Author(s): Ammon Miles, Anthony Kemp, Connor Baty
Mentor(s): Geoffrey D. Smith, Zhenyu Jin
Institution UTech
We studied bat species in Washington County, Utah to determine factors influencing activity and species richness from September 17 to November 17, 2024. For data collection, we used three different Wildlife Acoustic’s Echo Meter Touch 2 Pro were used 30 minutes after sunset for 30 minutes. Nine different sites were visited once per week and temperature and wind speed were recorded at each session. We recorded the total calls then identified them using the Echo Meter app. We found that the diversity over time did not significantly change, with the average being 3.5 species a session. We found the most prevalent bat species to be Canyon Bat (Parastrellus hesperus), Mexican Free-tailed Bat (Tadarida brasiliensis), Silver-haired Bat (Lasionycteris noctivagans), then Big Free-tailed Bat (Nyctinomops macrotis) with those top four species comprising 85.3% of bat calls identified. We found that bat activity did change over time, with the average changing from 42 calls per session down to 21 calls per session. Both species richness and bat activity were affected by temperature, with lower temperatures decreasing both, though bat activity was more significantly influenced. Wind speed was the most impactful variable, with species richness dropping from an average of 4.8 down to 2 and bat activity dropping from an average of 43 calls per session down to 16. We used ArcGIS Pro to calculate the distance between sites and the nearest source of water, and closer proximity to water generally resulted in higher bat activity and diversity. In conclusion, bat activity and presence is affected by numerous external variables.