The influence of the Sayano-Shushenskaya Dam reservoir on the nesting and abundance of the osprey (Pandion haliaetus L., 1758)

The paper presents the materials of the study of the osprey grouping on the territory of the Sayano-Shushensky Nature Reserve. Before the formation of the reservoir, 3–4 osprey nests were recorded on the banks of the Yenisei. The flooding of the valley was accompanied by the formation of extensive flat areas suitable for nesting. The volume of fish resources that form the basis of the osprey’s food supply has increased and their availability is one of the main criteria of the ecosystem, on which the number of this rare bird depends. Continuous monitoring of the osprey grouping on the shores of the Sayano-Shushenskaya Dam reservoir within the Sayano-Shushensky Nature Reserve began in 2012. The work included a survey of suitable habitats in order to identify nesting sites, certification of nests, accounting of adult birds, as well as monitoring the reproduction of ospreys. Based on the results of the research, it was possible to create a model of optimal natural conditions for nesting ospreys in the mountainous regions of Siberia. The creation of a large artificial reservoir has had a positive impact on the number of protected groups of ospreys. A special regime of strict protection peculiar to biosphere reserves plays a positive role, which excludes visits to nest bays, significantly reducing the anxiety factor. Together, this allows the birds to expand the nesting areas and breed offspring.