Bats Along the Tuolumne River

The natural ecology of bats has not been studied in-depth until recent technology made it possible. Following the lead of an on-going survey of bat populations at Poopenaut Valley in Yosemite National Park, a Petterson D40x auto-triggering time expansion recorder was used along the Tuolumne River for 8 nights. The intention of this project was to identify which species are present or absent at each study site. During the day, vegetation and insect surveys were performed; along with an assessment of the overall water conditions at each site. Habitat quality was assessed at each site, and was then used to find correlations of bat species richness at the end of the research excursion. The Petterson detector was linked to an H2 Zoom recorder, then the recordings were run through SonoBat software to identify different species. Only two species were successfully identified through recording take along Tuolumne River, due to excess noise also recorded and technical difficulties. Although the results were not as successful as hoped, these results still suggest that bats are affected by the changes occurring in the Tuolumne River.