Abstract
Two Acoustic and Thermographic Offshore Monitoring (ATOM) systems were deployed on wind turbines 42 km offshore to monitor bat activity throughout the year and around-the-clock, using thermal imagery, ambient-light video, and acoustic detectors. We documented a strong seasonal pattern, with 89% of bat detections occurring during late summer and early autumn. We recorded 31-38% of bat detections during daytime. Bats were present while turbine blades were spinning (64% of video detections), and although we occasionally documented altered flight paths, we never recorded a collision. Our results highlight the need for increased monitoring, using innovative and complementary methods, to understand bat presence and behavior in the offshore environment.