Site 300 Bat Survey Report

Abstract

A review of prior bat records in literature and museum collections for the five counties around Site 300 (Alameda, Contra Costa, San Joaquin, Santa Clara, and Stanislaus) identified 1038 specimens of 15 species. No roosting bats or bat sign indicating roosting were observed in examining samples of structures on Site 300 both day and night. Acoustic monitoring and visual observation detected seven to nine species, including three special status species -- the pallid bat, Antrozous pallidus, the western red bat, Lasiurus blossevillii and the Yuma myotis, Myotis yumanensis. An additional special status species, the long-legged myotis, Myotis volans was possibly present. As a consequence of the windy conditions typically encountered, no bats were caught in mist net sampling, though simultaneous acoustic monitoring demonstrated bats were present at those locations.