Black-crowned Night Heron

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

Population size: 2020: 601-1403 pairs (2007: 1800–2500 pairs)

Distribution pattern

In single or mixed colonies, grouped or dispersed, mainly along the Danube River and its tributaries, in the Thracian Plain, along the Black Sea coast, the valley of the Arda River, and Sofia Field. In a number of areas, several colonies were observed in neighbouring squares.

Population estimation for the period 2013 – 2020: During the period 2013-2020, the species was not found in 38 squares, where it has been registered before the year 2013. Deterioration of the habitats explains the disappearance, as well as the negative trend in the breeding population of the species in the last ten years. New sites have been established in ten squares. 

Population size in Special Protection Areas of Natura 2000: 417-901 pairs (64-70% of the population). The highest numbers have been registered in the Special Protection Areas “Konush Reservoir” (180-220 pairs), in Srebarna (60-250 pairs) and in the Burgas Lake (60-120 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 on water-fringe vegetation in bogs and marshes, in alluvial and riverine forests and brush (including in groups of trees in former riverbeds or in shallow parts of dams) and rarely in broad-leaved deciduous forests. Single colonies have been found in riverbeds within the boundaries of towns, villages and industrial zones (Kardzhali, the village of Rasovo, Lom District, etc.).

Trends in population changes for the period 2013-2020

Threats

Drainage of wetlands, loss of breeding habitats, changes in the water levels and in the hydrological regime of water bodies during the breeding season, disturbance, and poaching, unregulated forestry practices.

Svilen Chesmedjiev, Vladimir Mladenov, Petar Shurulinkov