Acoustic difference in advertisement calls among two sympatric species: A confirmatory case to acoustic niche hypothesis and morphological constraint hypothesis.

In anurans, acoustic communication is the most important form of communication at the interspecific and intraspecific levels. Acoustic diagnostic features may be a potential alternative to morphometric and molecular diagnostics. Here, we assessed the variations in advertisement calls between two sympatric species, and , that share their breeding season and breeding sites. In addition, we investigated any potential relationships between call parameters and body size. We found that the advertisement calls of both species are simple calls. The two species exhibited significant differences in all call parameters. Both and showed a significant negative correlation with their body size on dominant frequency. These differences in call parameters may play an important role in interspecific recognition. Additionally, because intraspecific acoustic variation reflects body size, calls may be relevant for sexual selection. Our study supports the acoustic niche hypothesis and the morphological constraint hypothesis and calls are a valid tool for distinguishing between the two species of in the field.