Diferenças e semelhanças nas culturas de canto em populações isoladas de bico-de-lacre (Estrilda astrild)

Abstract

The evolution of song cultures can reveal clues about the early stages of speciation. Variation in certain phenotypes indicates possible paths of divergence. The permanence of others suggests genetic limits to variation within the species. The learned songs of birds can diverge between isolated populations, generating dialects. Estrilda astrild (waxbill), native to Africa, was introduced in previous centuries to Brazil and southern Europe, forming geographically isolated groups. This study compares the songs of these populations to investigate the effects of isolation on vocal culture. To this end, 63 song recordings from each location were analyzed, manually segmented into motifs, and analyzed based on five acoustic parameters extracted via SAP. The data were subjected to univariate and multivariate statistical analyses, such as PERMANOVA, PCA, and hierarchical clustering. Conservation of the general song structure was observed between populations, with significant variations associated with geographic location. The clusters revealed partial separation between groups, with greater proximity between Brazil and Africa. These patterns indicate vocal differentiation linked to the long period of geographic isolation, although limited by intrinsic restrictions of the species.