Aquila pomarina (Brehm, 1831)
Aquila naevia: Elwes, Buckley, 1870: 68; Reiser, 1894, p. 114; Aquila maculata Gmelin 1788; Reiser, 1894: 114.
Conservation status: in Bulgaria: Vulnerable VU B(1a)+C, BDA-III; International: BeC-II, BoC-I, II, ECS-Spec 3, BD-I, CITES-II.
General distribution. Probably a Palearctic species whose breeding area is from the valley of the river Elbe to Byelorussia and the St. Petersburg (Russia) region, Hungary, the Balkan peninsula, Asia Minor, the Caucasus Mountains, Northern Iran, India and Northern Burma. It is mainly in SW Asia and Eastern Africa, the major migration route passing through Burgas bay, the Bosporus and Aqaba bay.
Distribution and abundance in Bulgaria. A breeding summer visitor, passage migrant and winter visitor. In the past it was common, but in the period 1950-1980 it gradually became rarer . At present, almost 50 % of its population is concentrated in the mountains Eastern Rhodopes, Sakar, the Derventski Vazvisheniya (hills) and Strandzha, about 25 % are concentrated in the mountains Eastern Balkan range and Eastern Sredna Gora, and about 15 % are in the Danube valley and along the banks of the Danube and its islands. The other 10 % are found along the northern slopes of the Rhodopes (range), Vitosha and the genuine Sredna Gora . During the autumn migration, it forms large concentrations in the region of Burgas Bay.
Habitats. Preserved forest massifs of beech, oak or mixed plantations, old field-protection belts and other forest areas, in the vicinity to vast herbaceous associations and agricultural lands that the birds use for hunting.
Biology. It mainly breeds in deciduous trees, at a height of 6-25 m. The female usually lays 2 eggs at the beginning of May, the incubation continues for 38-41 days. The young ones leave the nests at the age of about 55 days . Found in the nutrition range are the Common Vole, the Hamster, the Lizard, the Slow Worm, the Water Frog .
Similar species. The Imperial Eagle (Aquila heliaca).
Negative factors. Processing beech and mixed forests at altitudes of up to 1 000 m for wood production, infrastructure development for tourism and relaxation. Competition with the Imperial Eagle with respect to food.
Conservation measures taken. Protected according to the Biological Diversity Act. Included in the Red Data Book of Bulgaria (1985). Intensive investigations have been made on migration in the region of Atanasovsko Ezero lake .
Conservation measures needed. Preparation of a National Plan for its preservation, increase of the ecological culture of the population, provision of individual guarding for endangered nests.
References. 1. Simeonov et al., 1990; 2. Iankov, in press: 3 BirdLife International, 2004; 4. Nankinov, 1985; 5. Michev et al., 2004.
Authors: Lyubomir Profirov, Stoycho Stoychev