The White-winged Tern (Chlidonias leucopterus) is a small, striking marsh tern and one of the most eagerly anticipated rarities for Swedish wetland birders each spring. It measures just 20–23 cm with a wingspan of about 63–67 cm, clearly smaller than the Common Tern and shorter-winged than the Black Tern, with a short, barely forked tail. In summer plumage the body, head and wing undersides are sooty black, while the upperwing coverts are bright white or silver-grey and the rump is white — the pale patch sits on the wing coverts rather than the flight feathers, creating a striking black-and-white contrast in flight. The bill and short legs are dark red, and winter and juvenile birds are paler, with a white underside, pale forehead and a dark patch on the back of the head.
In flocks it gives a creaking, rasping "kryke-kryke" or "kjek-kjek," harder and more metallic than the similar call of the Black Tern, though lone birds on passage are often silent. It hunts insects in a light, fluttering, low flight over water and shoreline meadows, dipping its bill to the surface or snapping prey in the air, rather than diving for fish like the larger sea terns. The species breeds in open, vegetation-rich wetlands from eastern Europe eastward through Asia and winters in Africa and southern Asia; in Sweden it is not a regular breeder but a recurring passage visitor, chiefly from May to July with a clear peak in May, and has occasionally attempted to breed alongside Black Terns. The best chances are at shallow, nutrient-rich wetlands and ponds in Skåne, on Öland and Gotland, and in Blekinge, where flocks of Black Terns are worth checking closely for this globally Least Concern rarity among them.
Read about this species in Swedish →