The Gunnison grouse, Gunnison sage-grouse or lesser sage-grouse (Centrocercus minimus) is a species of grouse endemic to the United States. It is similar to the closely related greater sage-grouse (Centrocercus urophasianus) in appearance, but about a third smaller in size, with much thicker plumes behind the head; it also has a less elaborate courtship dance. It is restricted in range to southwestern Colorado and extreme southeastern Utah, with the largest population residing in the Gunnison Basin region in Colorado. Despite being native to a country where the avifauna is relatively well known, it was overlooked until the 1990s due to the similarities with the sage grouse, and only described as a new species in 2000—making it the first new avian species to be described from the USA since the 19th century. The description of C. minimus as a separate species is supported by a molecular study of genetic variation, showing that gene flow between the large-bodied and the small-bodied birds is absent.
