Also found in: Dictionary.
(Tetrastes bonasia), a bird of the family Tetraonidae of the order Galliformes. The hazel hen is 35–37 cm long and weighs 350–500 g. The wings are short and blunt. The hazel hen takes wing noisily and flies only short distances. The toes and the lower part of the metatarsus are naked. The plumage is reddish gray with mottling; the coloration of hazel hens living in Siberia is a purer gray.
The hazel hen is distributed in Europe and Asia. In the USSR it is found in the forest zone from the Carpathians to Sakhalin; it is not encountered in the Caucasus or Kamchatka. Hazel hens are sedentary birds, making only short food-seeking journeys. They live in pairs in humid dense coniferous (spruce and fir) and mixed forests. The birds nest on the ground. A clutch contains six to ten eggs, which are incubated by the female for about three weeks. Six weeks after hatching, the young reach adult size. They feed at first on insects and later on plant substances. In the winter the hazel hen feeds on the catkins of birch and alder trees; it spends the night in the snow. In the summer the bird feeds principally on berries, seeds, insects, and the green parts of plants. The hazel hen is a valuable commercial bird.