Abstract

Acoustic signals are the main communication vehicle for most anuran species, and males typically use advertisement calls to attract females and to interact with other males in a chorus. The role of the environment in the evolution of the advertisement call is still largely unknown, and the recognition of different selective pressures may improve our understanding of anuran communication system. The aim of this study was to investigate the effect of micro-habitat at calling sites on advertisement call structure and propagation in a population of the treefrog Hypsiboas crepitans. Males of this species typically call from elevated sites in vegetation or from sites where their body is partially submerged in water. Our analysis of call parameters of males calling from these sites showed that both dominant frequency and pulse rate were significantly lower when males called partially submerged in water compared to males calling from elevated sites in vegetation. Both pulse rate and dominant frequency have been shown to be important in species recognition among anurans, and they play a role in sexual selection and sound propagation. Our analysis of the effect of calling site (elevated or partially submerged) on signal propagation showed that the efficiency of transmission did not differ between sites.