Spanish Short-toed Eagles summering in Northwest Africa

After leaving their Sahelian wintering grounds, immature Spanish Short-toed Snake Eagles spend the summer in northern Africa instead of going back to their natal areas.

The importance of the breeding and wintering areas of a bird population for understanding demography and for determining conservation strategies is well recognised. However, the other areas where birds spend also a significant amount of time during their annual cycle – such as stopover or staging areas, and summering areas – are not well studied.

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. But until now, we don’t known very much about their whereabouts outside of these two periods.

Mellone and his team tagged nine Short-toed Snake Eagle nestlings 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, the birds settled mostly in northeastern Morocco, but also in northern Algeria, thus not returning to Europe either in their second or third summer (see map). 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.

Reference:

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.

Staging areas of immature Short-toed Snake Eagles during summer. Each number corresponds to a different staging area. ‘C’ (Cadiz) and ‘A’ (Alicante) are the nesting areas where the birds were tagged in southern Spain.
Staging areas of immature Short-toed Snake Eagles during summer. Each number corresponds to a different staging area. ‘C’ (Cadiz) and ‘A’ (Alicante) are the nesting areas where the birds were tagged in southern Spain.
Short-toed Snake Eagle (Circaetus gallicus) by Michele Panuccio
Short-toed Snake Eagle (Circaetus gallicus) by Michele Panuccio

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