Evaluating the trade-off between investing in coloration and vocalizations in finches (Fringillidae), a passerine group of complex signals

CASALE, AGUSTÍN I.; TUBARO, PABLO L.; LIJTMAER, DARÍO A.

Congreso; VII North American Ornithological Conference (virtual); 2020

American Ornithological Society y otras 6 sociedades de ornitología de América

The interaction between multiple secondary sexual characters simultaneously expressed by an organism is one of the less understood aspects of sexual selection. In fact, different interpretations of the role of multiple simultaneous signals predict that the correlation of their complexity across species should be positive, negative or absent, three possibilities that were supported by the study of different avian groups. In this context, we analyzed the interaction between color complexity and song elaboration in the passerine family Fringillidae. We used a two-scale approach and studied this association both at the family level, by comparing the songs between the species with the most and the least complex color in each genus, and within the genus Crithagra, which shows gradual variation in color across its species. At both scales, we analyzed the association between color complexity, established by analyzing the number of plumage color patches in each species and their conspicuity, and three aspects of vocal elaboration: energy investment (song length and rate of syllable production), song complexity (repertoire index) and vocal performance (vocal deviation). A total of 1,342 songs from 449 individuals of 81 species were analyzed. We found an absence of association between the complexity of coloration and the three evaluated aspects of song elaboration at both scales. Our analysis also indicates that finches can have a remarkable vocal performance compared to other groups of birds. Taken together, our results suggest that visual and acoustic signals in this family could have different roles in the context of sexual selection.