The American herring gull or Smithsonian gull (Larus smithsonianus or Larus argentatus smithsonianus) is a large gull that breeds in North America, where it is treated by the American Ornithologists' Union as a subspecies of herring gull (L. argentatus). Adults are white with gray back and wings, black wingtips with white spots, and pink legs. Immature birds are gray-brown and are darker and more uniform than European herring gulls, with a darker tail.