Evolution of acoustic signals in Neotropical leaf frogs

Abstract

Acoustic signals have been presumed to show high evolutionary divergence levels, with similar constraints and selective pressures often leading to convergence among distant lineages. However, few studies have applied a rigorous phylogenetic approach to investigate historical changes in anuran vocalizations. Here, we investigated which factors may be shaping acoustic signals in Neotropical leaf frogs by testing correlations among acoustic variables, species body size and habitat structure. The study was conducted in a comprehensive sampling, composed by the clade formed by treefrogs of the genera Callimedusa, Phyllomedusa and Pithecopus (Phyllomedusidae). We found a significant inverse correlation between body size and the dominant frequency of calls, but not between body size and call duration. Unexpectedly, no acoustic variable was significantly correlated with habitat type. However, habitat type showed a high phylogenetic signal. We suggest that the influence of different spatial scales should be appropriately addressed in broader tests with anurans and that more studies focusing on the evolution of calls in particular clades should be conducted instead of seeking general rules across clades.