Pucrasia[note 1] Meleagris[note 1] Bonasa Tetrastes Centrocercus Dendragapus Tympanuchus Lagopus Falcipennis Canachites Tetrao Lyrurus and see text Tetraonidae Vigors, 1825 Tetraoninae Vigors, 1825 Grouse /ɡraʊs/ are a group of birds from the order Galliformes, in the family Phasianidae.

Grouse are presently assigned to the tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetraonidae), a classification supported by mitochondrial DNA sequence studies,[2] and applied by the American Ornithologists' Union,[3] ITIS,[4] International Ornithological Congress,[5] and others.

The traditional grouse (excluding turkeys) range in length from 31 to 95 cm (12 to 37+1⁄2 in), and in weight from 0.3 to 6.5 kg (3⁄4 to 14+1⁄4 lb).

If they are included, wild turkey toms are the largest grouse species, attaining lengths of 130 cm (50 in) and weighing up to 10 kg (22 lb).

Like many other galliforms, males often sport incredibly elaborate ornamentation, such as crests, fan-tails, and inflatable, brightly colored patches of bare skin.

Hatchlings eat mostly insects and other invertebrates, gradually reducing their proportion of animal food to adult levels.

Several of the forest-living species are notable for eating large quantities of conifer needles, which most other vertebrates refuse.

Their numbers may fall sharply in years of bad weather or high predator populations—significant grouse populations are a major food source for lynx, foxes, martens, and birds of prey.

Some subspecies, such as Attwater's prairie chicken and the Cantabrian capercaillie, and some national and regional populations are also in danger.

[9] The largest among the male grouse (commonly dubbed 'Biggrouse') attract the greatest numbers of females during their mating seasons.

[9] These differences in male behavior in mating systems account for the evolution of body size in grouse.

The male black grouse's tail feathers are a traditional ornament for hats in areas such as Scotland and the Alps.

Folk dances from the Alps to the North American prairies imitate the displays of lekking males.