AUTHORS: Yoshihiro Yajima, Brown Univeristy; Kim A. Medley, Washington University in St. Louis; Erin O'Connell, Washington University in St. Louis; Vona Kuczynska, U.S. Fish and Wildlife Service; Shelly Colatskie, Missouri Department of Conservation; Elizabeth Biro, Washington University in St. Louis; Solny Adalsteinsson, Washington University in St. Louis
ABSTRACT: Human-driven land-use change is the second most important cause of biodiversity loss worldwide. Species like bats that rely heavily on forest resources to forage and reproduce are impacted by increasingly fragmented habitats. Here, we investigated habitat suitability for federally-endangered Indiana bats (Myotis sodalis) across a 2,000 acre university field station, Tyson Research Center (TRC), in St. Louis County, Missouri. TRC has long been impacted by human development, including encroachment of urban land-use. To understand the current distribution of M. sodalis, we recorded bat echolocation calls using 65 AudioMoths placed in a grid across TRC during June 2023. We processed audio files using Kaleidoscope Pro to classify calls to species and manually vetted all calls classified as Myotis spp. We then used MaxEnt, a presence-only niche-based modeling algorithm, to identify important environmental features for M. sodalis activity and create a habitat suitability map for TRC. By manually vetting over 1000 audio files, we identified 12 M. sodalis presence locations and created a model with 10 environmental variables. We found that level ground and snag stands were the most influential predictors of M. sodalis habitat suitability, which was consistent with mist net and telemetry studies. This result suggests that the species typically use flat openings near dead standing trees as day roosts, potentially to reduce energy expenditure on flight while having adequate access to insect prey. Our results elucidate how M. sodalis use forests surrounded by human development and will help guide future management action to conserve threatened and endangered bats.
