The ring-billed gull (Larus delawarensis) is a medium-sized gull. The genus name is from Latin Larus which appears to have referred to a gull or other large seabird. (The specific delawarensis refers to the Delaware River.) The ring-billed gulls' breeding habitat is near lakes, rivers, or the coast in Canada and the northern United States. They nest colonially on the ground, often on islands. This bird tends to be faithful to its nesting site, if not its mate, from year to year.