San Joaquin River Rookery

Lying entirely within the San Luis Grasslands, this is the largest Ardeidae rookery in the San Joaquin Valley. Located on both sides of the river, up to 600 active nests have been counted in one year, with the bulk of the breeding population being great blue heron, Ardea herodias, the remainder, common egret, Casmerodius albus.

Vegetation in the area is oak savannah, with some riparian along the river. The rookery is located in the valley oaks, Quercus lobata.

Integrity: Use of this rookery is, in part, dependent on the amount of disturbance by man, primarily fishermen along the river, and the number of birds using the area varies from year to year. Another rookery has been established several miles away.

Use: Private

Ref: Page, Peter, 1971. Second Progress Report of the San Joaquin River Rookery Study. Mimeo., California Department of Fish & Game, Sacramento. 25 pp.

January 1977