History of the study of the winter bird fauna of the cities of Ukraine

Knowledge of wintering avifauna and the study of wintering aspects of birds make it possible to obtain information about the diversity and status of the populations of birds during one of the most unfavorable periods of their life. Significant changes in climatic conditions in winter period during the last decades in Europe are noticeable. They affect winter distribution and dynamics of a number of bird species. In particular, new species appear, what may be caused by changes in wintering places or migration routes, or birds that were previously migratory remain for the wintering. Therefore, systematic research of winter avifauna in the territory of urban agglomerations of different levels is a relevant and important task for today. In our opinion, the study of winter avifauna of urban agglomerations can be classified into several groups: year-round, global, partial and selective. The vast majority of winter avifauna studies were partial, conducted by scientists specializing in the study of individual species or groups of birds. Most often, ornithologists focused their attention on predators and birds of the wetland complex. Nowadays, according to the results of research conducted by ornithologists of Ukraine, we can distinguish three distinctive stages, which are not entirely clear, but reflect the development of research on winter avifauna and are indicative in the selection of research objects and territories. The first stage is the study of wintering birds of Ukraine of large water bodies or territories, such as areas with non-freezing ponds; the second – records and study of individual species or groups of birds, in particular wintering of shrikes, representatives of the Corvidae family, and the third – direct research of avifauna in urbocoenoses. The latter stage of research is the most recent. Now, ornithologists drew their attention to avifauna changes in urban agglomerations due to the increasing urbanization rates, which may cause a decrease in the species diversity and number of birds in cities in the nearest future, as a result of their displacement and the impossibility of staying in an anthropogenic environment.