Great Basin Naturalist


Feeding sites of wintering sage grouse (Centrocercus urophasianus) were located, one each in stands of three subspecies of big sagebrush (Artemisia tridentata: ssp. tridentata, basin; ssp. vaseyana, mountain; and ssp. Wyomingensis, Wyoming). Evidences of differential use of plants within subspecies were observed. Whole leaves from fed-on and nonfed-on big sagebrush plants were examined for intrasubspecies chemical comparisons of crude protein, phosphorus, in vitro digestibility, and monoterpenoids. No significant differences were detected except for in vitro digestibility of Wyoming fed-on and nonfed-on big sagebrush and monoterpenoid content of basin big sagebrush. Nutritive content of all three subspecies was high, which may in part help to explain wintering sage grouse weight gains.