Molecular phylogeny of Ortalis poliocephala, a Mexican endemic bird species

The West Mexican Chachalaca (Ortalis poliocephala) is a bird species distributed in different habitats on the Pacific slope of Mexico. Despite being endemic and having declining populations, the species is classified as Least Concern in Mexico and by the IUCN. Analysis of genetic data brings us closer to understanding the phylogenetic relationships and genealogical histories of different taxa. In this study, we analyzed the genetic diversity indices of six O. poliocephalaindividuals from the Balsas Basin region (state of Michoacan) using the molecular markers COI, ND2 and Cytb. We also estimated the genetic distance between the Ortalis species, as well as the phylogenetic relationships and divergence times of the genera Ortalis, Crax, Mitu, Nothocrax, Oreophasis and Pauxi. The genetic diversity indices of O. poliocephala suggest accelerated population growth from a small effective population size. Analysis of paired genetic distances within the genus Ortalis showed that the species O. ruficauda and O. garrula have the smallest genetic distance, and the species O. vetula and O. poliocephala have the largest genetic distance. The phylogenetic analysis of the species belonging to the genera Ortalis, Crax, Mitu, Nothocrax, Oreophasis and Pauxi, allowed us to corroborate the monophyly of Ortalis and the identification of two genetic lineages among the O. poliocephala individuals analyzed, which coexist in the Balsas Basin region in Michoacan. Based on divergence times estimates, we propose that O. poliocephala originated approximately 1.94 million years ago in the Mexican transition zone, and that the diversification of the two identified genetic lineages occurred 270,000 years ago.