Taxonomia do complexo Hylophilus poicilotis (Aves: Vireonidae)

Abstract

The Hylophilus poicilotis complex has been the object of many taxonomic revisions, all of them having in common the absence of adequate reference material, which resulted in a large number of questions, most of them focusing on H. amaurocephalus, which was treated as a full species on occasions or as a subspecies of H. poicilotis on others, mainly because of the hypothetical presence of an intergradation zone between these two taxa. The present work surveyed the taxonomy of this group and the alleged occurrence of hybridization between these two taxa, as well as testing the presence of regional variants within this complex. For these purposes, I examined the bird series available in 11 institutions and also recorded comparative aspects of vocalisations and ostheological morphometric characters of some specimens obtained in field work. The resultant data indicate that H. poicilotis and H. amaurocephalus must be considered as independent species, and the presence of some character gradation is not related with the occurrence of hybridization in this group. This work also exposes the fragility of the diagnosis based on vocal characters, as there are a rather large amount of variation recorded within this complex.