Most of the remaining range, including population strongholds in eastern Alameda and Contra Costa counties and areas south and west of Millerton Lake in Madera and Fresno counties, is imminently threatened by urban development, conversion of natural habitat to agriculture, introduction of exotic predatory animals (bullfrogs, crayfish, various fishes) that temporarily may occupy salamander breeding habitat, and/or other anthropogenic factors (e.g., rodent control programs, vehicle-related mortality). Reduced ground squirrel populations might reduce the availability of burrows, which are important habitats during the dry season. The use of pesticides for mosquito abatement might reduce food resources for salamanders. Introduction of non-native tiger salamanders might harm populations through hybridization and/or competition. Contaminated runoff from roads might adversely affect salamanders in breeding sites. Localities in the Diablo Range, inner Coast Ranges, and Sierra Nevada foothills are not significantly threatened at present, and there are still a relatively large number of remaining breeding localities. In Santa Barbara County, plans to convert remaining breeding areas from grazing to intensive agriculture are being developed and implemented (USFWS 2000). Five of the six existing habitat complexes supporting this population suffered moderate to severe levels of habitat destruction or degradation between 1996 and 2000 (USFWS 2000). See USFWS (2000) for further information on threats to the Santa Barbara County population.