John Shaw / Great frigatebird (Fregata minor) male at nest site, with gular sac inflated to attract females. Genovesa Island, Galapagos, May.

David Pattyn / Magnificent Frigatebirds (Fregata magnificens) trying to steal fish from a fisherman coming on land with a fresh catch, Puerto Lopez , Santa Elena Peninsula, Manabi Province, Ecuador, July

David Pattyn / Magnificent Frigatebirds (Fregata magnificens) trying to steal fish from fishermen coming on land with a fresh catch, Puerto Lopez , Santa Elena Peninsula, Manabi Province, Ecuador, July

David Pattyn / Magnificent Frigatebirds (Fregata magnificens) trying to steal fish from fishermen coming on land with a fresh catch, Puerto Lopez , Santa Elena Peninsula, Manabi Province, Ecuador, July

Claudio Contreras / Great Frigatebird (Fregata minor) departing from nest, San Benedicto Island, Revillagigedo Archipelago Biosphere Reserve / Archipielago de Revillagigedo UNESCO Natural World Heritage Site (Socorro Isl...

Andy Rouse / Magnificent frigate bird (Fregata magnificens) group flying against cloudy sky, Galapagos.

Ole Jorgen Liodden / Magnificent frigatebird (Fregata magnificens) male with gular pouch, Galapagos.

Ole Jorgen Liodden / Magnificent frigatebird (Fregata magnificens) in Galapagos

Tui De Roy / Great frigatebird (Fregata minor) male displaying inflated gular sac, Galapagos, Ecuador.

Tui De Roy / Great frigatebird (Fregata minor) male guarding single chick. Punta Cevallos, Espanola Island, Galapagos, Ecuador, May.

Cheryl-Samantha Owen / Great frigate birds (Fregata minor) sitting in tree, Aldabra Atoll, Seychelles, Indian Ocean

Tui De Roy / Magnificent frigatebirds (Fregata magnificens) in low flight ovehead. Espanola Island, Galapagos, Ecuador, December.

Tui De Roy / Great frigatebird (Fregata minor) male taking flight at dusk. Espanola Island, Galapagos, Ecuador, May.

Ole Jorgen Liodden / Magnificent Frigatebird (Fregata magnificens) male displaying, red throat pouch inflated. Galapagos

Ole Jorgen Liodden / Magnificent Frigatebird (Fregata magnificens)displaying in flight, red pouch inflated. Galapagos

Charlie Summers / Christmas Island Frigatebird (Fregata andrewsi) hovering in flight. Christmas Island, Indian Ocean, Australia, December.

Kevin Schafer / Ascension frigatebird (Fregata aquila) male soaring high, Ascension island, Atlantic Ocean, Vulnerable species

Kevin Schafer / Ascension frigatebird (Fregata aquila) flock soaring high, Ascension island, Atlantic Ocean, Vulnerable species

Ingo Arndt / Christmas Island Frigatebird (Fregata andrewsi) in flight, This bird is critically endangered, and endemic to Christmas Island. Christmas Island, Indian Ocean, Australian Territory. November.

Ingo Arndt / Great frigatebird (Fregata minor listeri) drinking freshwater on the wing, Christmas Island, Indian Ocean, Australian Territory, November

Gerrit Vyn / Adult male Magnificent Frigatebird (Fregata magnificens) displaying. Dry Tortugas NP, Florida, USA

Patrick Morris / Magnificent frigate bird {Frigata magnificens} pair on nest, male displaying with red throat pouch inflated, Genovesa Is, Galapagos

Pete Oxford / Great frigatebird (Fregata minor) male displaying, pouch inflated, Galapagos

Pete Oxford / Great frigate bird (Fregata minor) female on nest with chick, Galapagos

Pete Oxford / Great frigate bird feeding chick {Fregata minor} Genovesa, Galapagos.

Pete Oxford / Great frigate bird (Fregeta minor) male with pouch fully inflated. Orgenoves Island, Galapagos

Pete Oxford / Great Frigate bird (Fregeta minor) male courtship display. Galapagos, Tower Orgenoves Island

Tui De Roy / Great Frigatebird (Fregata minor) parent and chick on nest, Genovesa Island, Galapagos Islands, Ecuador

Tim Fitzharris / Atlantic Sailfish (Istiophorus albicans) and Magnificent Frigatebird (Fregata magnificens) flock hunting Round Sardinella (Sardinella aurita) school, Isla Mujeres, Mexico

Tui De Roy / Great Frigatebird (Fregata minor) female guarding chick, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) courting males vying for female's attention, Genovesa Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) recently formed pair, female inspecting male in courtship display with extended gular pouch, Genovesa Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) recently formed pair, female inspecting male in courtship display with extended gular pouch, Genovesa Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) male with inflated gular pouch in courtship display, Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) pair courting, male in full display with inflated gular air pouch, Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) male in courtship display with fully inflated gular air pouch, Tower Island, Galapagos Islands, Ecuador

Doc White / Magnificent frigatebird (Fregata magnificens) colony nesting in mangroves, Magdalena Bay, Baja California, Mexico.

Roland Seitre / Magnificent frigate birds (Fregata magnificens) gathering to roost at dusk, Barbuda, Caribbean Sea.

Roland Seitre / Magnificent frigate bird (Fregata magnificens) perched on branch with wings spread, Barbuda, Caribbean Sea.

Roland Seitre / Magnificent frigate bird (Fregata magnificens) flying high against a blue sky and moon, Barbuda, Caribbean Sea.

Roland Seitre / Pair of Magnificent frigate birds (Fregata magnificens) at nest site, male with gular sac inflated to attract females, Barbuda, Caribbean Sea.

Roland Seitre / Male Magnificent frigate bird (Fregata magnificens) in flight with gular sac inflated, Barbuda, Caribbean Sea.

Roland Seitre / Male Magnificent frigate bird (Fregata magnificens) in flight with gular sac inflated, Barbuda, Caribbean Sea.

Roland Seitre / Male Magnificent frigate bird (Fregata magnificens) in flight with gular sac inflated, Barbuda, Caribbean Sea.

Roland Seitre / Male Magnificent frigate bird (Fregata magnificens) in flight with gular sac inflated, Barbuda, Caribbean Sea.

Roland Seitre / Male Magnificent frigate bird (Fregata magnificens) in flight with gular sac inflated, Barbuda, Caribbean Sea.

Bruce Thomson / Male Great frigatebird (Fregata minor) in breeding condition with semi-inflated throat pouch, Christmas Island, Australia.

Bruce Thomson / Male Great frigatebird (Fregata minor) in breeding condition with semi-inflated throat pouch, Christmas Island, Australia.