Long-Term Population Dynamics of Large Raptors in the Important Bird Area “Kamsko-Bakaldinskiye Marshes” (Nizhny Novgorod Region)

Identification of breeding territories and long-term population monitoring has been carried out in the Important Bird Areas (IBA) with a global importance “Kamsko-Bakaldinskiye marshes” since 1980. Five large bird species were studied here: Osprey (Pandion haliaetus), Short-Toed Eagle (Circaetus gallicus), Greater Spotted Eagle (Aquila [Clanga] clanga), Golden Eagle (Aquila chrysaetos), White-Tailed Eagle (Haliaeetus albicilla). In this report we will summarize the results. IBA covers the northern (Zavolzhsky) part of the Lyskovsky and Vorotynsky districts of the Nizhny Novgorod region, as well as the adjacent areas of Borsky, Semenovsky, and Voskresensky districts. Its total area is 3156.0 km2. The largest massif of upland, transitional, and lowland bogs in the Volga River basin is preserved here in its natural state. A significant part of IBA area (2265 km2) is listed as Ramsar wetland of international importance. Kamsko-Bakaldinskiye marshes has undergone significant transformation over the past 50 years. Until the 1980s, intensive logging was carried out here with an excess areas were organized by 1994, covering 54% of IBA area and leading to a decrease in logging volumes. In the 1980s drainage and peat extraction amounted to 1% of an area. Disastrous fires of 1972 and 2010 spread through about 50% of an area. The number of rare raptor species was positively influenced by the implementation of a unique project to install 62 nesting platforms in 1998–2014. Multidirectional vectors – the destruction of habitats and their conservation, combined with compensatory biotechnical measures, superimposed on the general population trends of large raptors in the center of the European part of Russia. As a result, the population dynamics of different species in Kamsko-Bakaldinskiye marshes differs significantly. The population dynamic for four out of five studied species shows a clear positive trend. Thus, the number of Osprey and White-Tailed Eagle has increased by three and six times, respectively. A project that included nesting platform installation had a significant impact on Osprey population. White-Tailed Eagle depended on it to a lesser extent, however, throughout an entire observation period, there was a general positive trend in the abundance of the species in the European part of Russia. The negative impact of catastrophic fires in 2010 on Osprey and White-Tailed Eagle was insignificant. Abundance of Short-Toed Eagle and Greater Spotted Eagle in 2000–201