John Chan / Juvenile Yellow-crowned night heron (Nyctanassa violacea)predating a twig, learning stalking and hunting skills, Southern California, USA, July.

Tui De Roy / Yellow-crowned night heron (Nyctanassa / Nyctanassa violacea) portrait. Galapagos Islands, Ecuador, June.

Tim Laman / Yellow-crowned Night Heron (Nyctanassa violacea) standing on lava rock. Santiago Island, Galapagos

Shane P. White / Yellow-crowned Night Heron (Nyctanassa violacea) in defensive posture, Castara Beach, Trinidad and Tobago, Caribbean

Shane P. White / Yellow-crowned Night Heron (Nyctanassa violacea) in defensive posture, Castara Beach, Trinidad and Tobago, Caribbean

John Chan / Juvenile Yellow-crowned night heron (Nyctanassa violacea) catching a Striped shore crab (Pachygrapsus crassipes), Southern California, USA, July.

John Chan / Juvenile Yellow-crowned night heron (Nyctanassa violacea) catching a Striped shore crab (Pachygrapsus crassipes), Southern California, USA, July.

Lynn M. Stone / Dunes and vegetative cover along Tampa Bay with tracks of Yellow-crowned night heron (Nyctanassa violacea) a predator of Ghost Crabs (Ocypodinae) that live in dune burrows), Muillet Key, St. Petersbur...

Tui De Roy / Yellow-crowned night herons (Nyctanasa violacea) adult and juvenile, Puerto Egas, Santiago Island, Galapagos

Tui De Roy / Yellow-crowned Night Heron (Nyctanassa violacea) parent with chicks in nest, Academy Bay, Santa Cruz Island, Galapagos Islands, Ecuador

Tui De Roy / Yellow-crowned Night Heron (Nyctanassa violacea) parent with chicks in nest, Academy Bay, Santa Cruz Island, Galapagos Islands, Ecuador

Roy Mangersnes / Yellow-crowned night-heron (Nyctanassa violacea) portrait on Genovesa, Galapagos.

Roy Mangersnes / Yellow-crowned night-heron (Nyctanassa violacea) portrait on Genovesa, Galapagos.

Lynn M. Stone / Yellow-crowned night heron (Nyctanassa violacea) stalking ghost crabs on sand dune. Mullet Key, Tampa Bay, St, Petersburg, Florida, USA.

Robin Chittenden / Yellow-crowned night heron (Nyctanassa violacea) Trinidad and Tobago, April

Nate Chappell/ BIA / Yellow-crowned Night Heron (Nyctanassa violacea) swallowing frog, Texas

George Sanker / Yellow crowned Night Heron (Nyctanassa violacea) with prey in beak, Tampa Bay, Florida, USA.

Melvin Grey / Yellow-crowned night heron (Nyctanassa violacea cayennensis) Speyside, Tobago.

George Sanker / Yellow-crowned night heron (Nyctanassa violacea) in mangrove swamp. Ding Darling National Wildlife Refuge, Florida, USA, March.

John Cancalosi / Yellow-crowned night heron (Nyctanassa violacea, formerly placed in the genus Nycticorax), Washington DC, USA, May.

John Cancalosi / Yellow-crowned night heron (Nyctanassa violacea, formerly placed in the genus Nycticorax), Washington DC, USA, May.

Pete Oxford / Yellow-crowned night heron (Nyctanassa violacea) two on beach, Galapagos.

Ole Jorgen Liodden / Yellow-crowned night heron (Nyctanassa violacea pauper) catching Ghost crab (Ocypode) on beach, Galapagos.

LYNN M. STONE / Yellow-crowned night heron (Nyctanassa violacea) with Ghost Crab on beach dune along Tampa Bay, Gulf of Mexico, St. Petersburg, Florida, USA

Will Burrard-Lucas / Yellow-crowned night heron (Nyctanassa violacea) eating a crab, Little Cayman Island, Cayman Islands.

Alan Murphy / Yellow-crowned Night Heron (Nyctanassa violacea), Texas

Denis-Huot / Yellow-crowned Night-Heron (Nyctanassa violacea) Tortugueros, Costa Rica

Christophe Courteau / Yellow crowned night heron in cave {Nyctanassa violacea} Santiago Is, Galapagos.

Tui De Roy / Yellow-crowned night heron (Nyctanassa / Nyctanassa violacea) juvenile. Galapagos Islands, Ecuador, December.

LYNN M. STONE / Yellow-Crowned Night Heron (Nyctanassa / Nyctanassa violacea) sub-adult with caught ghost crab on beach dune. Tampa Bay, Florida, USA, November.

LYNN M. STONE / Yellow-Crowned Night Heron (Nyctanassa / Nyctanassa violacea) adult in non-breeding plumage foraging at low tide. Tarpon Springs, Florida, USA, November.

Gerrit Vyn / Yellow-crowned Night-Heron (Nyctanassa violacea) with fiddler crab prey. Plaquemines Parish, Louisiana, USA, July.

Gerrit Vyn / Yellow-crowned Night-Heron (Nyctanassa violacea) head portrait, Plaquemines Parish, Louisiana, USA. July.

Tim Laman / Yellow-crowned night heron (Nyctanassa violacea) Sanibel Island, Florida, USA.

George Sanker / Yellow crowned night heron (Nyctanassa violacea) feeding, Tampa Bay, Florida, Winter

Claudio Contreras / Yellow-crowned night heron (Nyctanassa violacea) beside water, Puerto Vallarta, Pacific Ocean, Mexico, November

Rob Tilley / Yellow-Crowned Night Heron (Nyctanassa violacea) foraging on seashore, Sanibel Island, Florida, USA

Rob Tilley / Yellow-Crowned Night Heron (Nyctanassa violacea) Sanibel Island, Florida, USA

Rob Tilley / Yellow-Crowned Night Heron (Nyctanassa violacea) Sanibel Island, Florida, USA

Rob Tilley / Yellow-Crowned Night Heron (Nyctanassa violacea) walking along seashore, Sanibel Island, Florida, USA

Adrian Davies / Yellow-crowned night heron (Nyctanassa violacea), Sanibel Island, Florida, USA.

Kevin Schafer / Yellow-crowned Night-Heron (Nyctanassa violacea), Galapagos Islands, Ecuador

Thomas Marent / Yellow-crowned Night-Heron (Nyctanassa violacea) perched on branch, Cahuita National Park, Costa Rica

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea) standing on one leg, Florida

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea) walking through wetland plants, Florida

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea) standing in grass, Florida

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea) standing in the water, Florida

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea), Florida

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea), Florida

Winfried Wisniewski / Yellow-crowned Night-Heron (Nyctanassa violacea) eating a crab, Florida

Tim Laman / Immature yellow-crowned night heron (Nyctanassa violacea) Genovesa / Tower Island, Galapagos, June

Tim Laman / Immature yellow-crowned night heron (Nyctanassa violacea) sunning, Genovesa / Tower Island, Galapagos, June

Nick Garbutt / Yellow-crowned Night Heron (Nyctanassa violacea) amongst lava on shore line. Isla Floreana, Galapagos Islands.

Nick Garbutt / Yellow-crowned Night Heron (Nyctanassa violacea) preying on turtle hatchling amongst lava on shore line. Isla Floreana, Galapagos Islands.

Patrick Morris / Yellow crowned night heron {Nyctanassa violacea} Espanola Is, Galapagos

Pete Oxford / Yellow-crowned Night-Heron (Nyctanassa violacea) juvenile, Tower Island, Galapagos Islands, Ecuador

Rolf Nussbaumer / Yellow-crowned Night-Heron {Nycticorax / Nyctanassa violacea} adult preening, Rio Grande Valley, Texas, USA

Pete Oxford / Juvenile Yellow-crowned night heron (Nyctanassa violacea), Tower / Genovesa Island, Galapagos Islands, South America

Tom Vezo / Yellow crowned night heron {Nyctanassa violacea} walking, Florida, USA

Tom Vezo / Yellow crowned night heron {Nyctanassa violacea} feeding, Florida, USA

Tom Vezo / Yellow crowned night heron {Nyctanassa violacea} perching on fence, Texas, USA

Steven David Miller / Yellow crowned night heron {Nyctanassa violacea} Mangrove Is, Florida, USA

George McCarthy / Yellow crowned night heron {Nyctanassa violacea} Everglades NP, Florida, USA

Bernard Castelein / Yellow-crowned night heron collecting nesting material {Nyctanassa violacea} Sanibel Is, Florida

Pete Oxford / Yellow crowned night heron, juvenile {Nyctanassa violacea} Machalilla NP. Ecuador

Barry Mansell / Yellow crowned night heron with chicks at nest {Nyctanassa violacea} Florida, USA.

Pete Oxford / Yellow-crowned Night-Heron (Nyctanassa violacea) perched in tree, Machalilla National Park, Ecuador

Tom Vezo / Yellow-crowned Night-Heron (Nyctanassa violacea) calling from perch, Texas

Tom Vezo / Yellow-crowned Night-Heron (Nyctanassa violacea) wading among Mangrove roots, Florida

Jim Brandenburg / Yellow-crowned Night-Heron (Nyctanassa violacea), Florida

Steven David Miller / Yellow crowned night heron {Nyctanassa violacea} Sanibel Is, Florida, US Ding darling

Pete Oxford / Juvenile yellow crowned night heron {Nyctanassa violacea} sunbathing, Tower/Genovesa Is, Galapagos

Tom Vezo / Yellow crowned night heron, Florida, USA

George McCarthy / Yellow crowned night heron, Everglades, Florida, USA

George McCarthy / Yellow crowned night heron juvenile, Everglades, Florida, USA

George McCarthy / Yellow crowned night heron, Everglades, Florida, USA

George McCarthy / Yellow crowned night heron, Everglades, Florida, USA

George McCarthy / Yellow crowned night heron, Everglades, Florida, USA

George McCarthy / Yellow crowned night heron, Everglades, Florida, USA

George McCarthy / Yellow crowned night heron (Nyctanassa violacea). Florida Everglades, USA

George McCarthy / Yellow crowned night heron adult in breeding plumage, Everglades, Florida, USA

Tui De Roy / Yellow-crowned Night Heron (Nyctanassa violacea), Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / Yellow-crowned Night Heron (Nyctanassa violacea) and Sally Lightfoot Crab (Grapsus grapsus), Puerto Egas, Santiago Island, Galapagos Islands, Ecuador

Konrad Wothe / Yellow-crowned Night Heron (Nycticorax violaceus) flying, Tobago, West Indies, Caribbean

Steve Gettle / Yellow-crowned Night Heron (Nyctanassa violacea), J. N. Ding Darling National Wildlife Refuge, Florida

Robin Chittenden / Yellow-crowned night heron (Nyctanassa violacea) portrait, Costa Rica, March

Steven David Miller / Yellow crowned night heron chick in nest. Florida, USA. {Nyctanassa violacea}

Tui De Roy / Male Yellow-crowned night-heron (Nyctanassa violacea) in breeding plumage with subdued colours of Galapagos subspecies, perched on rocks. Galapagos Islands, Ecuador.

Tui De Roy / Male Yellow-crowned night-heron (Nyctanassa violacea), in breeding plumage with subdued colours of Galapagos subspecies, performing courtship display for female. Galapagos Islands, Ecuador.

Tui De Roy / Pair of Yellow-crowned night-herons (Nyctanassa violacea), in breeding plumage with subdued colours of Galapagos subspecies, perched on rocks. Galapagos Islands, Ecuador.

Roland Seitre / Yellow-crowned night heron (Nyctanassa violacea) foraging in shallow water, St Martin, Caribbean.

John Shaw / Yellow-crowned night heron (Nyctanassa violacea) in breeding plumage. St. Johns Management Area, Florida, USA. April.

Sylvain Cordier / Yellow-crowned night heron (Nyctanassa violacea) perched in tree. Puerto San Carlos, Baja California Sur, Mexico.

Claudio Contreras / Yellow-crowned Night-heron (Nyctanassa violacea), Ria Celestun Biosphere Reserve, Yucatan Peninsula, Mexico, January

Claudio Contreras / Yellow-crowned Night-heron (Nyctanassa violacea) juvenile, Ria Celestun Biosphere Reserve, Yucatan Peninsula, Mexico, January