Bats in the south coast ecoregion: status, conservation issues, and research needs

Abstract

California’s bat fauna is one of the most diverse in the United States. Of the 25 species of bats in the state, 24 have been detected in the south coast ecoregion. Many of these species appear to have experienced population declines in the ecoregion, and 16 are officially recognized as sensitive (including one endangered) by wildlife regulatory agencies. Data from recent field survey work conducted by bat researchers were compiled in order to provide a tentative assessment of the current status of bats within the south coast ecoregion. These data suggest that the pallid bat (Antrozous pallidus), Townsend’s big-eared bat (Corynorhinus townsendii), and California leaf-nosed bat (Macrotus californicus) have experienced population declines and could be seriously threatened, particularly at lower elevations. This may also be true for some of the region’s other bat species, such as the western red bat (Lasiurus blossevillii), but additional research is needed. The Yuma myotis (Myotis yumanensis), Mexican free-tailed bat (Tadarida brasiliensis), and big brown bat (Eptesicus fuscus) were frequently encountered in both Krutzsch’s (1948) and recent field inventories, so they appear to remain relatively common at this time. The major threat to bats in the ecoregion is the loss of habitat (especially riparian and oak woodland habitats) due to urban expansion as well as extermination or disturbance of bat colonies. Characterization of species-specific distribution and seasonal habitat use patterns is needed so that land managers can address both foraging and roosting habitat requirements from a landscape perspective. Research is also needed regarding the effects of urbanization, insect control, tree/snag management, bat exclusions, mine closures, and recreational activities, specifically rock-climbing, on bat populations.

Parent Publication

• Planning for biodiversity: bringing research and management together; Proceedings of a Symposium for the South Coast Ecoregion

Citation

Miner, Karen L.; Stokes, Drew C. 2005. Bats in the south coast ecoregion: status, conservation issues, and research needs. In: Kus, Barbara E., and Beyers, Jan L., technical coordinators. Planning for Biodiversity: Bringing Research and Management Together. Gen. Tech. Rep. PSW-GTR-195. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 211-227