A field observation method to characterize site soundscape and improve detection probability estimation for eastern bat species in North America

Acoustic monitoring of bat activity has become increasingly prevalent in recent years. A major challenge is imperfect detection caused by bat behavior and the physical soundscape. Although environmental factors such as weather are commonly considered to account for imperfect detection, there is a lack of an easy-to-use, widely applicable protocol for characterizing soundscapes. We introduce a field-based observation method requiring minimal training to characterize the soundscape. Results from two case studies demonstrate that, in both temperate forest and grassland ecosystems, our soundscape measures better explained imperfect detection than weather conditions for eastern bat species in North America. We emphasize that soundscape characteristics should be considered when selecting acoustic monitoring sites and incorporated into quantitative analyses of ecological processes.