Flip de Nooyer / Black-browed Albatross (Thalassarche melanophrys) chicks on tower nests, South Georgia Island

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) 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

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

Fred Bavendam / Guineafowl Pufferfish (Arothron meleagris) in its golden color phase puffed up off of Tower Island, Galapagos Islands, Ecuador

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

Kevin Schafer / Red-footed Booby (Sula sula), Genovesa Island, Galapagos Islands, Ecuador

Oriol Alamany / Hiker Oriol Alamany in Punta Agnello with the medieval tower and lighthouse, Cap Corse, Haute-Corse, Corsica Island, France. Model released

Tui De Roy / Red-footed booby (Sula sula) nesting in mangrove thicket. Darwin Bay, Genovesa (Tower) Island, Galapagos, Ecuador, June.

Tui De Roy / Red-footed booby (Sula sula) incubating single egg with webbed feet. Darwin Bay, Genovesa (Tower) Island, Galapagos, Ecuador, June.

Tui De Roy / Red-footed booby (Sula sula) nesting in dry palo santo (Bursera graveolens). Prince Phillip's Steps, Genovesa (Tower) Island, Galapagos, June.

Tui De Roy / Red-footed booby (Sula sula) gathering nesting material. Darwin Bay, Genovesa (Tower) Island, Galapagos, Ecuador, June.

Sven Zacek / Small headland and watch-tower in lowland forested landscape. Hiiumaa Island, Estonia, Europe, April.

Bruno D'Amicis / Linosa, island of Sicily. View from the sea of the northern coast, with igneous rocks and ancient observation tower on the highest mountain. Italy, July.

Angelo Gandolfi / A medieval watch tower. Torre dello Zenobito. Capraia island, National Park of the Tuscany archipelago, Italy, May 2010

Wild Wonders of Europe / Lundgren / The "vigia" tower on Pico island, a look out for spotting whales, Azores, Portugal, June 2009

Wild Wonders of Europe / Lundgren / The lookout "vigia" in his white tower looking for whales, Pico island, Azores, Portugal, June 2009, model released

Merryn Thomas / Ruins of Signal tower (to warn of Napoleonic invasion) on the deserted island of Great Blasket. Blasket Islands, off the Dingle Peninsula, County Kerry, Republic of Ireland, May 2009.

Pete Oxford / Short eared owl {Asio flammeus} perched on rock, Tower Island, Galapagos

Tom Vezo / Red billed tropic bird {Phaethon aethereus} on cliff ledge, Tower Island, Galapagos

Oriol Alamany / Tasmanian Waratah bush (Telopea truncata) in bloom, below Weindorfers Tower, Cradle Mountain-Lake St. Clair National Park, Tasmania Island, Australia, December

Juan Carlos Munoz / Interior of Mousa Broch, ancient fortified stone tower, Mousa Island, Shetland Islands, Scotland, UK

Juan Carlos Munoz / Interior of Mousa Broch, ancient fortified stone tower, Mousa Island, Shetland Islands, Scotland, UK

Juan Carlos Munoz / Interior of Mousa Broch, ancient fortified stone tower, Mousa Island, Shetland Islands, Scotland, UK

Kevin Schafer / Large Cactus-Finch (Geospiza conirostris) on Opuntia (Opuntia sp) cactus flowers, Tower Island, Galapagos Islands, Ecuador

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

Tim Laman / Swallow-tailed gull (Larus furcatus) standing on {Opuntia sp} cactus calling, Genovesa (Tower) Island, Galapagos, June

Tim Laman / Short-eared owl (Asio flammeus galapagoensis)Genovesa / Tower Island, Galapagos, June

Jack Dykinga / Two swallow-tailed gulls (Creagrus fucatus) on their nest in a lava flow on Genovesa (Tower) Island, known as the "Island of Birds", Galapagos

Jack Dykinga / Two swallow-tailed gulls (Creagrus fucatus) at their nest in a lava flow on Genovesa (Tower) Island, known as the "Island of Birds", Galapagos

Peter Lewis / Sunset over Langstone Harbour from Hayling Bridge with The Spinniker Tower and Portsmouth in the background, Hampshire, UK

Pete Oxford / Candelabra Tree (Euphorbia candelabrum) youngling, Tower Island, Galapagos Islands, Ecuador

Pete Oxford / Red-footed Booby (Sula sula), Tower Island, Galapagos Islands, Ecuador

Pete Oxford / Lava Cactus (Brachycereus nesioticus) growing on the lava of Tower Island, Galapagos Islands, Ecuador

Pete Oxford / Lava Cactus (Brachycereus nesioticus) growing on the lava of Tower Island, Galapagos Islands, Ecuador

Pete Oxford / Nazca Booby (Sula granti) close up, Tower Island, Galapagos Islands, Ecuador

Pete Oxford / Red-footed Booby (Sula sula) portrait, Tower Island, Galapagos Islands, Ecuador

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

Pete Oxford / Lava cactus (Brachycereus nesioticus) growing on the lava of Tower Island, Galapagos Islands

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

Pete Oxford / Red footed booby (Sula sula websteri) white morph, Tower / Genovesa Island, Galapagos

Pete Oxford / Swallow-tailed gull (Larus / Creagrus furcatus) Genovesa / Tower Island, Galapagos

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

Pete Oxford / Red footed booby (Sula sula websteri) white morph, Tower / Genovesa Island, Galapagos

Pete Oxford / Red-footed booby (Sula sula websteri) Tower / Genovesa Island, Galapagos

Pete Oxford / Red footed booby (Sula sula websteri) white morph, on nest, Tower / Genovesa Island, Galapagos do.

Pete Oxford / Swallow-tailed gull (Larus / Creagrus furcatus) Genovesa / Tower Island, Galapagos

Pete Oxford / Swallow-tailed gull (Larus / Creagrus furcatus) amongst mangrove roots, Tower / Genovesa 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 / Galapagos Penguin (Spheniscus mendiculus) swimming, Isabela Island, Galapagos Islands, Ecuador

Pete Oxford / Nazca Booby (Sula granti) landing, Genovesa Island, Galapagos Islands, Ecuador

Tom Vezo / Boat moored offshore at Tower Island, Galapagos Islands, South America

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

Pete Oxford / Red-footed Booby (Sula sula) close up portrait, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Red-footed Booby (Sula sula) portrait amid mangroves, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Red-footed Booby (Sula sula) perching on roots beneath Opuntia (Opuntia sp) cactus, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Nazca Booby (Sula granti) pair courting, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Nazca Booby (Sula granti) pair courting, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Large Cactus-Finch (Geospiza conirostris) on Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Tourists walking on guided tour of Genovesa Island, Galapagos Islands, Ecuador

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

Pete Oxford / Red-footed Booby (Sula sula) affectionate couple, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Lava Heron (Butorides sundevalli) camouflaged on lava, Genovesa Island, Galapagos Islands, Ecuador

Pete Oxford / Red-footed Booby (Sula sula) pair sitting on nest in mangroves, Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / White-cheeked Pintail (Anas bahamensis) male in salt lagoon, Rabida Island, Galapagos Islands, Ecuador

Tui De Roy / Swallow-tailed Gull (Creagrus furcatus) world's only nocturnal and pelagic gull incubating egg on nest, Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / Swallow-tailed Gull (Creagrus furcatus) world's only nocturnal and pelagic gull departs at dusk to feed offshore, Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / Nazca Booby (Sula granti) pair at nest site, Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / Red-footed Booby (Sula sula) perching in Palo Santo Tree (Bursera graveolens) nest site, Genovesa Island, Galapagos Islands, Ecuador

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

Tui De Roy / Great Frigatebird (Fregata minor) female feeding juvenile long after fledging, Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) newly formed pair with male's pouch beginning to shrivel, Genovesa Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) male preening tail feathers, Genovesa Island, Galapagos Islands, Ecuador

Mark Moffett / Entomologist Dr. E. O. Wilson enjoying rainforest canopy view from 45 meter research tower, Barro Colorado Island, Panama

Mark Moffett / Entomologist Dr. E. O. Wilson searches for rainforest canopy ants with research assistant John Tobin in 45 meter tower, Barro Colorado Island, Panama

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

Pete Oxford / Cliff walls on Tower / Genoves Island, Galapagos Islands.

Pete Oxford / Darwin Bay landscape, Tower / Genovesa Island, Galapagos Islands.

Jose B. Ruiz / Tower and lighthouse, Tabaraca island, Alicante, Spain

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

Tui De Roy / Brown Pelican (Pelecanus occidentalis) breeding adult bathing, Darwin Bay, Genovesa Tower Island, Galapagos Islands, Ecuador

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

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

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

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

Tui De Roy / Swallow-tailed Gull (Creagrus furcatus) endemic, world's only nocturnal and pelagic gull departs to feed far offshore, Genovesa Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Great Frigatebird (Fregata minor) male in courtship display with extended gular pouch, Darwin Bay, Genovesa Tower Island, 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 / Nazca Booby (Sula granti) showing binocular vision, Genovesa Tower Island, Galapagos Islands, Ecuador