Blackcock, Or Black Grouse (Tetrao Tetrix, Linn.), a highly prized game bird, of the family tetraonidce, very generally spread over the northern parts of Europe and Great Britain, particularly in the wild and wooded districts of Scotland. The male weighs sometimes as much as four pounds, and the female about two. In the male, the length to the end of the tail is about 23 inches, and the extent of wing 33 inches; bill an inch long, strong, and brownish black; the iris brown; over the eye a bare granulated skin of a scarlet color; the whole upper plumage of a steel-blue color, the scapulars and wings tinged with brown; the primaries brown, with brownish white shafts, the secondaries tipped with whitish, forming a bar across the wings, conspicuous in flight; the under wing coverts white, a few of them being visible when the wing is closed; the breast and sides brownish black, the abdominal feathers tipped with white; the legs and thighs dark brown, with grayish white specks, the former feathered to the toes; the lower tail coverts white, the upper brownish black; the tail, which is forked, with the lateral feathers curved outward, deep black.

The female is about 18 inches long and 31 inches in extent of wings; she resembles the other females of the family in her less brilliant markings; the general color of the plumage is ferruginous, mottled and barred with black above, and with dusky and brown bars on a paler ground below; the tail is nearly even at the end, straight, and variegated with ferruginous and black; the white about the secondaries and bend of the wing is much as in the male. The favorite abode of the blackcock is in the highlands and glens, among the hills clothed with a luxuriant growth of birch, hazel, willow, and alder, with an undergrowth of deep fern; here they find abundant food and shelter from the winter's cold and summer's sun. Their food consists of tender twigs, berries, heaths, and occasionally the seeds from the stubble fields. Their flight is heavy, straight, of moderate velocity, and capable of being protracted. They perch readily on trees, but the ordinary station is the ground, on which they repose at night.

The blackcocks are polygamous, and fight desperately for the females during April; having driven off all rivals, the male selects some eminence early in the morning, on which he struts, trailing his wings, swelling out his plumage and wattles over the eyes like a turkey cock; the females answer to his call and soon crowd around him. After the courting season the males associate together peaceably. The eggs are six to ten in number, of a dirty white color, with rusty spots, and are laid in a very rude nest on the ground, among the heaths; the young are reared entirely by the female, which they resemble in color. Their flesh is an excellent article of food. Foxes and rapacious birds kill great numbers of them.