GENETIC BASE FOR SYMPATRY OF YELLOW WAGTAIL MOTACILLA FLAVA LINNAEUS, 1758 AND YELLOW-HEADED WAGTAIL MOTACILLA CITREOLA PALLAS, 1776 (MOTACILLIDAE, PASSERIFORMES) IN THE MIDDLE VOLGA REGION
We investigated the genetic basis between sympatric breeding population yellow wagtail Motacilla flava and yellow-headed wagtail Motacilla citreola in the Middle Volga region. We lead the phylogeographic analysis of the nucleotide sequences in the mitochondrial gene of oxidase I cytochromes in yellow wagtail Motacilla flava and yellow headed wagtail M. citreola populations of Middle Volga. As part of the traditionally recognized species M. flava and M. citreola revealed the existence of separate lines, common in the European part of Russia and neighboring countries and associated with the presence of Middle Volga populations of subspecies of M. f. flava, M. f. thunbergi and M. c. citreola, M. c. werae respectively. The forms of M. c. citreola and M. c. werae due to significant genetic distances deserve assigning them the status of the species. These results suggest that, despite the broad sympatry in nesting places, there is a selective mating between males and females of each species studied, which prevents from the free crossing and supports the insulating mechanisms in populations