NUMBER OF BREEDING IN THE TERRITORY OF THE ROSTOVSKY RESERVE OF PELICANS (PELECANIDAE) AND THE CAUSES OF FLUCTUATIONS IN NUMBERS
There were estimated a population size and nesting sitesof Dalmatian pelican (Pelicanus crispus) and Great White Pelican (Pelicanus onocrotalus) on Rostov Nature Reserve territory since 1995 to 2020. Establishing the reserve enabled the conservation of the bird species on the territory. The Dalmatian pelican is a near threatened and regularly nesting species and the Great White pelican is the least concern and rarely nesting species what can be explainedby their biological features. In the research there was made a nesting places specification. The research shows that drying out waters, increasing of water salinity, fish resources reduction could be defined as a deterrent factors for population size of the pelican species.