black sea red data book - Department of Biology

Hydroprogne caspia (Pallas, 1770)
Synonyms: Sterna caspia Pallas, 1770, Hydroprogne tschedrava Lep.
Common names: Engl: Caspian Tern; Russ: Chegrava; Turk: Hazer sumrusu; Ukr:
Chegrava.
Order CHARADRIIFORMES
Family LARIDAE
Taxonomic description. Around 400-950 pairs in the region.
IUCN Status
WorldlevehLR
Black Sea Regional level: EN
Subregion level: EN
Distribution, Habitat type, Critical habitats, Limiting factors. Mostly bare shell-
covered areas on accumulative islands in brackish shallow waters and estuaries.
Numbers limited by human disturbance of the colonies and by storms.
Biology. A breeding, migratory species. Arrival in early April. Egg-laying in late
April - early May. Formed colonies recorded between the 20th and 25th of May. In
the post breeding period, birds either stay in the colony or move eastwards and
westwards. Migration to the winter grounds takes place in September-October. At
the end of October Caspian terns already occur in the Mediterranean. Colonies of
Caspian terns are always apart from other colonial birds and characterized by a high
nesting density. Its nest is a flat shallow scrab on the shell substrate. Clutch size
varies from one to three eggs. The egg-laying period is rather prolonged. If first
clutches are lost, replacements are normally laid. Under favourable conditions
breeding success is high. Exclusively ichtyophagous (sea and fresh-water fish).
Forages up to 20 km from colony, quickly responds to the mass availability of food.
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