Spectacled Tern

The Spectacled Tern, known scientifically as Onychoprion lunatus, is a seabird of the Laridae family. It is a close relative of the Bridled and Sooty Terns, and was recently reclassified into the genus Onychoprion from Sterna. This species is distinguished by its grey back, contrasting with the black back of the Sooty Tern. It has white underparts and a distinctive black eye line that extends from the bill to the back of the head.

Identification Tips

When observing the Spectacled Tern, look for the characteristic grey mantle and the sharp black line through the eye, which gives the appearance of spectacles. This feature is key in distinguishing it from its relatives. The white breast and underparts are also notable identification markers.

Habitat

The Spectacled Tern is a bird of tropical oceanic islands, where it breeds and roosts.

Distribution

This tern breeds across islands in the tropical Pacific Ocean, with significant populations in the Northwestern Hawaiian Islands, particularly on Lisianski Island, and islets off Oahu. Its range extends eastward to the Tuamotu Islands and includes the Society Islands, Line Islands, Phoenix Islands, Mariana Islands, and American Samoa. There are unconfirmed breeding reports from as far south as Fiji and as far east as Easter Island.

Behaviour

The Spectacled Tern is known to be partly migratory, especially the populations from the Hawaiian Islands which travel south after the breeding season. It is believed that other Pacific populations also migrate, potentially reaching areas such as Papua New Guinea, the Philippines, and Easter Island.

Conservation status

The Spectacled Tern is currently listed as Least Concern by the IUCN, indicating that it is not at immediate risk of widespread decline.