South American Tern

Overview

The South American tern (Sterna hirundinacea) is a species of tern found in coastal regions of southern South America. It is generally the most common tern in its range and is larger than either the common or Arctic terns.

Identification

• Length of 40 to 44 centimetres, making it larger than the common tern and Arctic tern.
• Red beak in adults that is larger than that of similar species, with no dark bar on the wing carpus.
• Black cap extending below the eye, usually separated by a white crescent with a neatly defined rear edge.
• Juveniles feature boldly barred, dusky upper parts and retain barred tertials into immature plumage.

Habitat

Found around the coasts of the southern half of South America, including the Falkland Islands, ranging north to Peru and Brazil. Breeding ranges extend along the Atlantic coast from east central Brazil to Tierra del Fuego and the Pacific coast of southern Peru and Chile.

Diet

Feeds on fish, crustaceans and other small invertebrates. It nests on islands, beaches and cliff tops, and when not breeding, may be seen offshore, in estuaries and harbours.

Did you know?

An 1877 account described a breeding colony in Chubut Province, Argentina, with an estimated 135,000 nesting birds, causing it to be difficult walking between nests without crushing eggs.