Diversification across the Isthmus of Tehuantepec explains the phylogeographic arrangement of the widespread bright-rumped Attila (Attila spadiceus; Tyrannidae) and reveals the existence of two major lineages

Abstract

We describe the phylogeographic structure of Attila spadiceus, a neotropical bird with 12 recognized subspecies, through the analysis for partial Cytb amplicon region obtained from 11 subspecies. The topology recovered from the analysis indicated the existence of two principal molecular lineages and that the morphological variation underlying the designation of subspecies is not reflected in the mitochondrial gene tree. Based on these findings, we infer that the diversification of A. spadiceus began at the Pleistocene (~ 1.5 Mya), with the Isthmus of Tehuantepec region as the main factor driving the formation of two molecular lineages, one to the west and the other one to the east of this geographic barrier.