Geographical variation of social calls and vocal discrimination in male Himalayan leaf-nosed bats

Abstract

Like birds and many other animals, bats produce diverse acoustic calls for social communication. Geographical variation in social acoustic signals and perceptual discrimination abilities are well studied in birds but largely unexplored in bats. In this study, we recorded male territorial calls of the great Himalayan leaf-nosed bat, Hipposideros armiger, from nine colonies at a large geographical scale and investigated the patterns and causes of geographical variation in acoustic signals. We also performed habituation−dishabituation playbacks to investigate whether males could discriminate between territorial calls of their own versus a foreign colony. Overall, our results showed significant geographical variation in calls across colonies. Neither climatic differences, morphological differences, geographical distances nor genetic distances between colonies explained the observed acoustic variation between colonies. A playback experiment indicated that males from eastern China were able to discriminate between calls of males from their own colony and those of males from a colony in southwestern China. This study provides the first experimental evidence that bats can discriminate geographical variation in social calls.