All three are among the smaller grouse, from 40 to 43 cm (16 to 17 in) in length. They are found in North America in different types of prairies. In courtship display on leks, males make hooting sounds and dance with the head extended straight forward, the tail up, and colorful neck sacks inflated (shown in the photograph at upper right). Tympanuchus comes from Ancient Greek roots and means "holding a drum"; it refers to the membranous neck sacks and the drum-like call of the Greater Prairie-chicken.
The two prairie chickens are particularly closely related and look extremely similar.
The extinct Heath Hen of the American east coast, usually considered a subspecies of the Greater Prairie-Chicken, has been considered a separate species.