Genomes of the extinct Bachman’s Warbler show high divergence and no evidence of admixture with other extant Vermivora Warblers

Bachman’s Warbler (Vermivora bachmanii) – last sighted in 1988 – is one of the only North American passerines to have gone extinct. Given extensive ongoing hybridization of its two extant congeners – the Blue-Winged Warbler (V. cyanoptera) and Golden-Winged Warbler (V. chrysoptera) – and shared patterns of plumage variation between Bachman’s Warbler and hybrids between those extant species, it has been suggested that Bachman’s Warbler might have also had a component of hybrid ancestry. Here, we use historic DNA (hDNA) and whole genomes of Bachman’s Warblers collected at the turn of the 20th century to address this. We combine these data with the two extant Vermivora species to examine patterns of population differentiation, inbreeding, and gene flow. In contrast to the admixture hypothesis, the genomic evidence is consistent with V. bachmanii having been a highly divergent, reproductively isolated species, with no evidence of introgression. We show that these three species have similar ..., The dataset includes detailed sample information for the genomic samples included in the study. The information comes from collection databases (for museum samples) and field data for the wild caught birds in the study., The files include a README (accessible via Microsoft Word) and a .CSV file which can be opened in any spreadsheet software.