Diana Hérens - The Grouse

A SHY BIRD, THE BLACK GROUSE RESIDES AT THE UPPER EDGE OF THE VALAIS FORESTS

In black grouse, the marked dimorphism (morphological difference between males and females of the same species) between the two sexes is revealed above all in the plumage. While the splendid black plumage with bluish highlights of the roosters is quite striking, the hens wear a camouflage plumage of pristine brown stripes all year round.

"THE BLACK KNIGHT'S DANCE

The black grouse parade is a unique and fascinating natural spectacle. Long before sunrise, in the depths of the night, the roosters gather on the traditional dance floor to a clatter of flapping wings. The first coos can soon be heard in the surrounding area. In an impressive parade, the roosters try to win the hens' favor by defending a small territory in the arena.

The older, higher-ranking roosters occupy the territories in the center of the arena. Tail feathers fanning, body leaning forward and chest puffed out, they coo as they survey their territory. At the borders of neighboring territories, they take on their rivals in ritual battles that sometimes turn into full-blown combat.

POPULATION SIZE AND DYNAMICS

Black grouse numbers are declining slightly in many places at the edge of their range. In contrast, their presence in the central Alps, as in the Valais, appears to be more stable, with a slight increase in the last two decades.
Annual fluctuations in numbers are essentially due to weather conditions at the start of the nesting season. While dry, warm weather guarantees successful nesting, cold, damp conditions mean that many chicks die. Changes in habitat and disturbance in particular have a negative impact on numbers. In Valais, the number of roosters is currently estimated at 2,100 birds.

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DID YOU KNOW?

During parades, roosters take on their rivals in ritual battles that sometimes turn into real fights.