Habitat Selection by Pygmy Rabbits in Southeast Idaho

Habitat selection by pygmy rabbits (Brachylagus idahoensis) was investigated on three levels: landscape scale, habitat scale, and home range scale. A Geographic Information System (GIS) model was developed for the Idaho National Engineering and Environmental Laboratory (INEEL) and used to predict areas of pygmy rabbit non-use and areas of potentially appropriate habitat. Within predicted areas of potential habitat, vegetative and physiographic characteristics were analyzed to develop a Habitat Suitability Model. Areas of suitable pygmy rabbit habitat were characterized by greater cover and density of total shrubs and big sagebrush (Artemisia tridentata). Soil texture also differed between use and non-use areas. Use patterns were then investigated within active pygmy rabbit home ranges using radiotelemetry. Home range areas receiving disproportionate levels of use were identified and sampled for vegetative and physiographic differences. Pygmy rabbits most frequently utilized areas with structurally diverse stands of shrubs and predominantly sandy soils. Burrow areas provided the greatest shrub cover and had a higher forb component; high use areas also had a complex vegetal profile. Low use areas were characterized by less overall vertical complexity in the shrub community. Our results suggest that pygmy rabbits are extreme habitat specialists on all levels.