Measuring bat activity levels through use of acoustic detection techniques.

Abstract

White-Nose Syndrome (WNS), a fungal infection caused by Pseudogymnoascus destructans, has been decimating North American bat populations since its introduction in 2006. This disease and the bats it infects are not well understood, which calls for the development of techniques to monitor bats and eventually develop ways of combating WNS. We used a system of acoustic detection to monitor nightly bat activity levels in order to establish a baseline activity level before WNS infects local populations. We also attempted to gather data on variation in bat activity due to time, date, and weather conditions to better understand and monitor bat populations. We hypothesized that bat activity would increase with rising temperatures and decrease with inclement weather. Total bat activity increased significantly with temperature (least squares regression slope=2.08, F=4.851, p=0.034) and decreased significantly with the time after sunset that the survey began (slope=-0.02, F=16.674, p<0.001). We recommend an annual, week-long period of bat monitoring for future studies to obtain similar baseline levels of bat activity.