Changes in Breeding Population Numbers ofKentish Plover Charadrius alexandrinus atAtanasovsko Lake

Atanasovsko Lake is the most important Kentish Plover breeding site in Bulgaria. 141 pairs nested there in 1978, 252 in 1979 and 238 in 1981. During the following years, numbers decreased sharply due to habitat degradation, reaching 39 pairs in 1993 and 65 in 2000. Detailed studies in 2000 showed that the first spring migrants arrived 16 March, nest-building began mid- April and egg-laying after 20 April. The latest nests with eggs were found on 15 July. The decline in numbers of the Kentish Plover breeding population at Atanasovsko Lake are due mainly to narrow watercourses, mostly dikes, becoming overgrown by tall vegetation. To a lesser degree the birds suffer from numerous ground predators, such as red foxes, jackals and feral dogs and cats. Nowadays the Kentish Plover prefers to nest where the lake is being worked, on the board-lined banks that mark out the salt production basins. Atlantic, in the Mediterranean, Black and Caspian Seas and round the Arabian Gulf. It also occurs inland in Central Asia, in the east reaching to the Trans-Baikal and Mongolia. In Bulgaria it breeds along the Black Sea coast and round the adjacent lakes, the core breeding population being concentrated mainly at Atanasovsko Lake in East Bulgaria. Atanasovsko is a shallow, hyper-saline lake divided by a motorway into northern and southern parts. The lake, being used for salt-production, is divided into numerous small ponds by a network of dikes and banks. In recent years habitat degradation has led to a serious decline in Kentish Plover numbers.

S. Y. Dalakchieva, ORNIS HUNGARICA 12-13: 1-2 (2003)