Caspian tern

The Caspian tern is the world's largest species of tern, with a scattered, near-worldwide distribution, and is monotypic within its genus Hydroprogne, with no recognized subspecies. The genus name combines the Ancient Greek for water with the Latin for swallow, and the species name refers to the Caspian Sea. It is a substantial seabird, 48 to 60 centimeters long with a 127 to 145 centimeter wingspan and weighing 530 to 782 grams, with black legs, a long thick red orange bill with a small black tip, a white head with a black cap, white neck and underparts, pale grey upper wings with dark primary feathers, and a tail less forked than in other terns; its call is a loud heron like croak. Its breeding habitat spans large lakes and ocean coasts across North America, including the Great Lakes, Europe's Baltic and Black Seas, Asia, Africa and Australasia, and North American birds migrate to southern coasts and the West Indies while European and Asian birds winter in Old World tropics. The global population is estimated at about 50,000 pairs, with Baltic populations of particular conservation concern.