The Greater Sage-Grouse, Centrocercus urophasianus, is also known as the Sage-Hen and the Sage-Chicken.
The largest of the North American grouse, the male is 25 to 30 inches in length and may weigh up to seven pounds. The female is smaller, averaging 20 inches in length and slightly less than three pounds. It is a grayish-brown bird with a dark belly, and long and pointed tail feathers. The feet are feathered to the toes. The throat of the male is black, bordered with white at the rear. Yellow air sacs, covered with short, stiff, scale-like white feathers, are found on each side of the neck. The female has the same general appearance but lacks the air sacs and has a white throat.
These birds inhabit sagebrush plains, foothills, and mountain valleys. Sagebrush is the predominant plant of quality habitat. Where there is no sagebrush, there are no Sage-Grouse. A good understory of grasses and forbs, and associated wet meadow areas, are essential for optimum habitat.
Male Sage-Grouse gather on traditional "strutting grounds" during March and April and put on a spectacular courtship performance - strutting with tails erect and spread, and air sacs inflated. Females visit the grounds during the first part of April. A few dominant cocks do most of the mating. Nesting begins in April. Nests are shallow depressions lined with grass or twigs and are usually located under sagebrush. The female lays from five to nine eggs, which hatch after 25 days of incubation.
The principal winter food item is sagebrush leaves. During summer, the fruiting heads of sagebrush, leaves and flower heads of clovers, dandelions, grasses and other plants are taken. Insects are also taken during the summer. Sage-Grouse are the only North American grouse which do not have a muscular grinding gizzard.
Sage-Grouse were abundant in pioneer times, but sagebrush eradication and intensive use of lands by domestic livestock have reduced their numbers. Sage-Grouse range is declining in Utah in both quantity and quality. Indiscriminate spraying of sagebrush, cropland conversion, and over-grazing of mountain meadows are the causes. The result has been an overall decline in Sage-Grouse populations. Sage-Grouse range has declined 50 percent from historical times. Greater Sage-Grouse are native to Utah and are listed as a sensitive species by the Utah Division of Wildlife Resources.