Greater Crested Tern

Its four or five subspecies breed in the area from South Africa around the Indian Ocean to the central Pacific and Australia, all populations dispersing widely from the breeding range after nesting. This large tern is closely related to other species in its genus, but can be distinguished by its darker, battleship-grey upperparts, white forehead even in full breeding plumage, and greenish-tinged yellow (not orange or black) bill colour.

Like all members of the genus Thalasseus, the greater crested tern feeds by plunge diving for fish, usually in marine environments; the male offers fish to the female as part of the courtship ritual.

LC

A study of an area of the Great Barrier Reef where the number of breeding great crested terns has grown ten-fold, probably due to extra food from trawl by-catch, suggested that lesser crested and sooty terns have moved away and now breed on a part of the reef where fishing is banned.

The subspecies T. b. thalassinus breeds on many islands in the Indian Ocean including Aldabra and Etoile in the Seychelles, the Chagos Archipelago, and Rodrigues.

IUCN Red List conservation status (Wikidata property P141): least concern.