Determination of contact zones between two species of the genus Leistes (Vigors, 1825) (Passeriformes: Icteridae) in South America

Abstract

Leistes militaris (Linnaeus, 1758) and L. superciliaris (Bonaparte, 1850) have been undergoing expansion of their geographic distributions due to the transformation of natural landscapes into pastures or monocultures in Latin America, assuming the possibility of establishing contact zones between the two species. Thus, from a review of the geographic distribution of those species, supported by photographic records from the WikiAves portal for Brazil and by literature records for Peru and Bolivia, the objective of this study was to verify the existence of contact zones between the two species. The compiled records showed an extension of the occurrence of L. militaris in 27% in the total area of the geographic distribution of the species, while for L. superciliaris the extension of occurrence had an increase of 12.7% of its area. The overlap between the extensions of the geographic distributions of the species indicated the existence of three distinct contact zones presents in the limits of the Amazon-Cerrado ecotone in Brazil and in Bolivia, and in the Caatinga biome, in northeastern Brazil. Hybridization events were conjectured due to syntopy between the two species, previously disjunct in their geographic distributions.