Gelochelidon nilotica
Easily confused with Sandwich Tern but choice of habitat usually different. Adults differs by noticeably shorter and deeper bill, lacking yellow tip. Wings are broader, tail is shorter and only slightly forked. Lacks crest. Primaries with dark trailing edge, especially underside. Rump pale grey, and there is no contrast between grey back and white tail as in Sandwich Tern. Loses the black cap in winter, but keeps a black mask (less black on head than Sandwich T). Immature birds also gives a paler impression. The back is almost uniform in colour, and the wings also have only diffuse markings. The dark trailing edge to the primaries is present though, together with dark eye mask. Rest of head is pale. Flight slightly front-heavy with shallow wing-beats. Catches insects in the air and from the ground in flight. Rarely plunge-dives. Prefers fresh water, and is often seen near wetlands, rivers and flooded fields, but also in salt water during migration.
Quite vocal and easily distinguished from most congeners. Mewing and sharp in tone, but not rattling or raucous like most terns. Most typical call is a disyllabic, mewing "ke-waat", with an upward inflection. Other variants are series of "ke-ke-ke-ke", or the mewing sounds.
Xeno-canto: map
Birdlife ecology
