The blue-billed white tern (Gygis candida) is a small tropical seabird in the family Laridae, occurring across the Indian Ocean and Pacific Ocean. Formerly treated as a subspecies within the white tern complex, conspecific with the the Atlantic white tern (G. alba) and the little white tern (G. microrhyncha), it is now generally recognised as a distinct species. First described by Johann Friedrich Gmelin in 1789, it is an all-white tern with dark eyes, a black bill with a blue base, and slaty-blue legs. Two subspecies are recognised, ranging from the Seychelles and Maldives to Hawaii and the Pitcairn Islands. Unusually, chicks occasionally fall prey to Aldabra giant tortoises in the Seychelles. This blue-billed white tern of the subspecies G. c. candida was photographed in flight at Muri Lagoon, on Rarotonga in the Cook Islands.

Photograph credit: Charles J. Sharp