It has been known for some time that fishing bats use echolocation to detect and classify acoustical cues from insects along and above water surfaces, and also to detect small water-dwelling prey breaking the water surface for a very short time.
But comparisons of echolocation behaviour of a single bat species performing prey captures under different conditions remains scarce. In a new study, Kirstin Übernickel and colleagues compared the echolocation and dip performance of the trawling bat Noctilio leporinus in Panamá when reacting to two different types of cues presented at a water surface using ultrasound recordings with synchronized high-speed video.
Results suggest that trawling bats possess the ability to modify their generally rather stereotyped echolocation behavior during approaches within very short reaction times.
Capture behavior usually began less than half a second before prey capture, but could also be realized in less than half the time if necessary. The bats were able to react to a cue very fast within approximately 50 ms. In the case of a disappearing cue, the bats probably used spatial memory to dip at the original location after its disappearance. Furthermore, in some failed capture attempts the bats continued to emit calls, likely to achieve fast updates of information for a subsequent capture attempt.