Spectacled tern Spectacled tern The spectacled tern ("Onychoprion lunatus"), also known as the grey-backed tern, is a seabird in the family Laridae. A close relative of the bridled and sooty terns (with which it is sometimes confused), the spectacled tern is less common than the other members of its genus and it has been studied less. The three species, along with the Aleutian tern were recently split into a new genus "Onychoprion" from "Sterna" (Bridge "et al.", 2005). They resemble the sooty tern but with a grey back instead of a black one. Their breast and underparts are white, and they have
Arctic tern of its range. The Arctic tern was known as sea swallow describing their slender shape as they swoop over the water. The genus name "Sterna" is derived from Old English "stearn", "tern". The specific "paradisaea" is from Late Latin "paradisus", "paradise". The Scots names "picktarnie", "tarrock" and their many variants are also believed to be onomatopoeic, derived from the distinctive call. Due to the difficulty in distinguishing the two species, all the informal common names are shared with the common tern. The Arctic tern has a continuous worldwide circumpolar breeding distribution; there are no recognized subspecies. It can be found