Caspian tern (Sterna caspia) breeds in widely scattered locations throughout the world and winters in India and Sri Lanka and other scattered locations. The habitat of this species is large lakes, marshes, islands (in both lakes and rivers), beaches, bays, and coastal waters. Its foods are almost exclusively fishes, but it occasionally takes aquatic invertebrates, such as crayfish and insects.

This species nests on the ground on a variety of substrates, usually in open, sparsely vegetated areas. Nesting often is in colonies or in association with other ground-nesting birds such as shorebirds. The two or three (rarely one or four) eggs are incubated by both parents for twenty-five to twenty-eight days. The semi-precocial young are tended by both parents. They leave the nest after a few days and are able to fly after twenty-five to thirty days.

Description: Length: 48-56 cm. Adults in breeding plumage: A large white tern with a stout, red bill tipped with black; the complete black cap is retained for most of the breeding season and the forehead remains dusky in all plumages.