Forage Diversity and Dietary Selection by Wintering Mule Deer

Abstract

During a 30-day grazing trial, six mule deer (Odocoileus hemionus hemionus) at pasture altered their food selection significantly as availability of forage changed. At the beginning of the trial when forbs and grasses were abundant, they comprised better than 50% of the diet; but by the end of the trial when these preferred forages were less abundant, grass and forb declined. Shrub use increased and forb and grass use decreased as snow depths increased. Results support the conjecture that big sagebrush (Artemisia tridentata wyomingensis) in excess of 30% in the diet is detrimental to mule deer nutritional health.