Tui De Roy / Masked Booby (Sula dactylatra) courting pair on cliff nest, Wenman Island, Galapagos Islands, Ecuador

Christophe Courteau / Masked booby chick stretching wings {Sula dactylatra melanops} Galapapos.

Yukihiro Fukuda / Masked booby (Sula dactylatra) mating pair deciding where to lay their eggs, which they do directly on the ground, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) parent shading chick from harsh sunlight at nest, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) flying overhead, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) some flying over others on ground, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked boobies (Sula dactylatra), Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) head portrait, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) parent and young with beaks gaping to cool down in harsh sunlight, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked boobies (Sula dactylatra) on the ground, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) pair on beach, one calling, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) both parents take turns to brood eggs on ground nest, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) returning to brood solitary egg on ground nest, Christmas Island, Indian Ocean, July

Yukihiro Fukuda / Masked booby (Sula dactylatra) both parents take turns to brood solitary egg on ground nest, Christmas Island, Indian Ocean, July

Sue Flood / Masked Booby chick (Sula dactylatra) Ducie Island, Pitcairn Islands, South Pacific

Steve Gettle / Masked Booby (Sula dactylatra), Galapagos Islands, Ecuador

Steve Gettle / Masked Booby (Sula dactylatra) flying, Galapagos Islands, Ecuador

Brent Stephenson / Masked Booby (Sula dactylatra) chick in fluffy down on a coral-rubble beach. Ducie Island, Pitcairn Group, September.

Brent Stephenson / Immature Masked Booby (Sula dactylatra) in flight seen in profile. Takutea, Cook Islands, November.

Staffan Widstrand / Masked Booby (Sula dactylatra) preening its feathers. Punta Suarez, Espaniola, Galapagos, Ecuador, April.

Murray Cooper / Masked Booby (Sula dactylatra) and tourist, Ecuador

Sue Flood / Masked booby chick (Sula dactylatra) Ducie Island, Pitcairn Island Group, South Pacific. October

Sue Flood / Masked booby chick (Sula dactylatra) Ducie Island, Pitcairn Island Group, South Pacific. October

Sue Flood / Masked booby (Sula dacylatra) taking off, Henderson Island, Pitcairn Island, South Pacific. October

Sue Flood / Masked booby (Sula dactylatra) Henderson Island, Pitcairn Island, South Pacific. October

Gerrit Vyn / Masked Booby (Sula dactylatra) incubating at nest. Dry Tortugas National Park, Florida, USA

Hanne & Jens Eriksen / Masked booby {Sula dactylatra} adult in flight, Oman

Tom Vezo / Masked / Blue faced booby (Sula dactylatra) chick, Hood Island, Galapagos

JIM CLARE / Non-breeding Masked booby (Sula dactylatra melanops) molesting chick, Galapagos NP, Ecuador

Hanne & Jens Eriksen / Masked booby {Sula dactylatra} adult in flight over calm water, Dhofar, Oman

Juan Carlos Munoz / Masked booby {Sula dactylatra} Espanola Island, Galapagos, January

Juan Carlos Munoz / Masked booby {Sula dactylatra} Espanola Island, Galapagos, January

Juan Carlos Munoz / Masked booby {Sula dactylatra} Espanola Island, Galapagos, January

Juan Carlos Munoz / Masked booby {Sula dactylatra} preening, Espanola Island, Galapagos, January

Juan Carlos Munoz / Masked booby {Sula dactylatra} perched on coast, Espanola Island, Galapagos, January 2009

Juan Carlos Munoz / Looking down on Masked booby {Sula dactylatra} at nest with eggs on coast, Espanola Island, Galapagos, January 2009

Hanne & Jens Eriksen / Masked booby (Sula dactylatra melanops) adult and fledgling. Daymaniyat Islands, Oman.

Hanne & Jens Eriksen / Masked booby (Sula dactylatra melanops) fledgling. Daymaniyat Islands, Oman.

Hanne & Jens Eriksen / Masked booby (Sula dactylatra melanops) adult and fledgling. Daymaniyat Islands, Oman.

Hanne & Jens Eriksen / Masked booby (Sula dactylatra melanops) adult in flight. Daymaniyat Islands, Oman.

Hanne & Jens Eriksen / Masked booby (Sula dactylatra melanops) Daymaniyat Islands, Oman.

Pete Oxford / Two Nazca / Masked Boobies (Sula dactylatra granti) Punta Cevallos, Española / Hood Island, Galapagos Islands

Pete Oxford / Nazca / Masked Booby (Sula dactylatra granti) on rock, Punta Cevallos, Española / Hood Island, Galapagos Islands, Ecuador, South America

Pete Oxford / Nazca / Masked Booby (Sula dactylatra granti) on rocks, Punta Cevallos, Española / Hood Island, Galapagos Islands

Pete Oxford / Nazca / Masked Boobies (Sula dactylatra granti) courtship, Punta Cevallos, Española / Hood Island, Galapagos Islands

Pete Oxford / Nazca / Masked Booby (Sula dactylatra granti) with wings stretched, Punta Cevallos, Española / Hood Island, South America

Pete Oxford / Nazca / Masked Booby (Sula dactylatra granti) portrait, Wolf Island, Galapagos Islands, Ecuador, South America

Pete Oxford / Vampire / Sharp-beaked Ground Finch (Geospiza difficilis) feeding on blood from Nazca / Masked Booby (Sula dactylatra granti) Wolf Island, Galapagos Islands, Ecuador, South America

Pete Oxford / Vampire / Sharp-beaked Ground Finch (Geospiza difficilis) on a Nazca / Masked Booby (Sula dactylatra granti) where it feeds on blood, Wolf Island, Galapagos Islands, Ecuador, South America

Pete Oxford / Vampire / Sharp-beaked Ground Finch (Geospiza difficilis) feeding on blood from Nazca / Masked Booby (Sula dactylatra granti) Wolf Island, Galapagos Islands, Ecuador, South America

Tim Laman / Nazca Booby / masked booby (Sula dactylatra granti) mating pair, Espanola (Hood) Island, Galapagos Islands.

Tim Laman / Nazca booby / masked booby (Sula dactylatra granti) flying. Punta Vincente Roca, Isabela Island, Galapagos Islands.

Tim Laman / Nazca Booby / masked booby (Sula dactylatra granti) flying, Espanola (Hood) Island, Galapagos Islands.

Pete Oxford / Nazca booby / Masked booby flying {Sula dactylatra granti} Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca booby / Masked booby {Sula dactylatra granti} head portrait, Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca booby / Masked booby calling, beak open {Sula dactylatra granti} Tower / Genovesa Is, Galapagos.

Pete Oxford / Nazca booby / Masked booby preening {Sula dactylatra granti} Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca / Masked booby on nest {Sula dactylatra granti} Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca booby (formerly Masked booby) on nest with chick {Sula dactylatra granti} Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca / Masked booby {Sula dactylatra granti} Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca / Masked booby head portrait {Sula dactylatra granti} Tower / Genovesa Is, Galapagos

Pete Oxford / Nazca / Masked booby {Sula dactylatra granti} perching on stone looking backwards, Tower / Genovesa Island, Galapagos Islands.

Pete Oxford / Nazca booby (formerly Masked booby) (Sula granti) looking straight at camera, Española / Hood Island, Galapagos

Pete Oxford / Nazca booby (formerly Masked booby) (Sula dactylatra granti) Tower / Genovesa Island, Galapagos

Pete Oxford / Nazca booby (formerly Masked booby) (Sula granti) Española / Hood Island, Galapagos

Pete Oxford / Nazca booby (formerly Masked booby) (Sula dactylatra granti) Tower / Genovesa Island, Galapagos

Pete Oxford / Nazca boobies mating (formerly Masked booby) (Sula dactylatra granti) Tower / Genovesa Island, Galapagos

Pete Oxford / Masked Booby (Sula dactylatra) nesting colony observed by tourists from inflatable boat, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Masked Booby (Sula dactylatra) nesting colony observed by tourists from inflatable boat, Genovesa Island, Galapagos Islands, Ecuador

JIM CLARE / Hood mocking birds {Nesomimus trifasciatus macdonald} attacking Masked booby chick, Galapagos

Bernard Castelein / Nazca / Masked booby (Sula dactylatra granti) in flight, Galapagos, Ecuador

Bernard Castelein / Pair of Nazca / Masked booby (Sula dactylatra granti) courtship behaviour, Galapagos, Ecuador

Doug Perrine / Masked booby {Sula dactylatra melanops} Flinders reef, Coral Sea, Australia

Doug Perrine / Masked booby {Sula dactylatra melanops} Flinders reef, Coral Sea, Australia

Doug Perrine / Masked booby {Sula dactylatra melanops} pair exchange gift of coral in courtship display, Flinders reef, Coral Sea, Australia

Tom Vezo / Masked Booby {Sula dactylatra melanops} on nest with egg, Hood Island, Galapagos.

Bernard Castelein / Masked booby (Sula dactylatra granti) standing on rock, Genovesa, Galapagos, Ecuador, South America, endemic subspecies

Pete Oxford / Masked booby (Sula dactylatra melanops) adult with newly emerged chick, Isla de la Plata, Pacific Ecuador, endemic to area

Tom Vezo / Masked booby (Sula dactylatra melanops) pair mutual grooming, Tower Island, Galapagos, Ecuador

Tom Vezo / Masked booby (Sula dactylatra melanops) calling, Tower Island, Galapagos, Ecuador

JIM CLARE / Masked booby {Sula dactylatra melanops} attacked by Vampire finch, Galapagos NP, Ecuador

JIM CLARE / Vampire finch (Geospiza difficilis) attacking Masked booby, Wolf Island, Galapagos

Dave Watts / Masked Booby {Sula dactylatra melanops} female and large chick, Lord Howe Island, Australia

Todd Pusser / Masked booby {Sula dactylatra melanops} incubating eggs, Clipperton Island, Pacific

Todd Pusser / Masked booby {Sula dactylatra melanops} chick, Clipperton Island, Pacific.

Pete Oxford / Masked booby at sunset {Sula dactylatra melanops} Espanola/Hood Is, Galapagos Book page 125

Konrad Wothe / Masked Booby (Sula dactylatra) couple courting at sunset, Galapagos Islands, Ecuador

Tui De Roy / Masked Booby (Sula dactylatra) incubating egg on ground nest, Paradise Peninsula, Palmyra Atoll, US Line Islands, tropical Pacific

Tui De Roy / Masked Booby (Sula dactylatra) incubating egg on ground nest, Paradise Peninsula, Palmyra Atoll, US Line Islands, tropical Pacific

Flip Nicklin / Masked Booby (Sula dactylatra) couple at nest, Hawaiian Leeward Islands

Flip Nicklin / Masked Booby (Sula dactylatra) with two chicks, Hawaiian Leeward Islands

Tui De Roy / Masked Booby (Sula dactylatra) taking off from open ocean, Galapagos Islands, Ecuador

Tui De Roy / Masked Booby (Sula dactylatra) flying, coming to land on cliff edge, Wenman Island, Galapagos Islands, Ecuador

Tui De Roy / Masked Booby (Sula dactylatra) couple allopreening during courtship, Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Masked Booby (Sula dactylatra) couple allopreening during courtship, Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Sharp-beaked Ground-Finch (Geospiza difficilis) drawing blood from base of Masked Booby (Sula dactylatra) feathers, an adaptation unique to Wenman Island, Galapagos Islands, Ecuador