Polynesian Gull (Chroicocephalus utunui)
This species was described in the year 2002 on the basis of very good preserved bones, which were found on the island of Huahine.
The species was certainly once distributed through the whole Society Archipelago.
The next relatives are the Silver Gull (Chroicocephalus novaehollandiae (Stephens)) from Australia as well as the Black-billed Gull (Chroicocephalus bulleri (Hutton)), and the Red-billed Gull (Chroicocephalus scopulinus (J. R. Forster)) from New Zealand.
The species disappeared about 700 to 1200 A.D., thus shortly after the colonization of the island by Polynesians – resp., if one will trust very vague hints in a travel account from the year 1834, maybe actually as recently as during the middle of the 19th century.
Quite interesting in this context is the description of two gull species (Gavia pomarre Bruch in the year 1853 and Gavia pomare Bruch in the year 1855), which are supposed to come from the Society Islands, but which later (1887 and 1896) were identified as a juvenile Silver Gull and a juvenile Black-billed Gull, respectively.
The original material was lost during the World War II, and only drawings of the primaries and the heads (see depiction) are left.
 F. Debell Bennett: Narrative of a Whaling Voyage round the globe, from the year 1833 to 1836. Comprising Sketches of Polynesia, California, the Indian Archipelago, etc. with an account of southern whales, the sperm whale fishery, and the natural history of the climates visited. London, Richard Bentley 1840
 D. W. Steadman: A New Species Of Gull (Laridae: Larus) From An Archaeological Site On Huahine, Society Islands. Proceedings of The Biological Society of Washington Band 115: 1–17. 2002
 D. W. Steadman: Extinction and Biogeography of Tropical Pacific Birds. University Of Chicago Press 2006
the enigmatic species Gavia pomarre or Larus pomarre
Depiction from: ‘C. F. Bruch: Monographische Uebersicht der Gattung Larus Lin. Journal für Ornithologie. 1(2): 96-108. 1853’