| Large numbers of migratory tree bats are being killed at wind energy facilities across North America, and this rapidly growing source of renewable energy may pose a threat to bat populations. In 2012 and 2013 we conducted an ultrasound playback experiment, night vision surveys, and acoustic monitoring to determine if bats could be attracted to the smooth wind turbines surfaces because they perceive them to be water. Our playback experiment revealed little or no differences in the physical characteristics of echoes reflected from water and turbine surfaces. Our video and acoustic surveys indicated that bats behave at wind turbines as they do around water sources. Moreover, we observed bats attempting to drink from turbine towers at rates similar to water sources. Our data suggest that bats may be attracted to wind turbines because the surfaces produce an acoustic signature that is indistinguishable from water. |
