Greater Horseshoe Bats Recognize the Sex and Individual Identity of Conspecifics from Their Echolocation Calls

Simple Summary Recognition is crucial for many aspects of an animal's life and directly affects its fitness. The aim of this study was to investigate whether greater horseshoe bats can recognize a conspecific's sex and individual identity from its echolocation call alone. Through playback experiments, we demonstrated that greater horseshoe bats can recognize the sex and individual identity of conspecifics from their echolocation calls, which indicates that the echolocation calls of greater horseshoe bats may have potential communication functions. The results of this study improve our understanding of the communication function of the echolocation calls of bats. The echolocation calls of bats are mainly used for navigation and foraging; however, they may also contain social information about the emitter and facilitate social interactions. In this study, we recorded the echolocation calls of greater horseshoe bats (Rhinolophus ferrumequinum) and analyzed the acoustic parameter differences between the sexes and among individuals. Then, we performed habituation-discrimination playback experiments to test whether greater horseshoe bats could recognize the sex and individual identity of conspecifics from their echolocation calls. The results showed that there were significant differences in the echolocation call parameters between sexes and among individuals. When we switched playback files from a habituated stimuli to a dishabituated stimuli, the tested bats exhibited obvious behavioral responses, including nodding, ear or body movement, and echolocation emission. The results showed that R. ferrumequinum can recognize the sex and individual identity of conspecifics from their echolocation calls alone, which indicates that the echolocation calls of R. ferrumequinum may have potential communication functions. The results of this study improve our understanding of the communication function of the echolocation calls of bats.