CASPIAN TERN – (Hydroprogne caspia)
The Caspian Tern is the largest tern, at some 54 cm (22 in.) long, and is easily recognizable from its black cap in breeding adults. The body is white except for the back and most of the wings, which are light grey. The wing tips are black on the underside. The tail lacks the typical fork shape of other terns, which helps in identification. The legs are black and the bill is red with a black tip. In nonbreeding adults the head is greyish. Juveniles are mottled grey or have brown streaks, with dark orange legs. Sexes are similar.
The Latin name of this tern species, ‘Hydroprogne’, means ‘to swallow water’, and ‘Caspian’ refers to the Caspian Sea, where the first specimen was found.
The diet of this tern species is made almost entirely of fish, which they catch by diving from the air. This diet apparently can cause a problem when colonies nest near salmon runs on the West Coast.
The Caspian tern breeds on the ground on small islands in estuaries or coasts, and nesting birds are easily disturbed. The Caspian tern does not breed on PEI but is fairly common in the summer, common in the fall and uncommon in the spring. Its current breeding range includes widespread areas around the world, notably Australasia, Europe, Asia, and North America. Their breeding range has expanded north in the last few decades, which appears to be related to climate change. It migrates south of its breeding range to Africa or South America. Some local populations are year-round residents.
Conservation: Caspian tern numbers have declined in some areas but increased in others, so at the present it still is considered as a species of ‘least concern’.