© Copyright: Images: Jari Peltomäki, M. & W. von Wright: Svenska fåglar (Kansalliskirjasto, The National Library of Finland). Recording: Jan-Erik Bruun. All rights reserved.
- Name also: Eurasian Black Grouse
- Latin synonym: Tetrao tetrix
- Family: Pheasants and partridges – Phasianidae
Subfamily: Grouse – Tetraoninae
- Appearance: Males large and dark in colouring, with lyre-shaped tails. Females brownish, medium-sized grouse. Both sexes have pale wing stripes.
- Size: Length 40–58 cm, wingspan 65–80 cm, weight 1.2–1.3 kg (male), 0.9–1 kg (female). Juveniles are lighter. Adults’ weight tends to increase progressively northwards in Finland.
- Nest: In a depression dug out by the female, lined with straw, dry leaves, pine and spruce twigs with needles, feathers etc. Well concealed, often beneath a tree or bush or among dwarf shrubs.
- Breeding: 8–10 eggs most often laid in May, incubated by female for 23–29 days. Fledglings learn to fly within 7–14 days.
- Occurrence: Can thrive in all kinds of forest habitat, but particularly in well-lit sparse woodland and near the margins of open areas such as bogs, felled forest areas and farmland, but also near shores and on islands. In winter dependent on middle-aged birch stands. Finland’s Black Grouse population is today estimated at 350,000–500,000 pairs, but earlier their numbers were much higher. Likely reasons for their decline include the loss of birch stands, the impacts of forest management on the sites they use for shelter, and increases in the numbers of small mammal predators, notably racoon dogs.
- Migration: Sedentary, but some birds (probably juveniles) may roam for distances of 10–25 km in autumn and spring.
- Diet: Varies seasonally. In summer, buds, shoots and seeds; in autumn, berries and grain; in winter, birch and alder catkins, young pine cones, and buds on deciduous trees.
- Calls: During the mating season cooing and tuneful babbling calls, which form a continuous chorus when performed by several birds in the same courtship display site. These calls are occasionally interrupted by a loud, harsh whistle.
Male Black Grouse are easily recognisable large, bluish black grouse with distinctive lyre-shaped tails. In flight a broad white wing stripe is prominent on their otherwise dark grown wings, and their tails appear long. They have a red wattle-like marking just over each eye. Females and juveniles resemble female Capercaillies, but are smaller and have more obvious whitish wing stripes, slightly forked tails, and yellowish brown crosswise streaks on their necks. Black Grouse’s legs are covered with feathers, and their toes are dark brown. Their beaks are black and their irises are dark brown.
Males gather in spring at collective courtship display sights known as leks, where females also gather to choose a mate. Black Grouse leks are typically located in open areas such as bogs, undisturbed fields and frozen ponds or lakes.
The Black Grouse is Finland’s most numerous grouse, and it is a game bird, widely hunted in the autumn.