Hybridization as a result of spatial and reproductive interactions between species within the group of ‘yellow’ wagtails (Aves, Motacillidae) in areas of sympatry

The area of overlapping ranges, contact and relationships two closely related species—the western yellow wagtail Motacilla flava Linnaeus, 1758 the yellow-headed lutea (Gmelin, 1774)—in Volga region are subject present study. At present, under conditions wide sympatry, there is spatial reproductive interaction between these wagtails. Crossbreeding species ‘yellow’ wagtails gives a light-headed form hybrids, which marker hybrid zone in region. As result study M. their areas following was revealed. concept system traits (M. f. beema × lutea), marking hybridization model lutea, postulated. population characteristics this have been determined possibility use evolutionary studies group has shown. populations, lutea) formed, integrates characters original its own, peculiar traits, can mark boundaries (left-bank) eastern (right-bank) groups populations distribution. On basis this, differences formed divergence occurs, may reflect processes sympatric speciation. revealed tendencies variability space ranges clinal character indicate directions microevolution species. identified zones within central position. results spatio-temporal flava, later become an independent In unlimited