Native to North America, the sharp-tailed grouse (Tympanuchus phasianellus) is famed for its elaborate courtship display, which is imitated by Native Americans during their traditional dances. It is a medium-sized grouse that is described as being chicken-like in appearance. The body of the sharp-tailed grouse is round and it has short legs. This species has a short crest on the head and the short tail has elongated central feathers, giving the tail a pointed or ‘sharp’ appearance. The sharp-tailed grouse is a cryptically coloured species, with its upperparts being barred with dark brown, black and buff. Its underparts are white, and the upper belly feathers display small, dark brown V-shaped marks. Both the male and female sharp-tailed grouse have a crescent-shaped, yellowish-orange comb over each eye. The feet of the sharp-tailed grouse are brownish-black and the bill is grey. The male sharp-tailed grouse is heavier than the female, and can be identified by the dark markings that run vertically along the central tail feathers, as well as by the pinkish to pale violet air sacs on the sides of the neck, which are inflated during courtship. Juveniles of this species are similar in appearance to the female, but are generally greyer and have a whiter throat. Although similar in appearance to the greater prairie chicken (Tympanuchus cupido) and the lesser prairie chicken (Tympanuchus pallidicinctus), the sharp-tailed grouse can be distinguished by the dark V-shaped marks on the underparts, the elongated central tail feathers, and the colour of the air sacs in the male. As part of the sharp-tailed grouse’s vocal array, both sexes produce a cluck when taking flight, sometimes described as a ‘whucker-whucker-whucker’ or ‘up-up-up’ sound. During courtship, the male produces a variety of vocalizations which have been variously described as hoots, cackles, squeaks, coos and gobbling noises. There are currently seven recognised subspecies of the sharp-tailed grouse, one of which is believed to be extinct. The northern forms are generally darker in colour and include the Alaska sharp-tailed grouse (Tympanuchus phasianellus caurus), the north-western sharp-tailed grouse (Tympanuchus phasianelluskennicotti), the northern sharp-tailed grouse (Tympanuchus phasianellus phasianellus) and the prairie sharp-tailed grouse (Tympanuchus phasianellus campestris). The paler southern forms are the Columbian sharp-tailed grouse (Tympanuchus phasianellus columbianus), plains sharp-tailed grouse(Tympanuchus phasianellus jamesi) and the extinct New Mexico sharp-tailed grouse (Tympanuchus phasianellus hueyi).