Vegetative Characteristics and Size of Home Ranges Used by Pygmy Rabbits (Brachylagus idahoensis) during Winter

We determined sizes of home ranges for pygmy rabbits in southwestern Wyoming and characterized the vegetation within and outside those areas used during winters of 1993 and 1994. Seventy percent of pygmy rabbits used more than one core area within their home range. Habitats within home ranges had less low ground cover and a greater number of wider, taller Artemisia tridentata than did adjacent non-used areas. Pygmy rabbits selectively used dense and structurally diverse stands of A. t. tridentata, which also accumulated more snow than areas of low use. Structure and diversity of vegetation above the snow's surface declined as the season progressed and depths of snow increased. The sub-nivean environment provided access to a relatively constant supply of food and provided protection from predators and thermal extremes. We suggest that size of home ranges used by pygmy rabbits is influenced more by amount of vegetative cover than by forage.