Vocal geographic variation in mesoamerican Common Bush Tanagers (Chlorospingus ophthalmicus)

We studied patterns of geographic variation in the fine structural characteristics of the songs of five recognized subspecies of Common Bush Tanagers (Chlorospingus ophthalmicus) in Mesoamerica to examine whether songs vary with geography. Multivariate analyses (PCA and DFA), based on 11 fine structural characteristics of the songs provided similar results indicating that both albifrons and regionalis had unique songs significantly different from the rest of the subspecies. Conversely, ophthalmicus, dwighti, and postocularis had similar song characteristics, regardless of restricted gene flow and substantial morphological variation reported in previous studies. Our findings suggest there is a possible relationship between the length of isolation and variation in songs of albifrons and regionalis, whereas the lack of divergence in songs of ophthalmicus, dwighti, and postocularis suggests some of these forms have not diverged vocally, and vocal traits may be evolutionary conserved.