The lesser crested tern (Thalasseus bengalensis) is a tern in the family, Laridae. This is a medium-large tern, very similar in size and general appearance to its three very close relatives Sandwich tern, Elegant tern and Chinese crested tern. The summer adult has a black cap, black legs and a long sharp orange bill. The upperwings, rump and central tail feathers are grey and the underparts white. The primary flight feathers darken during the summer. In winter, the forehead becomes white. The call is a loud grating noise like Sandwich terns. The grey rump is a useful flight identification feature distinguishing it from the related species. The Elegant tern also differs in a slightly longer, slenderer bill, while Chinese crested tern differs in a black tip to the bill and Sandwich tern a black bill with a yellow tip. Juvenile lesser crested terns resemble same-age Sandwich terns, but with a yellow-orange bill, and paler overall, with only faint dark crescents on the mantle feathers. There are two other orange-billed terns within the range of this species, royal tern and Greater crested tern. Both are much larger and stouter-billed; royal also has a white rump and tail, while crested (which shares the grey rump) is darker overall above and has a yellower bill. See also orange-billed tern.