THE COOPERATIVE BLACK GROUSE COUNT

Drygały Forest District (RDSF in Białystkok) has already counted the black grouses. Birds were observed within Natura 2000 SPA “Ostoja Poligon Orzysz”.
05.06.2017 | EWA NOWACKA, DRYGAŁY FOREST DISTRICT

Drygały Forest District (RDSF in Białystkok) has already counted the black grouses. Birds were observed within Natura 2000 SPA “Ostoja Poligon Orzysz”.

These birds, which are under strict protection, were counted in their breeding grounds by foresters and the workers of Regional Directorate for Environmental Protection in Olsztyn. About 20 males displaying courtship were observed during the inventory.

One of the most numerous population of these species in the northwest part of Poland occurs in  Drygały Forest District (RDSF in Białystok). The inventory of black grouse is performed each year during its mating season, also known as the courtship display.

At the same time at down, black grouse cocks are observed during their courtship display in 10 marked leks. It’s a fantastic “dance and vocal performance”. Movements and sounds of mating black grouse cocks are intended to scare rivals and impress hens , which fly into the courtship areas at sunrise.

Black grouse is a beautiful bird from Phasianidae family, about the size of chicken. It is characterized by a distinct sexual dimorphism. Males, called also cocks, are bigger and have more colourful plumage than females which are called hens. Black grouse female may lay 7 - 11 eggs. Interestingly, chicks are able to fly in about two weeks after hatching.

One year old cocks have more green colouring. Older cocks have black colouring with blue gloss and wattles above their brows are swelling with intense red colour. . Adult males taking part in courtship display have well-developed outer rectrices.

Black grouse (Tetrao tetrix) is one of the most endangered bird species in Poland. In 1960s, however, this species occurred in the whole area of Poland, and its population oscillated between 10-20 thousand individuals. Unfortunately, in 1970s the population began to  decrease.

In Poland the population of these characteristic grouses is under species and zonal protection. Moreover, it is recorded in Polish Red Data Book of Animals  as the species of  a very high risk of extinction. Current estimates show that its population amounts approx. 600 individuals.