Status of the Pygmy Rabbit (Brachylagus idahoensis) in Washington

The pygmy rabbit (Brachylagus idahoensis) is the smallest rabbit in North America. It is found throughout much of the sagebrush-dominated area of the Great Basin. This includes portions of Oregon, California, Nevada, Utah, Idaho, Montana, Wyoming, and Washington. Washington populations are disjunct from the core of the species' range, apparently separated for thousands of years. The pygmy rabbit is the only rabbit in North America that digs its own burrows. It is also uniquely dependent upon sagebrush, which comprises up to 99% of its diet. Dense sagebrush and relatively deep, loose soil are important characteristics of pygmy rabbit habitat.

Paleontological evidence shows that the species had a broader distribution in Washington thousands of years ago. However, within the past 7S years, pygmy rabbits have been lost from most of their historically documented range in Washington. Museum specimen records and reliable sight records show that pygmy rabbits formerly occupied sagebrush habitat in five Washington counties: Benton, Adams, Grant, Lincoln, and Douglas. Currently, pygmy rabbits are known to survive in live isolated fragments of suitable habitat, all in Douglas County.

In Washington, most former pygmy rabbit habitat has been altered such that it no longer can support populations. Crops are grown in most places where soils are sufficiently deep. In some areas where sagebrush remains, intensive grazing reduces the suitability of the habitat by breaking off sagebrush and opening up the shrub canopy. Range fires destroy habitat and extirpate local populations. Of the five populations known to remain in Washington, the largest may be comprised of fewer than 150 rabbits. The other four populations are significantly smaller.

The pygmy rabbit is listed as a threatened species by the Washington Wildlife Commission. It is listed as a Candidate Category 2 species by the U.S. Fish and Wildlife Service. The Washington Department of Wildlife, Soil Conservation Service, Washington Department of Natural Resources, and grazing permittees are involved in cooperative efforts to manage grazing and other activities to provide for pygmy rabbit habitat and populations at the primary Washington site. The Bonneville Power Administration is providing funding for conservation easements, management agreements, acquisition, or enhancement of pygmy rabbit habitat to mitigate for habitat losses from hydropower development.

Despite these efforts, pygmy rabbit numbers are too few and their distribution too limited to be considered secure. Any of a variety of catastrophic events such as fire, disease, flooding, or intense predation, could result in complete loss of the species from Washington. It is recommended that the pygmy rabbit be reclassified from a threatened species to an endangered species in Washington.