Whooper Swan
Cygnus cygnus Linnaeus, 1758
Cygnus musicus: Hristovich, 1892: 424; Reiser, 1894: 181; Klain, 1909: 143.
Order Anseriformes
Family Anatidae
Conservation status: in Bulgaria: Endangered EN=D (2), BDA-III; International: BeC-II, BoC-II, III.
General distribution. A Palearctic species whose breeding area embraces Iceland, the Scandinavian countries and Northern Russia. It is also found in Asia, Canada and USA. It winters at places almost throughout Europe in numbers of up to 65 000 individuals, which is more than 50% of the concentration of its world population [1].
Distribution and abundance in Bulgaria. Passage migrant and winter visitor mainly around the large water basins along the Black Sea coast: the Southern one (an average of 68 and a maximum of 444) and the Northern one (an average of 138 and a maximum of 554); within the country it is less numerous; the maximum numbers registered for the country are 1 107 individuals in 1997 [2]. The largest concentrations were registered around Mandrensko Ezero lake: over 1 000 individuals [3]. The total wintering population is estimated at about 500 individuals [5].
Habitats. Shore brackish or salty lakes, sea shallows, arable lands, pastures.
Biology. In Bulgaria it mainly feeds on winter sown fields close to large non-freezing water basins, where it spends the nights [4].
Similar species. Bewick's Swan (Cygnus columbianus bewickii).
Negative factors. Eutrophication of the wetlands, illegal shooting, pollution of the soils by agriculture, predators.
Conservation measures taken. Protected according to the Biological Diversity Act; intensive studies carried out on its migration and wintering [2, 3]; some habitats along the Black Sea coast – the lakes Durankulak, Shabla, Pomoriysko, Atanasovsko, Vaya (part of it) and the Poda locality are declared Protected Territories and Ramsar Sites [5].
Conservation measures needed. Preparation of a National Plan for its preservation; increase of the ecological culture of the population; declaration of the Mandrensko Ezero lake and the shore meadows Protected Localities.
References. 1. BirdLife International, 2004; 2. Michev, Profirov. 2003; 3. Dimitrov et al., 2005; 4. Nankinov et al., 1997; 5. Profirov, Michev (Eds), 2003.
Author: Lyubomir Profirov
