Versatility of biosonar in the big brown bat, Eptesicus fuscus

Infrared cameras and ultrasonic microphones were used to record big brown bats (Eptesicus fuscus) flying in natural conditions at night while they hunted for insects. As expected, bats avoided obstacles while flying through vegetation and intercepted flying prey in the open. But bats also appeared to capture insects near and possibly on the ground and near or in vegetation, flew low over water to drink, and pursued each other in aerial “dogfights.” In less than a minute, the same bat often used echolocation for several different tasks, showing a wider repertoire of sonar-guided behavior than revealed by previous observations limited to seeing bats flying against the evening sky or being photographed in fixed fields-of-view.