978-0-19-866196-2 .
2. ↑ Steve Madge, Phil McGowan and Guy M. Kirwan: Pheasants, Partridges and Grouse - A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails and Sandgrouse of the world , Christopher Helm, London 2002, ISBN 0-7136- 3966-0 , p. 377
3. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 74.
4. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 75.
5. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 77.
6. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 76.
7. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 76.
8. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 76.
9. ↑ see for example Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P.56
10. ↑ Steve Madge, Phil McGowan and Guy M. Kirwan: Pheasants, Partridges and Grouse - A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails and Sandgrouse of the world , Christopher Helm, London 2002, ISBN 0-7136- 3966-0 , p. 374
11. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 75.
12. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 75.
13. ^ Roald Potapov and Richard Sale: Grouse of the World . New Holland Publishers, London 2013, ISBN 978-1-78009-250-8 . P. 78.