Gull-billed Tern
Gelochelidon nilotica

The Gull-billed Tern, named for its bill, which is thicker and blunter than many other terns, occurs over much of the world and can be found in coastal and inland areas of Australia. They are of a similar size to the Silver Gull at 35-38 cm. The bird pictured here is in breeding plumage, which consists of a black cap, whereas non-breeding birds have a black eyeptach only.
 

1-3: Cairns Esplanade, Qld, 13/10/2011.