Listed as Critically Endangered because of an observed population decline, estimated to be more than 80% over the last three generations, inferred from a decline in its area of occupancy, and from the effects of introduced predators, pollutants and pathogens. The generation length is assumed to be five years.
The habitat of this species includes sunny riverbanks, meadow streams, isolated pools and lake borders in the Sierra Nevada, and rocky stream courses in southern California. Seems to prefer sloping banks with rocks or vegetation to the water’s edge (Stebbins 1985). Seldom found away from water, but it may cross upland areas in moving between summer and winter habitats (Matthews and Pope 1999). Wintering sites include areas near shore under ledges and in deep underwater crevices (Matthews and Pope 1999). Probably does not tolerate timber extraction or cattle grazing, but these activities are rare within the range of this species.
Many thanks to IUCN for the information provided.