Vocal variation in relation to genetic structure in an Atlantic forest woodcreeper ( Xiphorhynchus fuscus ): evolutionary and taxonomic implications

The analysis of intra-specific geographical variation is central to the study of the evolutionary and speciation processes, providing insights into the mechanisms leading to current diversity patterns. In the last decades, analyses of within-species variation moved its focus from phenotypic traits to the analysis of variation in genetic markers. Modern phylogeographic studies could be significantly improved by including detailed phenotypic variation analyses, allowing a better understanding of the biological processes driving similar or opposing patterns in phenotype and molecular markers differentiation. Here, we analyze vocal variation within the Lesser Woodcreeper (Xiphorhynchus fuscus), an Atlantic forest suboscine passerine, in relation to the genetic lineages previously described for this species. Our results show that two of the genetic clades within this species have their own vocal type, while the other two lineages share a common type. This finding supports the notion that the same events which modeled part of the genetic structure within X. fuscus also led to the accumulation of vocal differences. It also provides evidence to support the elevation of the subspecies atlanticus to a species-level taxon.