Osprey
Pandion haliaetus Linnaeus, 1758
Falco halia¸tus Linnaeus, 1758; Hartert, 1910-1922, 2: 1191.
Order Falconiformes
Family Pandionidae
Conservation status: in Bulgaria: Critically endangered CR=[A2(a+c) + B1(a+b) + 2a + D], BDA-III; International: IUCN-VU, CITES-I, BeC-II, BoC-I, II, ECS-Spec 1, BD-I.
General distribution. A cosmopolitan monotypical species. It breeds in Europe, Asia, America, Northern Africa, Australia. The northern populations are migratory.
Distribution and abundance in Bulgaria. A breeding summer visitor and passage migrant. In the past, 31 habitats were known from the breeding period, whereby a total of about 10-20 pairs "remained" in the country [1, 5]. Today it is found in a restricted and non-permanent number of habitats. There are data about 3 cases of certain breeding (Ivaylovgrad Reservoir, Pyasachnik Reservoir, Aleko Konstantinovo fish arms) [2] and 5 of very probable breeding (near the village of Hadzhidimovo, a microreservoir near the village of Brezovo, Plovdiv region, Asenovtsi Reservoir, Sliven region, Ticha Reservoir [2] and Belene Island [3]. The total abundance of the species in the country is estimated at 3-6 [2], and 10 breeding pairs [5].
Habitats. Various natural and artificial wetlands with stagnant or flowing waters. A basic requirement with respect to the habitat is the presence of considerable food resources (mainly fish) in combination with appropriate places for breeding (old trees in flooded forests, poles of power lines, etc.). When looking for food it goes away at distances of up to 10-20 km [4].
Biology. In Bulgaria it is unstudied. Breeding starts at the age of 3-6 years. It nests singularly, mainly using trees, in some cases rocks and artificial facilities (including poles of high-voltage lines). It lays 2-3 eggs from the second half of April to the beginning of May. The incubation period is 34-40 days. Until the autumn migration, the young birds are bound to the adults. It migrates on a large scale. It feeds exclusively on fish [4].
Similar species. None.
Negative factors. Destruction and/or degradation of habitats; poaching, illegal shooting during migration and the breeding period (in fish farms); disturbance by fishermen, hunters, tourists, etc. (it is especially sensitive to human presence); reduction of the fish reserves (in the larger water basins in the country); felling of old trees near the water basins. A great risk of collisions and/or shortcuts with high voltage power lines.
Conservation measures taken. Protected according to the Biological Diversity Act, included in the Red Data Book of Bulgaria (1985); some of its habitats (Belene Island) fall withing protected territories.
Conservation measures needed. Determination of certain habitats; guarding of vulnerable nests during the breeding season; declaring the places with certain breeding habitats protected; increase of the ecological culture of the population. Attraction by artificial nests to places that are suitable for the species. Improvement of the effectiveness of the nature protection legislation by a considerable increase of the size of the sanctions.
References. 1. Nankinov, 1985; 2. Iankov, in press; 3. T. Michev, in press; 4. Cramp, 1980; 5. Nankinov, 1998.
Author: Dimitar Gradinarov
