Haliaeetus albicilla (Linnaeus, 1758)
Conservation status: in Bulgaria: Vulnerable VU=[B2+c(i, iii)], BDA-II, III; International: IUCN-NT, CITES-I, BeC-II, BoC-II, ECS-Spec 1, BD-I.
General distribution. A Palearctic species with a scattered breeding area in Europe and Asia.
Distribution and abundance in Bulgaria. Resident, with wintering of young birds mainly in the more northern regions (the Danube Delta). In the past, it often bred near the Danube, the Black Sea coast and the valleys of the large rivers. In the second half of the previous century, the number of breeding pairs abruptly diminished. In the 1980s, only 1 pair bred on Belene Island [1, 2]. Later the breeding population was estimated at 2-6 pairs . Since the beginning of the 1990s, a slow restoration of the population has been observed, mostly along the Danube (at present at least 12 pairs, 6 of which on Bulgarian territory). Along the Black Sea coast, there are only 3 pairs for now. A novelty is the staying of a pair within the country, near Ivaylovgrad Reservoir. The total number of breeding and potentially breeding pairs is 11 . In the winter, the numbers increase at the expense of wandering and settling young birds, mainly from the delta of the Danube; these fluctuate probably between 30 and 40 individuals. In January 2005, along the Danube between the town of Somovit and the city of Silistra, 25 birds were registered .
Habitats. Coasts of seas, rivers and lakes rich in fish and water birds, with trees that are high and comfortable for nesting. In the winter also in places around artificial water basins – reservoirs, fish farms, etc.
Biology. The pair has several nests built mainly on white poplar trees, that it changes during the separate years. In March, the female lays 1-3 eggs. Incubation continues for 38-42 days. The young ones remain in the nest for 80-90 days. It feeds on fish, water birds, small mammals, etc. .
Similar species. None.
Negative factors. In the past, direct persecution and killing; placing poisonous baits for predatory mammals; felling trees along the Danube islands, continuing to the present day.
Conservation measures taken. Protected according to the Biological Diversity Act. Included in the Red Data Book of Bulgaria (1985). Some of the breeding places are in the reserves Kamchiya and Ropotamo and in Belene Natural Park.
Conservation measures needed. Change in the forestry practice on the islands and the shores of the Danube, as felling large white poplar trees is a significant factor for the preservation of the species.
References. 1. Red Data Book of Bulgaria (1985); 2. Simeonov et al., 1990; 3. Kostadinova, 1997; 4. Ivanov, in press.
Authors: Bozhidar Ivanov, Dimitar Georgiev, Milko Dimitrov, Boris Barov