Южноамериканская крачка Sterna hirundinacea

Medium-sized tern, mostly restricted to coastal areas. In breeding plumage, strikingly pale gray above and below with an extensive black cap, and an unmarked red bill and legs. The tail reaches beyond the wing tips when at rest. Wings are uniformly pale gray with no black. Nonbreeding birds have a half hood. Juveniles are mottled brown on the back.