Hybridization of Motacilla alba Linnaeus, 1758, and M. (a.) personata Gould, 1861, in the south of Siberia

The authors attempt to estimate the level of hybridization of Motacilla alba and M. (a.) personata in the area of their secondary contact in the south of Siberia. Processing of the materials in several museum collections (n = 424) and author’s own collections (n = 347) resulted in conclusion on the presence of introgression, in spite of limited hybridization. The data on pair composition and breeding success in the hybridization zone as well as data on habitat preferences are given. The possible reasons for the limited hybridization are discussed.