The importance of sagebrush in the diet of adult greater sage-grouse is great; numerous studies have documented its year-round use. A Montana study, based on 299 crop samples, showed that 62% of total food volume of the year was sagebrush. Between December and February, it was the only food item found in all crops. Only between June and September did sagebrush constitute less than 60% of their diet. Sage grouse select sagebrush species differentially. Greater sage-grouse in Antelope Valley, California, browsed black sagebrush more frequently than the more common big sagebrush. The browse of black sagebrush is highly preferred by greater sage-grouse in Nevada. In southeastern Idaho, black sagebrush was preferred as forage.