Geographically widespread mitochondrial lineages of the African saw-wings inconsistent with species boundaries

The African saw-wings (genus <i>Psalidoprocne</i>) are a group of swallows endemic to sub-Saharan Africa. Although currently described as five species with several subspecies, the taxonomy of the saw-wings is unclear. We sequenced two mitochondrial genes (ND2 and cytb; 1 717 sites) from 20 individuals in order to investigate phylogenetic relationships across the range of <i>Psalidoprocne</i>. We obtained similar results from maximum likelihood (RAxML) and Bayesian (BEAST) phylogenetic analyses, which reveal multiple well-supported mitochondrial clades in the genus. The geographic overlap of distinct lineages suggests reproductive isolation, although these clades do not correspond entirely to current species designations.