The Royal Tern is a large, orange-billed tern which is found only along ocean beaches.
Both a non-breeding adult and a juvenile have a white forehead and a narrow, shaggy band around the back of the head. 
A breeding adult has a complete black cap.
A juvenile Royal Tern is similar to a non-breeding adult, but its bill is smaller and pale yellow instead of orange.

Naples Pier, Naples, Florida, USA, 21 November 2012