This highly migratory New World tern frequents estuaries, coastal lagoons, river sandbars, and sandy beaches, where it attracts attention by its tiny size and buoyant flight. The adult has a black cap, white forehead, gray mantle, white underparts, yellow legs, and black on the outer primaries. The tail is short and forked. In breeding plumage, the black-tipped yellow bill is a diagnostic field mark. Identification of terns in other plumages is less straightforward: consult a good field guide.