Chlidonias hybrida
The white-cheeked sandpiper is a graceful presence on the lakes of the Danube Delta. Unlike sea urchins, it prefers inland waters, being often seen "gathering" food from the surface of the water among water lily leaves.
In summer plumage, the crown is black and the belly is dark grey, almost black. The most striking contrast is the white cheeks, which give it its name. Bill and legs are deep blood-red. In winter the plumage becomes much paler, predominantly white-grey, with black patches on the head.
Favours lakes and marshes with abundant floating vegetation — water lilies, pondweed, frogbit. In the Danube Delta it is widely distributed, often forming mixed breeding colonies alongside the White-winged Tern (Chlidonias leucopterus) and other species.
Feeds by flying slowly at low height above the water, dipping superficially to take insects from the surface, tadpoles or small fish. Unlike sea terns, it rarely dives completely. It is a sociable bird; its colonies are often large and noisy.
Breeds colonially, constructing floating nests from stems and leaves of aquatic plants, anchored to vegetation or floating freely. The female lays 2–3 eggs, incubated by both parents for approximately 18–20 days. Stable water levels during the breeding season are critical for the survival of floating nests.
Global status is Least Concern (LC). The species depends critically on maintaining optimal water levels on lakes during the breeding season — sudden level changes destroy floating nests. The hydrological management of the Delta has a direct impact on the reproductive success of this species.