The Yellow-billed Tern is widespread and fairly common along major river systems and in lakes east of the Andes, ranging from Colombia and Venezuela, across much of Brazil and south into Argentina. It is found singly or in pairs along river sandbanks (up to 500m), often with Black Skimmers and Large-billed Terns. During the non-breeding season, it can also be found in coastal lagoons, river mouths, and rice fields. This small tern is mostly silvery gray above and white below, with a black crown, nape and eyeline, surrounding a contrasting white forehead. It is distinguished from the Least Tern (which is more often coastal) by its heavier bill, which lacks a black tip, a shorter and less forked tail, and a broader black wedge on the upperside of the wing, formed by the outermost primaries in flight (4-5 black feathers as opposed to 2 in Leasts). Non-breeding adults have whitish crowns and lores, with black markings around the nape and auriculars. Juveniles are brown and white scalloped above and lack a solid black cap. It has a light, rapid flight and hovers frequently before diving for fish.