White Headed Duck
Oxyura leucocephala (Scopoli, 1769)
Anas leucocephala Scopoli, 1769: 65; Erismatura leucocephala (Scop.): Elwes, Buckley, 1870: 340; Reiser, 1894: 189; Klain, 1909: 157; Boetticher, 1927: 183.
Order Anseriformes
Family Anatidae
Conservation status: in Bulgaria: Endangered EN A[1(a+c)] + B[1a+(b(i+ii+iii+iv+v) + 2(a+b(i+ii+iii+iv)]+C[1+2(a(ii)+b)]+E, BDA-II, III (I); International: CITES-III, BeC-II, BoC-I/II, ECS-Spec 1, BD-I.
General distribution. A Palearctic species with a fragmented breeding area from Southwestern Europe and Northeastern Africa to Central Asia and China.
Distribution and abundance in Bulgaria. A winter visitor and passage migrant, mainly along the Black Sea coast. At the beginning of the 20th century, numerous during the spring migration in Atanasovsko Ezero lake [1, 2]. Observed near Sofia, in the Blagoevgrad region, in the vicinity of the cities of Plovdiv and Pazardzhik and Rozov Kladenets Reservoir, the lakes Durankulak, Beloslav, Varna and Vaya, and Burgas Bay [3, 4]. Since 1991, an increase of the numbers has been registered in the wetlands around Burgas, where at present a considerable part of the world population of the species (up to 12%) is concentrated. It is most numerous in Vaya Lake: a maxiumum of 2 260 individuals [5, 6, 7, 8]. Separate individuals and small groups are found in the lakes Pomoriysko Ezero [6], Atanasovsko Ezero [6, 9] and Shablenska Tuzla [9] and in the Varna-Belsolav Lake Complex.
Habitats. Vast freshwater basins, shore brackish and salty lagoons, sea bays, firths, artificial water basins.
Biology. Monogamous. It feeds on larvae of chironomids, water invertebrates and seeds of water plants [10, 11, 12].
Similar species. The Ruddy Duck (Oxyura jamaicensis).
Negative factors. Loss and degradation of habitats, hybridization, fishing with nets, illegal shooting, pollution of the waters.
Conservation measures taken. Protected according to the Biological Diversity Act. Included in the Red Data Book of Bulgaria (1985). The major places of concentration are declared Protected Territories, Ramsar Sites and Important Bird Areas. Prepared is a National Plan for the preservation of the species and Management Plans for the lakes Atanasovsko, Poda, Vaya, Shabla and Durankulak. Since 1996, it has been the object of special investigations and monitoring. In 2001-2002, a Balkan project for its preservation was realized.
Conservation measures needed. All habitats ought to be included in Protected Zones. Mandra Reservoir must be declared a Ramsar Site. It is necessary that restrictions are imposed on hunting in the places of concentration. Updating of the National Plan for the preservation of the species. Introduction of measures for increasing the nature preservation culture of the population around the habitats.
References. 1. Varbanov, 1912; 2. Varbanov, V. 1935; 3. Nankinov, 1985; 4. Michev, Profirov, 2003; 5. Dimitrov et al., 2000b; 6. Dimitrov et al., 2005; 7. Profirov, Dimitrov, 2001; 8. Ivanov, Jankov, 2001; 9. Michev et al., 2004; 10. Dimitrov et al., 2000a; 11. Pandourski, 2001; 12. Iankov, Ivanov, 2002.
Author: Milko Dimitrov
