Common Black-headed Gull
(Larus ridibundus)
Category of conservation concern (IUCN, 2020) – Least Concern
Population size: 2020: 10-99 pairs (2007: 180-250 pairs)
Distribution pattern
With isolated breeding habitats only along the Danube River (Srabarna Lake, Orsoya and the Kalomok fishponds) and in neighbouring areas (marshy area along the Ogosta River). Due to drying and other unfavourable changes in the marshes during recent years, the species no longer breeds in the traditional breeding sites such as the Belene Island. Single specimens or small flocks occur during the breeding season also at some wetlands along the Black Sea coast (Burgas wetlands, Durankulak and Shabla lakes, etc.), in the Danubian Plain, along the valleys of Struma and Maritsa Rivers, etc., but without evidence for breeding.
Population estimation for the period 2013 – 2020: During the period 2013-2020, the species was not found in four squares, where it was observed before 2013. Deterioration of some of the habitats explains their disappearance and in others, it occurred sporadically, mainly during high floods on the Danube River. New sites have been established in two squares. In the reported period, nests of the Common Black-headed Gull have been registered in the Persinski Marshes Protected Area, Kalimok Complex, Srebarna Lake, and Nova Popina Reservoir. Only in Srebarna, the species nests regularly.
Comparative distribution of the species compared to the first breeding birds atlas (Iankov, 2007): Breeding locality until 2007 | Breeding locality until 2007, confirmed after 2015 – | New breeding locality after 2015. – The breeding localities after 2015 are identified on a base of raw data from smartbirds.org.
Habitats
Breeds in marshes and lakes, over grown with reeds and club rush, with large open water surfaces covered with floating vegetation.
Trends in population changes for the period 2013-2020
Short-term trend of population size: |
Stable, with non-intermittent fluctuations |
Long-term trend of population size: |
Decreasing, with non-intermittent fluctuations |
Short-term trend of distribution: |
Stable, with non-intermittent fluctuations |
Long-term trend of distribution: |
Decreasing, with non-intermittent fluctuations |
Threats
Drainage of wetlands, changes in the water levels and in the hydrological regime of water bodies during the breeding season, disturbance.
Svilen Chesmedjiev, Petar Shurulinkov