The Amargosa vole (Microtus californicus scirpensis) is a highly specialized, critically endangered rodent subspecies that lives only in small patches in the otherwise inhospitable Death Valley; all of this habitat lies within the Bureau of Land Management’s Amargosa River Area of Critical Environmental Concern (ACEC) and Wild and Scenic River (WSR) management areas. The vole, which requires habitat dominated by bulrush (Schoenoplectus americanus) and a permanent water source, has one of the narrowest niche breadths and rarest available habitat of any North American mammal. Habitat availability and degradation have been the major causes of the species’ dramatic and ongoing decline. According to an early field journal of UC Berkeley Museum of Vertebrate Zoology’s Tracy Storer in 1917, the vole appeared to be “completely exterminated. There [were] no runways, even old ones, discernable, and none have been caught”. There was a successful collection of four individuals in 1939 at Tecopa Hot Springs but none again until the discovery of a small group of animals thought to have been extinct in 1973 . The Amargosa vole was listed as an endangered species by the state of California in 1980 and a critically endangered subspecies by the U.S Fish and Wildlife Service (FWS) in 1984. In its 1997 Recovery Plan, FWS cited “high threat and poor recovery prospects” as a justification for giving the Amargosa vole a high priority for recovery actions.
A collaborative project with the California Department of Fish and Wildlife, the US Fish and Wildlife Service, the Bureau of Land Management, UC Davis, and the UC Berkeley Museum of Vertebrate Zoology.