Function of pipistrelle social calls: field data and a playback experiment

The function of social calls produced by feeding bats of two phonic types of Pipistrellus pipistrellus was investigated by analyzing data gathered from a foraging site and by playback experiments. Results indicated that social calls are used to repel, rather than to invite, other bats of the same phonic types when food source is scarce. Moreover, results suggested that there is resource partitioning between phonic types because there is no evidence of communication between them.