Molecular systematics of the Amazonian endemic genusHylexetastes(Aves: Dendrocolaptidae): taxonomic and conservation implications

Hylexetasteswoodcreepers are endemic to theterra firmeforests of the Amazon basin. Currently, most taxonomic sources recognize two species ofHylexetastes(H. perrotiiandH. stresemanni), each divided into three subspecies. Some authors maintain that theH. perrotiisubspecies should be elevated to full species status. In particular,Hylexetastes perrotii brigidaiis endemic to the eastern Amazon, the second Amazonian area of endemism (Xingu) most affected by deforestation and habitat degradation. Consequently, the taxonomic status ofH. p. brigidaiis of particular concern for conservation. Thus far, only morphological characters have been evaluated for the taxonomic delimitation of species and subspecies ofHylexetastes. We present a molecular phylogenetic analysis of all subspecies to help delimitHylexetastesinterspecific limits. Fragments of two mitochondrial (CytbandND2) and three nuclear genes (FGB5, G3PDHandMUSK) from 57Hylexetastesspecimens were sequenced. An ecological niche model was estimated to describe more accurately the potential distributions of taxa and to evaluate their vulnerability to ongoing deforestation. Phylogenetic analyses support the paraphyly of the polytypicH. perrotiias currently delimited and the elevation ofHylexetastes perrotii uniformisto full species rank, as well as the presence of three evolutionary significant units (ESUs) within this newly delimited species, including one grouping allH. p. brigidaispecimens. Alternatively, under lineage-based species concepts, our results support at least five evolutionary species inHylexetastes:H. stresemanni,H. undulatus,H. perrotii,H. uniformisandH. brigidai. Each of these taxa andESUs are distributed in different interfluvial areas of the Amazon basin, which have different degrees of disturbance. Because they occupy the most heavily impacted region among allHylexetastesESUs, regular assessments of the conservation statuses ofH. p. brigidaiand bothH. uniformisESUs are paramount.