Bat Surveys for SR 138 Road Widening

The Museum’s Bat Biologist Drew Stokes conducted focused bat surveys, identified appropriate mitigation measures, and oversaw implementation of these measures to reduce impacts to bat species on this Caltrans road-widening project between Interstate 15 and Phelan.

Surveys focused on assessing the suitability and determining the occupancy status of all potential bat roosting habitat within the project corridor, including bridges, wildlife under-crossings, and culverts. Relying on years of field observations and familiarity with methodology accepted by California Department of Fish and Wildlife (CDFW), Drew was able to provide detailed, feasible mitigation measures that were appropriate to the type of project and species of bat present within the project corridor.

Mitigation measures included the provision or identification of alternative temporary and permanent bat roosting habitat (i.e., bat houses, existing adjacent structures) and temporary bat exclusion procedures), with the goal of avoiding direct impacts to bats and co-occurring bird species while also minimizing potential delays in project construction.

The BioServices team worked closely with Caltrans and CDFW biologists to obtain background information and design appropriate and feasible mitigation measures. In addition, data on the efficacy of the bat houses used on this project were provided to and utilized by CDFW biologists to inform the design of mitigation measures for future projects.