Medium-sized tern found on open ocean, beaches, and large lakes. Adults have red bill with black tip, pale gray body, and black cap. First-years show only partial black cap on back of neck, dark outer primaries, and dark shoulder. Similar to Forster's, Arctic, and Roseate Terns. Separated from breeding Forster's Tern by entirely gray upperwings; nonbreeding Forster's shows black ear patch. Somewhat longer billed and shorter tailed than Arctic Tern with paler body. Shorter tailed and overall darker than gleaming white Roseate Tern. Often found in large flocks, especially in late summer. Gives a harsh screeching call "KEEE-yurrrr."