Gull-billed Tern
Gelochelidon nilotica
The Gull-billed Tern is a fairly large and powerful tern, similar in size and general appearance to a Sandwich Tern, but the short thick gull-like bill, broad wings, long legs and robust body are distinctive. The summer adult has grey upper parts, white underparts, a black cap, strong black bill and black legs.
In winter, the cap is lost, and there is a dark patch through the eye like a Forster's Tern or a Mediterranean Gull. Juvenile Gull-billed Terns have a fainter mask, but otherwise look much like winter adults.