Ocorrência e evolução da vocalização em alta frequência em beija-flores (Aves: Trochilidae)

Abstract

The growing number of studies in bioacoustics has brought to light previously unknown behaviors for several animal groups, such as the ability of hummingbirds (Aves: Trochilidae) to vocalize at high frequencies (i.e., peak frequency >10kHz). Due to this recent finding, studies are scarce, and it is possible that other species of this family have this same ability, whose evolutionary origin and maintenance in the group are still poorly known. Thus, this study aimed to answer: 1) How many and which hummingbird species are able to produce high-frequency vocalizations? 2) Are vocalization frequencies, habitat and species mass factors that present a phylogenetic signal in Trochilidae? 3) What was the origin and mode of evolution of highfrequency vocalization and the type of habitat associated with high-frequency vocalizations in Trochilidae (acoustic adaptation hypothesis)? 4) Is there a relationship between species morphology and acoustic parameters? We determined the vocalization frequencies of 82% of the species in the family. Then, w subsequently analyzed the phylogenetic signal and performed ancestral state reconstruction for 81% of Trochilidae species, based on the most recent and broad phylogenetic hypothesis for the group. Our study expanded the number of hummingbird species able to vocalize at high frequencies from five to 29 and found no evolutionary factors that relate habitat and mass to vocalization frequency. The results suggest that the evolution of vocalization at high frequencies in hummingbirds may be related to behavioral rather than environmental factors, and it is important that ongoing and future studies investigate (i) the influence of behavioral context on the vocalization of Trochilidae individuals and species and (ii) the neurological ability to process acoustic signals at high frequency. The taxonomic scale of our study in Trochilidae is pioneer and was possible through citizen science data. Our findings may be revisited with the inclusion of molecular sequences in databases of those representatives of Trochilidae that have not yet been molecularly characterized expanding the inference of an even more robust acoustic macroevolutionary scenario for Trochilidae.