Claudio Contreras / Royal Tern (Thalasseus maximus), El Requeson, Gulf of California, Baja California Peninsula, Mexico, December.

Nick Garbutt / King Penguin (Aptenodytes patagonicus) displaying at hovering Antarctic Tern (Sterna vittata) Beach front, Salisbury Plain, South Georgia, South Atlantic. January

LYNN M. STONE / Royal terns {Thalasseus maximus} Florida, USA.

Claudio Contreras / Royal Tern (Thalasseus maximus) in flight El Requeson, Gulf of California, Baja California Peninsula, Mexico, December.

Claudio Contreras / Double-Crested Cormorant (Phalacrocorax auritus), Royal Tern (Sterna maxima) and tourists canoeing in background, El Requeson, Gulf of California, Baja California Peninsula, Mexico, December. (Digital...

Claudio Contreras / Royal Tern (Thalasseus maximus) vocalising to another in flight, El Requeson, Gulf of California, Baja California Peninsula, Mexico, December.

Robin Chittenden / Royal tern (Thalasseus maximus) in flight, Western Division, Gambia, March

Juan Carlos Munoz / Royal Tern (Thalasseus / Sterna maximus) portrait. Everglades National Park, Florida, USA, February.

Tom Vezo / Royal Tern (Thalasseus maximus) flying, Rio Grande Valley, Texas

LYNN M. STONE / Royal Tern (Thalasseus maximus) in flight, with Scaled Sardine, which it will offer to a female as part of courtship behavior. Gulf of Mexico beach, St. Petersburg, Florida, USA, April.

LYNN M. STONE / Royal Terns (Thalasseus maximus) stepping toward and then around each other in courtship ritual. Gulf of Mexico beach, St. Petersburg, Florida, USA, April.

LYNN M. STONE / Royal Terns (Thalasseus maximus) in breeding plumage performing courtship behavior. Gulf of Mexico beach, St. Petersburg, Florida, USA, April.

LYNN M. STONE / Royal Tern (Thalasseus maximus) in breeding plumage, in flight with Scaled Sardine 'offering' for female, as part of courtship. Gulf of Mexico beach, Pinellas County, Florida, USA, April.

LYNN M. STONE / Royal Tern (Thalasseus maximus) in breeding plumage, wings spread, Gulf of Mexico beach. Pinellas County, Florida, USA, April.

LYNN M. STONE / Royal Tern (Thalasseus maximus) in breeding plumage, in flight with Scaled Sardine offering for a female. Gulf of Mexico beach, Pinellas County, Florida, USA, April.

LYNN M. STONE / Royal Tern (Thalasseus maximus) in breeding plumage, with Scaled Sardine 'offering' to a female as part of courtship. Black Skimmers are in the background. Pinellas County, Florida, USA, April.

LYNN M. STONE / Royal Terns (Thalasseus maximus) in breeding plumage performing courtship. Pinellas County, Florida, USA, April.

Kevin Schafer / Royal Tern (Thalasseus maximus) displaying, Los Haitises National Park, Dominican Republic

Kevin Schafer / Royal Tern (Thalasseus maximus) trio displaying, Los Haitises National Park, Dominican Republic

Steve Gettle / Royal Tern (Thalasseus maximus) flying, Fort Desoto Park, Florida

David Tipling / Royal tern (Thalasseus maximus) resting with head under wing, Sanibel island, Florida, USA

Bernard Castelein / Royal tern (Thalasseus maximus) Sanibel Island, Florida, USA

Suzi Eszterhas / Royal Tern (Thalasseus maximus) perching on post, Elkhorn Slough, California

Suzi Eszterhas / Royal Tern (Thalasseus maximus) perching on post, Elkhorn Slough, California

Gerrit Vyn / A lightly oiled Royal Tern (Thalasseus maximus) fledgling on the beach waiting to be fed. The bird was oiled as a result of the BP Deepwater Horizon oil leak in the Gulf of Mexico. Raccoon Island, Ter...

Gerrit Vyn / Flock of Royal Tern (Thalasseus maximus) oil covered fledglings wait to be fed in a nesting colony on Queen Bess Island. These birds have little chance of survival as their feathers are too damaged, a...

Gerrit Vyn / Royal Tern (Thalasseus maximus) juvenile oiled and waterlogged, as a result of the BP Deepwater Horizon oil leak, drowning in waters adjacent to a nesting colony on Queen Bess Island. Barataria Bay ar...

Gerrit Vyn / Royal Tern (Thalasseus maximus) juvenile oiled and waterlogged, as a result of the BP Deepwater Horizon oil leak, drowning in waters adjacent to a nesting colony on Queen Bess Island. Barataria Bay ar...

Barry Mansell / Royal terns (Thalasseus maximus) adults and chicks, on beach, Talbot Island State Park, North Florida, USA

Barry Mansell / Flock of Royal Tern (Thalasseus maximus) with chicks, Talbot Island State Park, Florida, USA

Barry Mansell / Royal Tern (Thalasseus maximus) adult and chick, Talbot Island State Park, Florida, USA

Barry Mansell / Royal Tern (Thalasseus maximus) Talbot Island State Park, Florida, USA

Barry Mansell / Royal Tern (Thalasseus maximus) in flight, carrying food for chicks, Talbot Island State Park, Florida, USA

Barry Mansell / Royal Tern (Thalasseus maximus) in flight, Talbot Island State Park, Florida, USA

Claudio Contreras / Royal tern (Thalasseus maximus) calling, Rasa Island Special Biosphere Reserve, Sea of Cortez (Gulf of California) Mexico, April

Claudio Contreras / Royal tern (Thalasseus maximus) pair greeting each other, Rasa Island Special Biosphere Reserve, Sea of Cortez (Gulf of California) Mexico, April

Claudio Contreras / Royal tern (Thalasseus maximus) pair, post-mating dance, Rasa Island Special Biosphere Reserve, Sea of Cortez (Gulf of California) Mexico, April

Claudio Contreras / Royal tern (Thalasseus maximus) in flight, Scammon's Lagoon, Vizcaino Biosphere Reserve, Baja California Peninsula, Mexico, March

Rob Tilley / Royal tern {Thalasseus maximus} head profile portrait, Naples, Florida, USA

Nick Garbutt / Royal Tern (Thalasseus maximus) colony at St Catherine's Point, Loango National Park, Gabon, Central Africa

Nick Garbutt / Royal Tern (Thalasseus maximus) colony in flight, St Catherine's Point, Loango National Park, Gabon, Central Africa

Winfried Wisniewski / Royal Tern (Thalasseus maximus) pair, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) pair courting, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) displaying, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) flying, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) immature flying, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) flying, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) pair in breeding plumage, Florida

Winfried Wisniewski / Royal Tern (Thalasseus maximus) pair in breeding plumage, Florida

Scott Leslie / Royal Tern (Thalasseus maximus) portrait, Lover's Key, Fort Meyer's Beach, Florida

Theo Allofs / Royal Tern (Thalasseus maximus) calling, Fort Myers Beach, Florida

Rob Tilley / Royal Tern {Thalasseus maximus} head portrait, Sanibel, Florida, USA

Tom Vezo / Royal Tern (Thalasseus maximus) trio flying over water, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) pair in food exchange part of courtship display, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) pair in courtship display, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) pair in courtship display, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) pair on beach, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) trio interacting on beach, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) flying with fish prey, Rio Grande Valley, Texas

Tom Vezo / Royal Tern (Thalasseus maximus) flying over ocean, Rio Grande Valley, Texas

Rolf Nussbaumer / Royal Tern (Thalasseus maximus) with winter plumage, about to take off, Sanibel Island, Florida, USA. December 1998

Tom Vezo / Royal Tern (Thalasseus maximus) pair mating on beach, South Padre Island, Texas

Dietmar Nill / Flock of Royal terns {Thalasseus maximus} on beach, Gambia.

Chris Gomersall / Royal terns mating {Thalasseus maximus}

Pete Oxford / Royal Terns {Thalasseus maximus} San Pablo Beach, Guayas, Ecuador

Pete Oxford / Royal Terns {Thalasseus maximus} and Gray / Grey-hooded Gulls {Larus cirrocephalus} San Pablo Beach, Guayas, Ecuador

Pete Oxford / Royal Terns {Thalasseus maximus} San Pablo Beach, Guayas, Ecuador

Pete Oxford / Royal Tern {Thalasseus maximus} San Pablo Beach, Guayas, Ecuador

LYNN M. STONE / Royal tern {Thalasseus maximus} Florida, USA.

TOM MANGELSEN / Royal Terns nesting colony, Gulf coast Louisiana, USA. (Thalasseus maximus)

Barry Mansell / Royal tern flying {Thalasseus maximus} USA.

Rob Tilley / Royal tern {Thalasseus maximus} Florida, USA.

Rob Tilley / Royal tern {Thalasseus maximus} Florida, USA.

Yva Momatiuk & John Eastcott / Royal Tern (Thalasseus maximus) on beach, spring, Gulf of Mexico, Padre Island National Seashore, Texas

Yva Momatiuk & John Eastcott / Royal Tern (Thalasseus maximus) wading in surf, spring, Gulf of Mexico, Padre Island National Seashore, Texas

Thomas Mangelsen / Royal Tern (Thalasseus maximus) nesting colony showing adults with eggs, Biloxi, Mississippi

Thomas Mangelsen / Royal Tern (Thalasseus maximus) nesting colony, Chandeleur Island, Louisiana

LYNN M. STONE / Royal tern, winter plumage {Thalasseus maximus} Florida, USA

Kevin Schafer / Royal Tern (Thalasseus maximus) calling, Los Haitises National Park, Dominican Republic

Steve Gettle / Royal Tern (Thalasseus maximus) flying, Fort Desoto Park, Florida

Pete Oxford / Royal Tern (Thalasseus maximus) flying, Bonaire, Netherlands Antilles, Caribbean

Barry Mansell / Royal tern with egg in nest hollow {Sterna maxima}

George McCarthy / Royal tern {Sterna maxima} Everglades Florida USA