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

The African saw-wings (genus Psalidoprocne) 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 Psalidoprocne. 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.