Habitat Selection by the Pygmy Rabbit (Brachylagus idahoensis) in Northeastern Utah

The pygmy rabbit (Brachylagus idahoensis), the world's smallest rabbit, has a limited distribution due to its year round dependence on sagebrush (Artemisia tridentata) for food and shelter. Due to accelerating habitat loss from fragmentation, development, and fire, understanding the pygmy rabbit's ecology has become increasingly important. In 2010, we initiated a study of the status of a pygmy rabbit population and its habitat requirements on U.S. Bureau of Land Management (BLM) land near Woodruff in northeastern Utah. We first observed and recorded the presence of the rabbit and its use of the area, and then measured sagebrush height, density, cover, and major and minor crown widths at active burrow and potential burrow sites. We also compared understory characteristics and soil texture at active, recently abandoned, and potential burrow sites. Pellets and sagebrush samples were also analyzed to determine dietary patterns. The height, as well as the major and minor crown widths of the sagebrush, and 2 cover measurements were significantly greater at active burrow sites than at potential burrow sites (P < 0.001). Total grass and forb biomass differed between the sites, with active burrow sites having higher total biomass in the spring compared to abandoned and potential burrow sites (P < 0.05) and higher total biomass in the fall compared to abandoned sites (P < 0.05). The principle component of the soil at all sites was sand, with small amounts of silt and clay. The pygmy rabbit's annual diet consisted of 80.7% sagebrush, and the sagebrush chosen for consumption was higher in crude protein and lower in fiber than nonforaged sagebrush. Our results suggest that maintaining stands of large mature sagebrush will provide pygmy rabbits in this area with preferred burrow and foraging sites that are vital to the persistence of populations in this region.