Tern

Tern, a book-name for any bird of a sub-family (Sterninae) of Gulls distingnished by their small size, long pointed wings, and long and usually forked tail. There are many species universally distributed. From their swift circling flight and their forked talls they are often called Sea-swallows. They feed on small fish and other marine animals, taking their food on the wing. The Common Tern (Sterna fluviatilis) is British.