Royal Tern (Thalasseus maximus) [XC661373]
by Richard E. Webster from Laguna Manuela, Baja California, Mexico (call)
Royal Tern (Thalasseus maximus) [XC341800]
by Paul Marvin from Chincoteague National Wildlife Refuge, Accomack County, Virginia, United States (begging call)
Subspecies
Sometimes considered to form superspecies with Greater Crested Tern (Thalasseus bergii). Racial variation questionable.
The following 2 subspecies are recognised:
albididorsalis (Hartert, 1921) - Mauritania to Guinea, occasionally further S. Winters south to Namibia.
maximus (Boddaert, 1783) - Southern California to Sinaloa, and Maryland (rarely New Jersey) to Texas, and through West Indies to the Guianas and possibly Brazil, with disjunct breeding populations on Yucatán, and in southern Brazil, Uruguay and northern Patagonia. Winters south to Peru and to Uruguay and Argentina.