Black grouse

The black grouse , also called small cock of heather ( Lyrurus tetrix ) is a sedentary bird, symbol of the European Alps.

He is regarded as a species relic of the diluvial periods, because its distribution is Scandinavian and boréo-mountain.

Classification

The black grouse belongs to the family of the Tétraonidés (that is to say 18 species), to the kind Lyrurus (also gathering the Tétras of the Caucasus) and to the species Lyrurus tetrix . Because of systematic proximity of the species with the capercaillie, certain authors include it in the kind Tetrao . It is into 1758 that Linné, large zoologist and botanist, scientifically described for the first time this species.

There exist 6 subspecies:

Lyrurus tetrix baikalensis (Lorenz, 1911) - Area of the lake Baïkal, Mongolia of North, Basin of the Love.
Lyrurus tetrix britannicus (Witherby & Lonnberg, 1913) - Great Britain (Scotland, Ireland…).
Lyrurus tetrix mongolicus (Lönnberg, 1904) - Mongolia, China of the North-West.
Lyrurus tetrix tetrix (Linnaeus, 1758) - the Alps, Central Europe, Scandinavia, Russia
Lyrurus tetrix ussuriensis (Kohts, 1911) - Mandchourie, China.
Lyrurus tetrix viridanus (Lorenz, 1891) - Russia, Kazakstan

Description

Size: Female (or hen) 50-53 cm; Male (or cock): 60 cm
Scale: 65 to 80 cm
Weight: Hen: 700 to 850 G; Adult cock: 1 100 to 1.500 G
Longevity: 6 to approximately 9 years
Male: black with blue reflections, its wings are brown-black with a small white bar. The lower part of the wings and the tail is white. The tail finishes in the shape of quadrant from where its name. The legs short and are enplumées. Above the eye, a red caruncle, by variable size, very developed at spring, surmounts a nozzle runs.
Female: Delivered brown and reddish barred of black, white and gray. The tail slightly fourchue.
the fingers of the legs have a fringe of scales corneas which act like rackets and avoid with the bird being inserted in fresh snow.
Manners: Sedentary, polygamous and sociable bird all the year.
food Mode: Mainly vegetarian, nourishing sheets, buds, seeds, flowers and bays, it supplements his food with insects, spiders and invertebrates.
Predatory natural: Around S, Fox S, Wild boar S, Mustélidé S, crow S and Black and white S for brooded and eggs.

Reproduction

The black grouse is especially famous for its spring bridal parades. The males find themselves every year, in April, March, May and at the beginning of June on the spaces released from trees, plates or peat bogs called “places of songs”. In the center of this site the arena is, where the cocks parade, sing, measure themselves; the gestures and the paces have a whole a quite precise significance: provocation, domination…

The hens, they, rove here and there, from one place to another, and choose each one their future partner who is always the male dominating; they end up being coupled towards mid-May. At the end of May, the hens already start to lay (from 3 to 10 eggs), then to brood; 26 days after the big shot of last egg, the young chicks are born. The small ones are nidifuges, but remain accompanied by their mothers until the autumn, where they disperse.

The females lay with same the ground, in a cluster of brushwood, often hidden in a thicket where they are then very vulnerable.

Habitat and distribution

Geographical distribution

In France: Present on most of the alpine solid mass (of Chablais to the VAr), they are nevertheless vulnerable because of tourist installation; much more locally in the Ardennes, they are there in process of extinction.

In Europe: Absent from the Iberian peninsula, the small cock of heather lives Great Britain, the Alps, Scandinavia, Eastern Europe, but also Germany, Belgium, the Netherlands and Denmark where the populations are isolated but testify to a glorious past.

In the World: The grouse is present only in Eurasia, where it populates most of Russia, the north of Kazakstan, Mongolia and China.

Habitat

In construction

Its vital domain in the Alps

The black grouse needs a vital domain of at least 3.000 hectares, including/understanding forests of conifers with clearings and the peat bogs; one finds it up to 2.300 m of altitude, limits higher trees, zone of the Rhododendron S and green alders. It very related to the presence of shrubs of the family of is éricacées (Airelle, Myrtille, Canneberge, Bruyère S, Callune…). For a long time, the man, thanks to the exploitation of the mountain pastures, supported ideal living conditions to the black grouse

Traditionally, the populations of black grouse are very sensitive to the deforestation and the development of the extensive pasture which destroys the low vegetation essential to the bird. Today, the threats are thus the parcelling out and the destruction of the habitat, abusive hunting but especially disturbances, because its vital Espace is often partly integrated in the skiables fields of the stations, which splits up its habitat. Countings carried out showed a density of 0,95 black grouse, for 100 hectares, in the sectors of the ski stations, whereas generally it is of 3,25 in the virgin zones.

Often victim of collisions mortals with the cables of ski lifts, its principal enemy is, the winter, the skier out-track, the amateur of fresh duster, and the summer, the hiker. Indeed, as of the cold first of the autumn, the black grouse gather to survive and seek zones of wintering where snow remains powdery. As of the first snows, it hide in a kind of igloo while watching for the possible predatory ones. It can spend the whole night and a good part of the day in this shelter if the weather is. It saves its energy thus.

With each disturbance, the black grouse flee and dig a new gallery in snow; thus the practice of the ski out-track, multiplies the risks of disturbance, which seriously compromises the energy balance of the black grouse, by stopping its phases of rest, by creating stress and while obliging with the dispersion of the groups. The summer, the bird is too often disturbed by the hundreds of hikers and in particular the dogs left in freedom; one of the conditions of its survival is then the existence of a high vegetation on the ground.

In certain areas of the Alps of measurements started to be taken, for the safeguard of the black grouse, such:

safeguarding of virgin zones of all human activities;
prohibition of the zones of wintering to the skiers out-track;
in certain zones, limitation of the passage of the hikers to the marked out paths and prohibition of the dogs in freedom;
in certain zones, delayed-action of the rise of the herds in mountain pasture;
installation on the cables of spirals or stoppers, goods visible by the birds, in order to limit the collisions.

Legal statute

Population estimated in Europe: 325.000 to 740.000 couples.

The black grouse is one of the species mentioned with appendix 1 of directive 79/409 of the EEC, which implies to take " conservation measures special concerning their habitat, in order to ensure their survival and their reproduction in their surface of distribution".

The British subspecies remains classified like game, which makes it possible to drive out it and to make preserves of them.

See too

Taxonomic references

External bonds

Black grouse and alpine grouse: leave them quiet!
Grouse in Wallonia

Be-X-old: Цецярук

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