Foraging and public information use in common pipistrelle bats (Pipistrellus pipistrellus): a field experiment

Decision making by animals is likely to be influenced strongly by the behaviour of conspecifics. In this study we tested whether public information affected the foraging behaviour of common pipistrelles (Pipistrellus pipistrellus) by manipulating public information about the quality of foraging patches. Capture attempts during foraging are revealed by terminal buzzes, which are a potential source of public information about prey abundance for other foraging bats. We tested whether the estimation of food patch quality was affected by the number of terminal buzzes emitted by conspecifics. We conducted an experiment at 12 different locations in an urban habitat in the Netherlands. At each location we played back recordings of echolocation sounds of hunting bats with different terminal buzz rates and scored the bat activity. No significant differences between treatments were found. Our results do not support the hypothesis that bat activity increases in response to an increase in simulated terminal buzzes, suggesting that public information does not influence the choice of foraging patches in P. pipistrellus. We propose that P. pipistrellus does not use this kind of information because of either the high reliability of personal information or of the low collection costs associated with personal information.