Hunting in unfamiliar space:: echolocation in the Indian false vampire bat, Megaderma lyra, when gleaning prey

The literature suggests that in familiar laboratory settings, Indian false vampire bats (Megaderma lyra, family Megadermatidae) locate terrestrial prey with and without emitting echolocation calls in the dark and cease echolocating when simulated moonlit conditions presumably allow the use of vision. More recent laboratory-based research suggests that M. lyra uses echolocation throughout attacks but at emission rates much lower than those of other gleaning bats. We present data from wild-caught bats hunting for and capturing prey in unfamiliar conditions mimicking natural situations. By varying light level and substrate complexity we demonstrated that hunting M. lyra always emit echolocation calls and that emission patterns are the same regardless of light/substrate condition and similar to those of other wild-caught gleaning bats. Therefore, echoic information appears necessary for this species when hunting in unfamiliar situations, while, in the context of past research, echolocation may be supplanted by vision, spatial memory or both in familiar spaces.