Royal Terns, Seagulls + Black Skimmer. The Royal Tern (Thalasseus maximus, aka Sterna maxima) is a seabird in the tern family Sternidae. This bird has two distinctive subspecies. T. m. maximus breeds on the Atlantic and Pacific coasts of the southern USA and Mexico into the Caribbean. The slightly smaller T. m. albididorsalis breeds in coastal west Africa. American birds winter south to Peru and Argentina, and African breeders move both north and south from the breeding colonies. The Black Skimmer, Rynchops niger, is a tern-like seabird, one of three very similar birds species in the skimmer family. It breeds in North and South America. Northern populations winter in the warmer waters of the Caribbean and the tropical and subtropical Pacific coasts, Reference: Wikipedia.