Thursday 8 March 2012


Booted Eagle (Hieraaetus pennatus). Brava, adult female fitted with a satellite transmitter
and released at Los Canchales Reservoir, Badajoz. By Ángel Sánchez.

An ambitious SEO/BirdLife bird migration project kicked off in 2011, its remit including satellite tracking. One of the star species is Booted Eagle (Hieraaetus pennatus). The movements of six tracked birds can now be followed live on internet (click here). Two of these birds, forming part of a project being run by Junta de Extremadura, were the first to begin their autumn migration and reach their African destinations in 2011. The return spring migration is now underway, so it's the perfect time to report the movements to date of both Extremadura eagles.

Booted Eagle (Hieraaetus pennatus). Luna, female, on the left, and Valiente, a male, are the two Extremadura-nesting satellite-tracked birds (photos: SEO/BirdLife).

Luna is an adult female Booted Eagle nesting in Alburquerque (Badajoz). On 03.08.2011 it was fitted with a satellite transmitter to keep track of its movements thereafter. On the project website it wears the number 5. After the transmitter was fitted, it remained in its territory until setting out on its migration odyssey on 07.09.2011. On 10 September it crossed the Strait of Gibraltar and two days later reached the dreaded Sahara. There it picked up pace, putting in its two longest daily stages: 370 on 12 September and 403 km on 17 September. At last, on 19.09.2011, after a 12-day trip it reached its wintering quarters in the Sahel, over 2500 km from its nest (an average of 204 km a day). Since then, and at least until 01.03.2012, it pretty much stayed put, spending over five months in an area straddling Mauritania and Mali.

Autumn migration of six satellite-tracked Spanish Booted Eagles (Hieraaetus pennatus) in 2012 (

Valiente, wearing number 6, is an adult male Booted Eagle nesting in La Roca de la Sierra (Badajoz). It was also fitted with its transmitter on 03.08.2011 and then set out on its long journey to Africa a little later than Luna, on 13.09.2011. Like Luna it reached the Straits in three days but then needed 15 to reach the Sahel on 02.10.2011. Its pace was a bit slower (18 days, averaging 151 km a day), putting in its longest stage of 301 km on 23.09.2011. At first it settled down in Mali, 2700 km from home, but then moved southwards, first to Niger (15 October) and then to Nigeria (16 November), 3500 km from home, where it remained on 01.03.2012. Of the six Booted Eagles tracked, only one other bird wintered in two different spots, in this case reaching Sierra Leona, 3530 km from its nest. Both made the longest trips, while the other four have spent five months in the same zones.

Lastly, the third Eagle tracked, not featuring on the project website, was an adult female called Brava, from the Los Hornos Wildlife Refuge Centre (Sierra de Fuentes, Cáceres). The bird was released at Los Canchales Reservoir on 24.09.2011. It instantly flew southwards. Once at the straits it struck off over the sea but seems to have foundered somehow about 30 km northeast of Ceuta, transmitter signals ceasing on 06.10.2011.