Tern
in ornithology the popular name of any species of the genus Sterna.
They are slenderly built birds, with long, narrow, sharp-pointed wings, and forked tail, from which, as well as from their swift and circling manner of flight, they are often called sea swallows. The thick, soft, close plumage is colored light blue, black, and white, varying but little with sex, age, or season of the year. They are extensively distributed, inhabiting every zone, but prefer warm and temperate climates to the colder regions, which they only visit for a short period during the year. All are exceedingly active, and from sunrise to sunset on the wing. They walk badly and are not good swimmers, so that they are tossed about like corks.
They feed on small fish and marine animals.