Divergence in mating signals predicts behavioral responses among three closely related species of wrens in the genus Campylorhynchus

In contrast, C. capistratus displayed consistently weaker responses across all treatments, which may indicate reduced reliance on vocalizations or alternative mechanisms for recognition. These findings align with genetic, morphological, and vocal divergence patterns previously documented for these taxa, supporting the hypothesis that vocalizations play a pivotal role in delineating species boundaries. The data suggest that song divergence in allopatric populations is a key factor in maintaining reproductive isolation.

This underscores the broader evolutionary significance of acoustic signals in avian speciation and highlights the utility of playback experiments as a tool for assessing species limits and understanding the mechanisms driving speciation. Researchers can use this approach to further investigate the interaction between vocal divergence, ecological context, and evolutionary processes in other avian systems.