The recent detection of two young Bonelli’s Eagles (Aquila fasciata) crossing the Strait of Gibraltar to Morocco (one has even crossed the Sahara desert) shows an unknown dispersive movement in this species. It is one more example that confirms the importance of North Africa to the Iberian raptors.
The Bonelli’s Eagle is usually resident across its breeding range with immature birds making sometimes large dispersions. With a few exceptions now and then, European birds are not known to cross the Strait of Gibraltar to Africa in significant numbers. Even when some birds cross the Strait, we don’t know where they disperse as they mix with the North African population.
Satellite-tracking Bonelli’s Eagles
Recently two Bonelli’s Eagles were fitted with GPS transmitter in Spain have crossed the Strait of Gibraltar to Africa. They are the first birds of this species to be tracked from Europe to Africa. The two Bonelli’s Eagles, both males, are from different origin and once in Africa they followed different paths.
The first bird know as Zahara was born in 2014 in the captive breeding centre of Bonelli’s Eagle headed by Jean-Claude Mourgues in the French department of Ardèche. The second bird known as Turón was born in 2015 in a wild nest in the province of Granada (Andalusia, Spain). Both were released in the west of the Community of Madrid, one of the reintroduction areas of LIFE Bonelli project.
Zahara: the adventurous eagle
After leaving his release site in Madrid in mid-September 2014, Zahara headed south and wondered a few days between different places in Andalusia. From his last place in Almeria, he continued south-east without stopping to cross the Strait of Gibraltar (photo above). He became the first Bonelli’s Eagle for which crossing the Strait has been able to be confirmed and followed. On 23 September, he is already in northern Morocco and in four days he arrived to Algeria and shortly after to Mauritania. Zahara continued his journey to Senegal from where he decided to return to southern Mauritania. By then he had crossed five countries and had traveled more than 4,400 kilometers (see map 1).
Turón wintered in western Morocco
After different dispersive movements in the Iberian Peninsula (first to Galicia, back to Madrid and then to Portugal and Andalusia, see map), Turón decided to head south and cross the Strait on 8 October 2015. Days later he found a suitable place to spend the winter between the Moroccan cities of Rabat and Casablanca. On his journey, Turón traveled more than 3,500 km in total similar to that Zahara (see map 2).
The full story of these Bonelli Eagles was published in the following article in Quercus magazine:
Iglesias, J.J & Álvarez, E. 2016. Sorprendentes águilas perdiceras: dos ejemplares cruzaron el Estrecho. Quercus (361): 30-33.