Aleutian Terns (Onychoprion aleuticus, formerly Sterna aleutica)

The Aleutian Tern (Onychoprion aleuticus, formerly Sterna aleutica – see Bridge et al., 2005) is a seabird..

Distribution / Range

This tern species breeds in colonies on coasts and islands in Alaska and easternmost Siberia. It is strongly migratory, wintering off Indonesia and Malaysia. Large numbers appear off China during passage periods.

It is a very rare vagrant to western Europe, with just one record, on the Farne Islands off Northumberland, England on 28 – 29 May 1979.

Description

This medium-sized tern has a short, pointed bill and a long, deeply forked tail. It has a black cap with a white forehead, dark gray mantle and underparts and a mostly pale underwing with a dark secondary bar. It has a white rump and tail, black legs and a black bill.

Breeding / Nesting

The average clutch consists of 2-3 eggs placed in a ground scrape. It sometimes nests among Arctic Terns, which, like most white terns, are fiercely defensive of their nest and young and will attack large predators.

Diet / Feeding

Like most other terns, the Aleutian Tern feeds by plunge-diving for fish, usually from saline environments. The offering of fish by the male to the female is part of the courtship display.

Calls / Vocalizations

Its call is described as musical whee-hee-hee.