Hunting strategies and foraging performance of the short‐toed eagle in the Dadia‐Lefkimi‐Soufli National Park, north‐east Greece

Abstract

The foraging performance and the hunting strategies of foraging short-toed eagles Circaetus gallicus were studied in Dadia-Lefkimi-Soufli National Park during 1996–1998. A general linear model analysis showed that the eagle's hunting mode was related to wind velocity. At low wind speeds, the eagles more frequently soared and/or hovered, whereas on windy days, they hung more frequently than soared or hovered. Individuals appear to compensate for the high-cost foraging method (hovering) with a high capture rate or a low capture rate with low-cost foraging methods (soaring and hanging). In addition, their foraging activities exhibited two patterns. In the early (April) and late (September) breeding season, eagles foraged mainly during midday, while from May to August eagles foraged largely during the morning and a little during the afternoon, reflecting to some extent the diurnal activity of prey (reptiles) throughout the breeding season. Short-toed eagles tended to forage for longer as the breeding season progressed, peaking during August due to additional food requirements before autumn migration. Following a mixed foraging strategy throughout the breeding season, short-toed eagles increased their hunting efficiency, which may benefit increased breeding success and energy reserves for migration.