Gull-billed Tern

The gull-billed tern is a fairly large, powerful tern, 33–42cm long with a wingspan of 76–91cm, similar in size to a Sandwich tern but with a short, thick, gull-like bill, broad wings, long legs and a robust body. The summer adult is grey above and white below with a black cap and strong black bill and legs. In winter the cap is lost, leaving a dark patch through the eye, and juveniles look much like winter adults. Its call is a characteristic ker-wik (Wikipedia, general species account).

Unlike most white terns it does not normally plunge-dive for fish. It feeds more like a marsh tern, largely on insects caught in flight, and has a broader diet than most terns. It breeds in colonies on lakes, marshes and coasts, laying two to five eggs in a ground scrape, and northern breeders migrate south for the winter (Wikipedia, general species account).