Atlas of nesting birds in Bulgaria

Squacco Heron

(Ardeola ralloides)

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

Population size: 2020: 87-417 pairs (2007: 300–650 pairs)

Distribution pattern

Relatively rare breeding species with a small population. Dispersed and grouped along the Danube bank, the middle and lower reaches of the rivers Ogosta, Iskar, Vit, Yantra, Maritsa, Tundzha and Arda and the large lakes along the Black Sea coast (the Varna-Beloslav Lake Complex and the Burgas Wetlands). Confirmed, but incidental-breeding site is registered in the Sofia Field (located in the highest altitude for the country).

Population estimation for the period 2013 – 2020:  During the period 2013-2020, the species was not found in 20 squares, where it was established before the year 2013. Deterioration of the habitats explains their disappearance, but in most of these squares, the species were found with low degree of reliability for breeding. New breeding sites have been established in four squares.

Population size in Special Protection Areas of Natura 2000: 57-310 pairs (35-74% of the population). The highest numbers are found in the Special Protection Areas “Srebarna” (30-100 pairs), “Burgas Lake” (0-100 pairs) and “Belene Islands Complex” (19-35 pairs).

Big size map

Breeding distribution 2013 – 2020 – The distribution and the estimation of the population size of the species for the period 2013 – 2020 is presented –

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 mainly in bogs and marshes (water-fringe vegetation), less often in alluvial and riverine forests and brush.

Trends in population changes for the period 2013-2020

Short-term trend of population size:

Stable

Long-term trend of population size:

Decreasing

Short-term trend of distribution:

Stable

Long-term trend of distribution:

Decreasing

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, poaching, illegal logging, and unregulated forestry practices. 

Svilen Chesmedjiev, Kalin Velev, Petar Shurulinkov