sooty tern

The sooty tern (Onychoprion fuscatus) is a tern in the family Laridae. It is a seabird of the tropical oceans and can fly for years at a time, skimming the sea surface for food, and returning to land only to breed, on islands throughout the equatorial zone.[3][4]

Taxonomy
The sooty tern was described by Carl Linnaeus in 1766 as Sterna fuscata, bearing this name for many years until the genus Sterna was split up; it is now classified in the genus Onychoprion as Onychoprion fuscatus.[5][6] The genus name is from ancient Greek onux, "claw" or "nail", and prion, "saw". The species name fuscatus is Latin for "dark".[7]

The sooty tern has little interspecific variation, but it is usually divided into six to eight allopatric subspecies. Some recent authors further subdivide the Indopacific population into up to eight subspecies altogether,[citation needed] but much of the variation is clinal. The affinities of eastern Pacific birds (including O. f. manutarus of Easter Island) are most strongly contested.[citation needed] Six subspecies are currently accepted by the IOC:[5]