Determination of Migration Routes and Areas of Summer Vagrancy of Greater Spotted Eagles ( Clanga clanga , Accipitriformes, Accipitridae) in the First Year of Their Life Using GPS–GSM Telemetry

For young greater spotted eagles ( Clanga clanga ) tagged in the center of European Russia (four individuals) and in the Republic of Tatarstan (one individual), fall (2019) and spring (2020) migration routes and summer vagrancy routes, as well as stops during migration and vagrancy, were traced using GPS–GSM trackers. In contrast to birds from more western populations, e.g. Polish, Baltic, or Belarusian, some of which winter in Southern Europe, all the five spotted eagles studied were found to have migrated to wintering grounds in the Middle East. For the first time, the greater spotted eagle of the Volga population was recorded to have wintered near the southwestern coast of the Caspian Sea, and its migration route was found to be noticeably shorter than the routes of the other four individuals. The migration routes of two birds were revealed to have been circular: the fall route was along the eastern coast of the Black Sea, whereas the spring route, through the Bosporus and Dardanelles straits and then to the west of the Black Sea coast. Long stops during the fall migration were shown to be mainly determined by the presence of places with abundant potential prey along the migration track, which not all birds could find. Two individuals had long stops during the spring migration before crossing the Bosporus and Dardanelles straits, probably because of the absence of imprinting of migration route in young spotted eagles. The long stopover sites of the two birds during their summer vagrancies were located in the areas of extensive agriculture, this probably being due to readily available prey during harvesting.