Movements of a male greater spotted eagle (Clanga clanga) during its 2^nd and 3^rd calendar years

The greater spotted eagle (Clanga clanga) is poorly known compared to other European eagles. We tracked an immature greater spotted eagle during 2018–2020 within the eastern European part of the species’ distribution, west of the Ural Mountains. Because so little is published about the annual movements of this species, especially from that region, tracking data from this single individual are valuable. 95% kernel density estimator (KDE) range sizes for the two complete winters in Yemen were 4,009 km² (2018), 1,889 km² (2019); 95% dynamic Brownian bridge movement models (dBBMM) encompassed 1,309 km² (2018) and 1,517 km² (2019). It returned to the same wintering area every year. During summer 2018, it settled into a small area (95% KDE = 126 km²; 95% dBBMM = 21 km²) near Birsk, eastern European Russia; in 2019 it wandered over a huge area (95% dBBMM = 66,304 km²) of western Kazakhstan and southern Russia, south west of Yekaterinburg. Spring migration 2018 was west of the Caspian Sea; during 2019 it was east of it. Mean speed of spring migration was 160±120 km/day during 2018, and 132±109 km/day during 2019. Autumn migration passed east of the Caspian in both years, and the mean speed of migration was 62 ± 78 km/day in 2018, and 84 ± 95 km/day in 2019. During both spring and autumn migrations, the eagle made stopovers, mostly lasting 1–2 days. The eastern Alborz Mountains in northeastern Iran appeared to be an important stopover locale, where autumn stopovers lasted 19 days (2018) and 27 days (2019). These and other data suggest that most greater spotted eagles that spend summers west of about 42°E, winter in southern Europe, Asian Turkey, the Levant and Africa, and those that summer to the east of that meridian winter in southern Asia, including Arabia.