Black Tern

(Chlidonias niger)

Category of conservation concern (IUCN, 2020) – Least Concern

Population size: 2020: 0-100 pairs (2007: 24-50 pairs)

Distribution pattern

With small numbers of dispersed breeding sites, mainly in the wetlands along the Danube River and the neighbouring areas of the Danubian Plain. Summering or non-breeding individuals have been observed with low degree of reliability for breeding in the Sofia Field and the Thracian Plain, and along the valley of the Struma River, the Black Sea coast and the Danubian Plain.

Population estimation for the period 2013 – 2020: During the period 2013-2020, the species was not established in one square, where it was found before 2013. New localities were established in six squares.

Population size in Special Protection Areas of Natura 2000: 0-84 pairs (84% of the population). The highest numbers have been registered in the “Kalimok Complex” SPA (0-48 pairs).

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 other water bodies with standing fresh waters (fishponds, temporary spills, etc.), breeding on floating aquatic vegetation in the open parts of the water bodies (close to water fringe vegetation).

Trends in population changes for the period 2013-2020

Threats

Drainage of wetlands, changes in the water level and in the hydrological regime of water bodies during the breeding season, disturbance.

Svilen Chesmedjiev, Petar Shurulinkov