Acoustic and morphological variation on two populations of Dryophytes arenicolor in central México

Abstract

ABSTRACT Contrasting conditions of different habitats lead to geographic variation among populations of the same species. In widespread species, trait divergence represents a response to spatial variation in local habitat conditions and biotic interactions. Morphology and call characteristics are crucial for anuran fitness because of their direct impacts on survival and reproduction. Our aim was to analyse and compare morphological and call characteristics of two populations of Dryophytes arenicolor in central Mexico where waterbody types and presence of other species (D. eximius) differed. We measured morphological characteristics, estimated the sex ratio, and characterised the advertisement calls for each population. We found that the sex ratio differed among populations: in one population, the sex ratio was male-biased. No morphological variation was detected between populations; however, females had longer limbs and higher mass. We found differences in call characteristics among populations and even among individuals of the same population. There was an effect of calling context (solitary or chorus) on call characteristics, we found that calls from conspecifics led to an increase in values of spectral characteristics and reduction of temporal ones, whereas calls from D. eximius resulted in a decrease in values of spectral characteristics and increase in temporal ones.