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Caspian tern

Caspian tern
Sterna-caspia-010.jpg
breeding plumage
Canada
Caspian tern (Hydroprogne caspia) non-breeding.jpg
non-breeding plumage
Gambia
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Sternidae
Genus: Hydroprogne
Kaup, 1829
Species: H. caspia
Binomial name
Hydroprogne caspia
(Pallas, 1770)
Synonyms

Sterna caspia
Hydroprogne tschegrava
Helopus caspius


Sterna caspia
Hydroprogne tschegrava
Helopus caspius

The Caspian tern (Hydroprogne caspia, formerly Sterna caspia) is a species of tern, with a subcosmopolitan but scattered distribution. Despite its extensive range, it is monotypic of its genus, and has no accepted subspecies. The genus name is from Ancient Greek hudros, "water", and Latin progne, "swallow". The specific caspia is from Latin and, like the English name, refers to the Caspian Sea.

It is the world's largest tern with a length of 48–60 cm (19–24 in), a wingspan of 127–145 cm (50–57 in) and a weight of 530–782 g (18.7–27.6 oz). Adult birds have black legs, and a long thick red-orange bill with a small black tip. They have a white head with a black cap and white neck, belly and tail. The upper wings and back are pale grey; the underwings are pale with dark primary feathers. In flight, the tail is less forked than other terns and wing tips black on the underside. In winter, the black cap is still present (unlike many other terns), but with some white streaking on the forehead. The call is a loud heron-like croak.

Their breeding habitat is large lakes and ocean coasts in North America (including the Great Lakes), and locally in Europe (mainly around the Baltic Sea and Black Sea), Asia, Africa, and Australasia (Australia and New Zealand). North American birds migrate to southern coasts, the West Indies and northernmost South America. European and Asian birds spend the non-breeding season in the Old World tropics. African and Australasian birds are resident or disperse over short distances.


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Wikipedia

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