CASPIAN TERN(Hydroprogne caspia) – (See images below)
DESCRIPTION: The Caspian Tern has a black cap that extends to the eyes 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. The legs are black and the bill is red with a black tip. In non-breeding adults the head is greyish. Juveniles are mottled grey or have brown streaks, with dark orange legs. Sexes are similar. This is the largest tern at some 54 cm (22 inches) long.
NAME: The name ‘Caspian’ refers to the Caspian Sea, where the first specimen was found. The name ‘Tern’ is from Old Norwegian ‘taerne’ for this species. The Latin genus name ‘Hydroprogne’ is from Greek and refers to a ‘water swallow’, in reference to the flight behavior of this tern.
HABITAT: Near fresh or saltwater, such as marshes, small islands, coastal lagoons.
DIET: Fish for the most part, which they catch by diving from the air.
NESTING: The Caspian tern breeds in colonies on the ground of small islands in estuaries or coasts, and nesting birds are easily disturbed. About two beige eggs are laid, which are incubated by both parents. They will feed the chicks for several months, including when they can fly on their own.
DISTRIBUTION: The current breeding range of the Caspian tern includes widespread areas around the world, notably Australasia, Europe, Asia, and North America. That range has expanded north in the last few decades, and the trend appears to be related to climate change. The species migrates south of its breeding range to Africa or South America. Occasionally some vagrants (see note below on bird vagrancy) will spend the winter on Hawaii. Some local populations are year-round residents.
ON PEI: Does not breed on Prince Edward Island, but common in the summer and fall, and uncommon in the spring.
CONSERVATION: The fish diet of this tern apparently can cause a problem when colonies nest near salmon runs on the West Coast. 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’.
Vagrancy: In biology this means an animal going way outside its normal range. For birds, this can happen when there are storms and they get blown off course. On other times, the bird simply wanders in a different direction than usual. Here’s an article about vagrancy in birds.
SIMILAR SPECIES: Royal Tern, Elegant Tern, Common Tern, Arctic Tern
Caspian Tern (.pdf document, Alaska Fish and Wildlife Service)

Caspian Tern near Beach Point, PEI - Sept. 10, 2017 - © Chris Rice
Caspian Tern near Beach Point, PEI. The bird has some seaweed on its wing – Sept. 10, 2017 – Chris Rice
Caspian Tern with meal - near Beach Point, PEI - Sept. 10, 2017 - © Chris Rice
Caspian Tern with meal – near Beach Point, PEI – Sept. 10, 2017 – Chris Rice
Caspian Tern - Cobourg, ON - Apr. 2007 - photo by Mdf
Caspian Tern – Cobourg, ON – Apr. 2007 – photo by Mdf