Some aspects of nesting biology and ecology of Motacilla tschutschensis plexa and Motacilla flava beema in Western Siberia

The taxonomy of the Yellow Wagtail Motacilla flava sensu lato is very complicated and not fully resolved as yet. Here, we report on the nesting biology and ecology of two subspecies - Motacilla tschutschensis plexa and Motacilla flava beema. The birds were studied in southwest and central parts of Western Siberia. The accounting of animal unit on trial area and routes was made, the nests and eggs were described and the plumage characteristics of adult Wagtails were noted. It appeared that both subspecies chose different microhabitats where they constructed their nests and they differed with respect to the main oological indicators. The nesting density of M. t. plexa increased in technogenic transformed sites of complex raised bogs, compared to relatively less violated habitats. Some adult individuals of M. t. plexa were characterized by a gray coloring of the hat and the mask expressed by the eyebrow.