The Little Tern is mainly white with a dark crown, pale grey back and upperwings. The eye is dark brown. When breeding, the bill is yellow, the crown black with a short, pointed white brow and the black eye-line reaches the bill. In non-breeding plumage, the crown is mottled with white and the bill blackish. The wing tips are two-toned grey to black on the outer primaries (flight feathers). The sexes are similar and immature birds are similar to non-breeding adults with upper wings and back mottled grey and brown. The Little Tern is also known as the Black-lored Tern, the Sea Swallow, or the White-shafted Ternlet.