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Our surveys were conducted too early in the year to detect wintering bald eagles. Bald eagles have been observed along the Mokelumne River below the reservoir from October through April (Yee pers. comm.). Camanche Reservoir, 0.5 mile upstream of the project site, is surveyed annually for wintering bald eagles by the DFG, USFWS, EBMUD biologists and the Santa Cruz Predatory Bird Research Group. Because the survey is conducted on 1 day per year it provides only an estimate of bald eagles in the area. Since 1979, bald eagle populations at the reservoir have ranged from zero to 29 (Jurek pers. comm.). In January 1990, two adults and seven immature bald eagles were counted (Aulman pers. comm.). Eagles that use Camanche Reservoir probably also forage along the Mokelumne River downstream and could make regular use of the riparian open water, and upland habitats within the project site. Peregrine Falcon The peregrine falcon is a state-listed and federally listed endangered species. The falcon population has declined substantially in California and elsewhere because of pesticide contamination (California Department of Fish and Game 1988). Peregrine falcons occur near marshes, lakes, and rivers that support an abundance of birds. Inland and coastal marsh habitat are especially important in fall and winter when they attract large concentrations of waterbirds (California Department of Fish and Game 1980). The peregrine falcon is a winter visitor near the project site (Yee pers. comm.) and could occur in all habitat types at the project site. Our surveys were conducted too early in the year to detect migrant and wintering peregrine falcons. Swainson's Hawk The Swainson's hawk is listed as threatened in California. This migratory species was once a common breeder throughout the state, but a variety of habitat changes, including the conversion of native Central Valley native grasslands to agricultural, urban, and industrial development, caused an estimated 90% decline in the population (Bloom 1980). The Swainson's hawks'typical foraging habitat includes native grasslands and alfalfa or other hay ._ crops that provide suitable habitat for small mammals. Typical nesting habitat includes riparian forests, lone trees in open grasslands, oak groves, and roadside trees (Estep 1989). No records exist of Swainson's hawks nesting at the project site. Two raptor nests were observed in the oak woodlands during field surveys on September 6, 1990. One of these nests had red-tailed hawk young in the nest during spring 1990 (Larrouy pers. comm.). Eight active Swainson's hawk nests were observed in spring 1990 within 10 miles of the project site (Figure 4). One nest was about 0.5 mile north of the project site near Buena Vista Road (Yee pers. comm.). 19