Assessing bat community, activity, and roost use at Meanook National Wildlife Area through stationary acoustic monitoring and roost exit counts

The Meanook National Wildlife Area (NWA) bat monitoring project used a combination of stationary acoustic detectors and roost exit counts to evaluate bat species diversity, seasonal activity patterns, variance in habitat usage between species, and maternity roost dynamics in an artificial bat box. Ultrasonic bat detectors were deployed at three bat-attractive locations within the wildlife area during June-July of 2023-2025 to characterize species diversity, community composition, seasonal activity, and variation in habitat use, along with changes in these factors between years. Each detector was deployed for a period of at least seven days in June - July when the weather was forecasted to be appropriate (no rain, low winds). Sites were selected to minimize acoustic clutter, avoid roost-adjacent areas with high bat concentrations, and reduce sound distortion from reflective surfaces. Detectors were mounted on trees with microphones suspended above ground angled away from the tree and programmed to record from thirty minutes before sunrise to thirty minutes after sunrise, triggered by ultrasonic noise. Acoustic files from stationary monitoring were analyzed by an expert using the Wood Buffalo regional classifier in SonoBat 30.0, with manual review in SonoVet to assign each file to a species or species group. Over the three years, more than 96% of acoustic recordings were successfully classified. Since 2023, six species have been identified within Meanook NWA: little brown bats, hoary bats, silver-haired bats, big brown bats, northern myotis, and eastern red bats. Bat activity was consistently dominated by little brown bats, followed by hoary bats and silver-haired bats. In addition to acoustic monitoring, roost exit counts were conducted twice annually between early June and early July to estimate the mature adult population size of a little brown bat maternity colony occupying a bat box within the Meanook NWA area. Observers independently counted bats exiting and re-entering the roost at dusk through the use of handheld counters. Average counts ranged from 90-176 bats during the first surveys and 179-195 bats during the second surveys each year, with strong agreement between observers.