Also distinctly American are the Sharp-tailed Grouse (Pediocates), so called from the fact that the tail is graduated with the middle pair of feathers projecting much beyond the others ; there are no elongated tufts or air-sacs on the sides of the neck. They are rather large birds, though smaller than the Prairie Hen, irregularly spotted and barred above with black and brownish, and white beneath, where there are often V-shaped markings of dusky. Three forms are known, the true Sharp-tailed Grouse (P. phasianellus), a very dark colored bird inhabiting the wooded districts and prairie borders of the interior of British America; the Columbian Sharp-tailed Grouse (P. p. columbianus), a lighter colored form of the grass-covered plains of the northwestern United States ; and the Prairie Sharp-tailed Grouse (P. p. campestris), also a light-colored but more reddish bird, inhabiting the Great Plains. Similar to these, but differing in having the tail longer instead of shorter than the wings, is the Sage Grouse (Centrocercus urophasianus), which next to the Wild Turkey is the largest of the North American game birds. It inhabits the sage-brush plains and table-lands of the western parts of the United States, feeding on the leaves of the sage-brush (Artemisia), berries, fruits, and occasional insects.
The two remaining genera of Grouse one in North America and the other in the northern portions of the Old World may be known at once from those previously mentioned by having the lower part of the tarsus naked. The former contains the Ruffed Grouse (Bonasa), which are further distinguished by a ruffed frill of broad, soft feathers on each side of the neck, and a tail composed of eighteen feathers, while the latter embraces the Hazel Hens (Tetrastes) that are without the frill on the sides of the neck and have a tail of sixteen feathers.