Little Tern
Sterna albifronsPallas, 1764
Order Charadriiformes
Family Sternidae
Conservation status: in Bulgaria: Endangered EN=A{2 (a +c)+3 (b+c)+4 (a+c)+B{1 (a+b (i+ii+iii+iv)+C{1(a (i)} + E, BDA-II, III; International: BeC-II, BoC-II, BD-I.
General distribution. A cosmopolitan species. The breeding area embraces Europe (without the northern parts), Front, Central, Southern and Southeastern Asia, Northern and Western Africa, the coasts of Northern America, the islands of the Caribbean basin and the eastern coast of Australia.
Distribution and abundance in Bulgaria. A breeding summer visitor and passage migrant. At the end of the 19th until the middle of the 20th century, it was numerous along the Danube and in the lakes Shabla and Durankulak [1, 2, 3, 4, 8, 9, 13]. At present, the major breeding population in the country is concentrated in the Burgas wetlands: the lakes Atanasovsko, Pomoriysko and in the Poda locality [12], where in 2003 there were 7 and in 2004 10 breeding pairs (A. Kovachev, personal communication). In 1993-1995 4-8 pairs bred in Uzungeren Lake (K. Bedev, unpublished data). A new breeding habitat is the oxygenation lakes of LUKOIL near Burgas, where 13-26 pairs bred in 2003-2006 (K. Bedev, unpublished data). There are up to 10 breeding pairs along the Danube and the lakes Durankulak and Shabla [10]. The breeding population is estimated at 100-160 breeding pairs [5, 6, 7, 10, 11].
Habitats. Freshwater, brackish and supersalty wetlands. Outside the multiplication period it wanders along lakes, marshes, slow-flowing rivers, saltworks, etc.
Biology. It breeds in independent colonies or in the periphery of mixed colonies with the Common Tern and the Collared Pratincole. The nest is in a hole in the ground and is covered with mussels, water plants and grasses. The full clutch has 2-3 eggs with an oval shape coloured with black spots and dots. Ichthyophagous.
Similar species. The Common Tern (Sterna hirundo).
Negative factors. Flooding of the breeding colonies; destruction of the clutches and of the nests with young birds by ground predators; disturbance; destruction or overgrowing of the breeding places; flooded areas by oil products.
Conservation measures taken. Protected according to the Biological Diversity Act. The major breeding places are in Protected Territories.
Conservation measures needed. Regulation of the numbers of ground predators in the areas of breeding. Building alluvial islands and artificial sand bars in the lakes Atanasovsko and Pomoriysko, the Poda locality and the oxygenation lakes of LUKOIL. Discontinuation of the repair activities in the region of breeding along the dikes in Pomorie and Burgas saltworks.
References. 1. Botev, 1985; 2. Georgiev, 1976; 3. Donchev 1980; 4. Donchev 1984; 5. Kostadinova, 1997; 6. Nankinov et al., 2004; 7. Nankinov, Simeonov, Michev, Ivanov, 1997; 8. Patev, 1950; 9. Prostov, 1964; 10. Iankov, 2006; 11. BirdLife International, 2004; 12. Dimitrov, 2005; 13. Reiser, 1894;
Authors: Kiril Bedev, Milko Dimitrov
