Wild Wonders of Europe / Quinta / White Stork (Ciconia ciconia) pair at nest on coastal rock formation, Cabo Sardo (Cape) Alentejo, Natural Park of South West Alentejano and Costa Vicentina, Portugal, June 2009 WWE BOOK

Juan Carlos Munoz / Green winged macaw (Ara chloroptera) pair flying, Chapada dos Guimaraes, Mato Grosso, Brazil

Jouan & Rius / Puffin (Fratercula arctica) pair on sea cliffs, Shetland Islands, Scotland, UK

Carol Walker / Pair of King Penguins (Aptenodytes patagonicus) on Gold Beach, South Georgia Island, Sub Antarctica.

Hanne & Jens Eriksen / Kittiwake nesting colony {Rissa tridactyla} on cliffs, Bulbjerg, Denmark

Tom Vezo / Tufted puffin {Lunda cirrhata} pair perched on cliff edge, Alaska. Saint Paul Island

Konrad Wothe / Burchell's Zebra (Equus burchellii) pair resting, Serengeti National Park, Tanzania

Yva Momatiuk & John Eastcott / Grizzly Bear (Ursus arctos horribilis) pair of spring cubs, Denali National Park and Preserve, Alaska

Konrad Wothe / Red-crowned Crane (Grus japonensis) pair foraging in snow, Hokkaido, Japan

Yva Momatiuk & John Eastcott / Mustang (Equus caballus) pair of spring foals, Wyoming

Konrad Wothe / Red-crowned Crane (Grus japonensis) pair calling during courtship dance at their wintering grounds, Hokkaido, Japan

Tui De Roy / Waved Albatross (Phoebastria irrorata) pair bonding, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

Tui De Roy / Scarlet Macaw (Ara macao) pair perched on tree limb, originally hand raised by the research center, they are now living in the rainforest canopy, Tambopata-Candamo Reserve, Amazon Basin, Peru

Tui De Roy / Scarlet Macaw (Ara macao) pair 30 meters high in rainforest canopy, upper Tambopata River, Peruvian Amazon, Peru

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) pair sky pointing to keep cool in hot sun, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Scarlet Macaw (Ara macao) pair making a living in rainforest canopy, originally hand-raised by research center, Tambopata-Candamo Reserved Zone, Amazon Basin, Peru

Lynn M Stone / Bighorn sheep {Ovis canadensis} Female seeking refuge from male Jasper NP Alberta Canada

Wild Wonders of Europe / Widstrand / European bee eater (Merops apiaster) pair at nest hole , Danube delta rewilding area, Romania June

Winfried Wisniewski / Eland (Taurotragus oryx) pair, Masai Mara, Kenya

Tim Fitzharris / African Elephant (Loxodonta africana) pair smelling the air, Kenya

Fabrice Cahez / Black Storks (Ciconia nigra) mating at nest on cliff face. Extramadura, Spain, May.

Roger Powell / Greater black backed gull (Larus marinus) pair guarding their chicks at nest, Great Saltee Island, Wexford, Republic of Ireland, June

Roger Powell / Razorbill (Alca torda) pair courting at nest site, Great Saltee Island, Wexford, Republic of Ireland, June

Roger Powell / Razorbill (Alca torda) pair resting on a rocky ledge and panting in the sun, Great Saltee Island, Wexford, Republic of Ireland, June

Roger Powell / Razorbill (Alca torda) pair courting at nest site, Great Saltee Island, Wexford, Republic of Ireland, June

Roger Powell / Razorbill (Alca torda) pair courting at nest site, Great Saltee Island, Wexford, Republic of Ireland, June

Andy Rouse / Northern gannets (Morus bassanus) displaying at nest site, part of courtship, Bempton Cliffs, UK, July

Andy Rouse / Northern gannets (Morus bassanus) displaying at nest site, part of courtship, Bempton Cliffs, UK, July

Tui De Roy / White Rhinoceros (Ceratotherium simum) pair grazing, Solio Ranch, Kenya

Tui De Roy / Black Rhinoceros (Diceros bicornis) pair, Solio Ranch, Kenya

Ben Hall / Kittiwakes (Rissa tridactyla) pair on nest touching beaks, Farne Islands, Northumberland, UK June

Florian Möllers / Quinling Golden snub nosed monkey (Rhinopitecus roxellana qinlingensis), pair mating on cliff rocks, Zhouzhi Nature Reserve, Qinling Mountains, Shaanxi, China.

Gerrit Vyn / Glaucous winged gulls (Larus glaucescens) pair near their nest, St. Lazaria Island, Alaska, USA June

Peter Cairns / 2020VISION / Fulmar (Fulmarus glacialis) pair calling to each other, Shetland Isles, Scotland, UK, July

Steve Gettle / Ring-necked Duck (Aythya collaris) pair, Crow Island State Game Area, Michigan

Hanne & Jens Eriksen / Brunnich's guillemot / Thick billed murre (Uria lomvia) pair at nest, Iceland, June

Hanne & Jens Eriksen / Brunnich's guillemot / Thick billed murre (Uria lomvia) pair at nest, Iceland, June

Hanne & Jens Eriksen / Atlantic puffin (Fratercula arctica) pair in grass near nesthole, Iceland, June

Andrew Parkinson / Kittiwakes (Rissa tridactyla) breeding pair mating on their cliff top nest site, Farne Islands, Northumberland, UK, May.

Andrew Parkinson / Kittiwakes (Rissa tridactyla) pair greeting one another on their nest site, Saltee Islands, Republic of Ireland, UK, May.

Andrew Parkinson / Herring gulls (Larus argentatus) pair of adults, photographed through coastal flowers, perched on the cliff top, Bempton Cliffs RSPB Reserve, East Yorkshire, UK, May.

Ingo Arndt / Blue-eyed Cormorant (Phalacrocorax atriceps) pair flying, South Georgia Island

Fergus Gill / Northern gannet (Morus bassanus) pair having a dispute with the bird on the neighbouring nest. Troup Head, Scotland, August.

Tui De Roy / Reticulated Giraffe (Giraffa reticulata) pair, Ol Pejeta Conservancy, Kenya

Tui De Roy / Reticulated Giraffe (Giraffa reticulata) pair, Ol Pejeta Conservancy, Kenya

Fergus Gill / Herring gull (Larus argentatus) pair with a seacliff in the background. Fowlsheugh, Scotland, May .

Pete Oxford / Flightless Cormorant (Phalacrocorax harrisi) pair, Fernandina Island, Galapagos Islands, Ecuador

Juan Carlos Munoz / Two nesting pairs of Red-legged cormorants (Phalacrocorax gaimadi). Puerto Deseado, Patagonia, Argentina, Nov 2008

Juan Carlos Munoz / Pair of Red-legged cormorants (Phalacrocorax gaimardi) on their nest on a rock ledge. Puerto Deseado, Patagonia, Argentina, Nov 2008

Juan Carlos Munoz / Pair of Red-legged cormorants (Phalacrocorax gaimardi) nesting on a rock ledge. Puerto Deseado, Patagonia, Argentina, Nov 2008

Philippe Clement / Pair of Razorbills (Alca torda) nesting in cliff face at the Fowlsheugh RSPB reserve, Scotland, UK

Steven Kazlowski / Pair of Atlantic puffins (Fratercula arctica) perched on cliffs along coast of Svalbard in summertime, Arctic.

Hanne & Jens Eriksen / Kittiwake {Rissa tridactyla} pair on nest, bonding, Iceland, June

Peter Bassett / Wandering Albatross pair (Diomedea exulans) at nest site in tussock grass, Bird Island, South Georgia

Dave Watts / Northern bald / Hermit ibis / Waldrapp (Geronticus eremita) pair, Critically endangered, captive

Dave Bevan / Chough (Pyrrhocorax pyrrhocorax) pair with fledgeling on cliff ledge, Wales, UK

David Tipling / Sand Martins {Riparia riparia} at nesting colony in cliff, North Norfolk, UK, July

Mark Bowler / Red-legged cormorant / Chuita {Phalacrocorax gaimardi} perched on narrow cliff ledge, Paracas National reserve, Peru

Tui De Roy / Emperor Penguin (Aptenodytes forsteri) pair, Antarctica

Wild Wonders of Europe / Liodden / Kittiwake (Rissa tridactyla) pair at nest on cliff, Kongsfjorden, Spitsbergen, Svalbard, Norway, June 2009

Anup Shah / Gelada baboon (Theropithecus gelada) female grooming male on cliff edge, Simien Mountains National Park, Ethiopia, November

Anup Shah / Gelada baboon (Theropithecus gelada) male grooming a female on cliff edge, Simien Mountains National Park, Ethiopia, November

Jose B. Ruiz / Bonelli's eagle {Hieraaetus fasciatus} female at nest with chick, male returning to nest, Spain

Michael Quinton / Trumpeter Swan (Cygnus buccinator) pair swimming, Alaska

Alan Williams / Common raven (Corvus corax) pair flying in formation, South Stack, Anglesey, Wales, UK, September

Alan Williams / Chough (Pyrrhocorax pyrrhocorax) pair on sea cliffs, South Stack, Anglesey, UK, September

Wild Wonders of Europe / Unterthiner / Eleonora's falcon (Falco eleonorae) pair on rock ledge, Andros, Greece, September 2008

Gabriel Rojo / Red-legged cormorant (Phalacrocorax gaimardi) pair at nest site, Ria de Puerto Deseado Nature Reserve, Santa Cruz Province, Patagonia, Argentina, December

Gabriel Rojo / Red-legged cormorant (Phalacrocorax gaimardi) pair at nest sit on rock face, Ria de Puerto Deseado Nature Reserve, Santa Cruz Province, Patagonia, Argentina, December

Wild Wonders of Europe / Unterthiner / Eleonora's falcon (Falco eleonorae) pair with prey, Andros, Greece, September 2008

Wild Wonders of Europe / Unterthiner / Pair of Eleonora's falcons (Falco eleonorae) on cliff, Andros, Greece, September 2008

Andrew Walmsley / Spotted shag (Phalacrocorax punctatus) pair perched on cliff face, Bank's Peninsula, South Island, New Zealand, October

Sebastian Kennerknecht / Tundra Swan (Cygnus columbianus) pair landing, Tule Lake National Wildlife Refuge, California

Juan Carlos Munoz / Green winged macaw (Ara chloroptera) pair flying, Chapada dos Guimaraes, Mato Grosso, Brazil

Juan Carlos Munoz / Green winged macaw (Ara chloroptera) pair flying, Chapada dos Guimaraes, Mato Grosso, Brazil

Luis Quinta / Two White storks {Ciconia ciconia} courtship on nest, Cape Sardio, Costa Vicentina, Alentejo, Portugal

Luis Quinta / White stork {Ciconia ciconia} pair on nest in distance on exposed rock on coast, Costa Vicentina, Alentejo, Portugal

Kevin Schafer / Red Howler Monkey (Alouatta seniculus) pair in canopy, Rio Negro, Amazon, Brazil

Andrew Parkinson / Kittiwake {Rissa tridactyla} mating pair, interacting during mating, Farne Islands, Northumberland, UK

Andrew Parkinson / Kittiwake {Rissa tridactyla} adults greeting each other after one returns to the nest site, Farne Islands, Northumberland, UK

Winfried Wisniewski / Great White Pelican (Pelecanus onocrotalus) pair displaying, Lake Nakuru National Park, Kenya

Roger Powell / Griffon Vulture {Gyps fulvus} pair flying in parellel courtship flight in front of breeding cliff, Garganta Verde, Sierra de Grazalema, Andalusia, Spain

Roger Powell / Griffon Vulture {Gyps fulvus} pair flying in parellel courtship flight in front of breeding cliff, Garganta Verde, Sierra de Grazalema, Andalusia, Spain

Dave Bevan / Kittiwake (Rissa tridactyla) pair feeding chicks at nest on cliff ledge, Farne Is, UK, June

Dave Bevan / Shag (Phalacrocorax aristotelis) pair at nest on rocks, Farne Is, UK, June

Dietmar Nill / Sand Martin (Riparia riparia) pair at nesting burrow, Bulgaria

Ingo Arndt / Soaptree Yucca (Yucca elata) pair in gypsum sand, White Sands National Park, Chihuahua Desert, New Mexico

Steve Knell / Kittiwake (Rissa tridactyla) pair interacting at breeding colony. Northumberland, July

Jose B. Ruiz / European bee eater {Merops apiaster} flying to nest with prey. Alicante, Spain

Suzi Eszterhas / Burchell's Zebra (Equus burchellii) pair drinking at waterhole, Ngorongoro Conservation Area, Tanzania, east Africa

Konrad Wothe / Cowboys and a cowgirl riding Domestic Horse (Equus caballus) pair beside pond, Oregon

Mark Raycroft / Rhodesian Ridgeback (Canis familiaris) pair of puppies showing signature ridge in their fur

Tui De Roy / Waved Albatross (Phoebastria irrorata) pair bonding, Punta Cevallos, Espanola Island, Galapagos Islands, Ecuador

Richard Du Toit / Klipspringer antelope {Oreotragus oreotragus} pair on rocks, Savute Chobe NP, Botswana

Niall Benvie / Fulmars {Fulmarus glacialis} nesting on red sandstone cliffs, Red Head, Angus, Scotland

Staffan Widstrand / Kittiwake pair nesting on narrow cliff ledge {Rissa tridactyla} Talan Island, Sea of Okhotsk, Siberia, Russia