The importance of data on the non-breeding fraction of a bird population for understanding demography and for determining conservation strategies is well recognized, especially in long-lived species such as raptors. Short-toed Snake Eagle (Circaetus gallicus) is a migratory raptor that breeds in Europe and northern Africa, and spends the winter in sub-Saharan Africa.
Nine Short-toed Snake Eagle nestlings were tagged with satellite transmitters a few days before fledging. Six individuals were tagged with Microwave Telemetry 45-g solar/GPS transmitters in the province of Alicante (southeastern Spain) in 2008 and 2009. The other three birds were tagged with North Star 30-g solar/GPS transmitters in the province of Cadiz (southern Spain) in 2009.
Immature Short-toed Snake Eagles left their wintering Sahelian grounds by mid-April, which is rather late in the season compared to adults. After crossing the Sahara Desert, birds settled mostly in northeastern Morocco, but also in northern Algeria, thus not returning to Europe either in their second or third summer. This study shows that conservation strategies for migratory long-lived species should not be solely focused on breeding and wintering grounds, but should consider also those events occurring in non-breeding summering areas, which could have important consequences at the population level.
Mellone, U., Yáñez, B., Limiñana, R., Muñoz, A.R., Pavón, D., González, J.M., Urios, V. & Ferrer, M. 2011. Summer staging areas of non-breeding Short-toed Snake Eagles Circaetus gallicus. Bird Study 58: 516-521. doi: 10.1080/00063657.2011.598914