Juergen Freund / Split-level shot of mating pair of Green turtles (Chelonia mydas) in the reef shallows. Sipadan Island, Sabah, Malaysia, June

Juergen Freund / Split level shot of mating Green turtles (Chelonia mydas) in the reef shallows. Sipadan Island, Sabah, Malaysia, June

Peter Cairns / 2020VISION / Mute swan (Cygnus olor) pair on water in winter dawn mist, Loch Insh, Cairngorms NP, Highlands, Scotland UK, December. 2020VISION Book Plate.

Anup Shah / African lion (Panthera leo) male following a female, courtship, Masai Mara National Reserve, Kenya. February

Edwin Giesbers / Breeding pair of White Stork (Ciconia ciconia) on nest. The Netherlands, April.

Sergey Gorshkov / Kamchatka brown bear (Ursus arctos beringianus) mating, Kamchatka, Far east Russia, May

Fergus Gill / Grey seal (Halichoerus grypus) couple fighting as the male (right) tries to mate with the female. Scotland, October .

Daniel Heuclin / Pair of Rainbow Grasshoppers (Dactylotum bicolor) mating. Arizona, USA. Controlled conditions.

Solvin Zankl / Pair of Common european toads (Bufo bufo) swimming together in pond, Germany

Solvin Zankl / Pair of Common european toads (Bufo bufo) with strings of toadspawn, in pond, Germany. Specially commended in Wildlife Photographer of the Year (WPOY) 2013, Underwater Worlds Category.

Nick Garbutt / A pair of Toco Toucans (Ramphastos toco) flying across the Piquiri River at dawn, northern Pantanal, Mato Grosso, Brazil, September. (Digitally Modified)

David Tipling / European brown hare (Lepus europaeus) boxing in spring. Norfolk, UK, March

Laurent Geslin / Male Feral pigeon (Columba livia) touching female with his beak. Paris, France

Andrew Parkinson / Pair of Great Crested Grebes (Podiceps cristatus) during their elaborate courtship dance. March. Derbyshire, UK, March (non-ex)

Andrew Parkinson / Pair of Mallard ducks (Anas platyrhynchos) on a lake in dawn, Derbyshire, UK. April (non-ex)

Floris van Breugel / Burrowing Owls (Athene cunicularia) breeding pair standing near the entrance to their burrow, at sunset, Salton Sea, California, USA.

Vincent Grafhorst / African Lion (Panthera leo) pair mating, Khutse Game Reserve, Botswana

Nick Upton / Pair of Flesh Flies (Sarcophaga sp.) mating, Wiltshire pastureland, UK, May.

Roger Powell / Stone Curlew (Burhinus oedicnemus) pair walking through a flower meadow, Castro Verde, Portugal, April

Steve Knell / Harlequin ducks (Histrionicus histrionicus) male chasing female on riverbank, Iceland, May

Claudio Contreras / Pair of Northern elephant seals (Mirounga angustirostris) male holding female during copulation, Guadalupe Island Biosphere Reserve, off the coast of Baja California, Mexico, January

Dietmar Nill / European hare (Lepus europaeus) mating pair boxing in field, Slovakia

Dietmar Nill / European hare (Lepus europaeus) pair boxing in field, Slovakia

Russell Cooper / Mating pair of Small Blue Butterflies (Cupido minimus) on plant stem, Surrey, England, UK

LYNN M. STONE / Whooper Swan (Cygnus cygnus) breeding pair on water with cygnet; captive

Edwin Giesbers / Kittiwake (Rissa tridactyla) pair interacting, Farne Islands, Northumberland, UK, June

Staffan Widstrand / Arabian oryx (Oryx leucoryx) family, Dubai Desert Conservation Reserve, Dubai, UAE, Endangered species

Graham Eaton / Velvet swimming crab (Necora puber) pair mating, Trefor, Wales, UK, July.

Mary McDonald / Hyacinth Macaws (Anodorhynchus hyacinthinus) pair perched in Palm tree, the Pantanal, Brazil, South America.

Michael D. Kern / Zoo Atlanta / Lemur leaf frog (Hylomantis lemur) mating pair, captive, Critically endangered, from Central America

Michel Roggo / Marble trout (Salmo trutta marmorata) morph of the Brown Trout, male and female at spawning ground, Tolminka river, Slovenia, 2005

Michel Roggo / Sockeye / Red Salmon (Oncorhynchus nerka) pair spawning on gravel ground, Adams river, British Columbia, Canada, 1990

Michel Roggo / European Graylings (Thymallus thymallus) spawning, male in foreground, Lake of Thoune, Switzerland, 1992

Laurent Geslin / Mallard ducks (Anas platyrhynchos) male and female flying in Paris, France. March.

Nick Garbutt / Chin-strap Penguin (Pygoscelis antarcticus) displaying. Half-Moon Island, South Shetland Islands, Antarctica. February. (digitally stitched image)

Charlie Summers / King / Imperial Cormorants (Phalacrocorax albiventer) breeding pair display courtship behaviour in the form of a ritual dance at their nesting site on Saunders Island, Falkland Islands

Aflo / Black footed albatross (Phoebastria nigripes) pair displaying, Midway Islands, USA

Stephen Dalton / Common earwigs (Forficula auricularia) pair, male (left) and female (right), UK

David Kjaer / Pair of Northern pintail ducks (Anas acuta) in flight, Gloucestershire, England

Gary K. Smith / Red Deer stag and hind (Cervus elaphus) silhouetted at sunset, Holkham Park, Norfolk, UK, December

Dietmar Nill / Little owl (Athene noctua) pair perched, courtship behaviour, Spain

Anup Shah / Grey-crowned crane pair (Balearica regulorum) Masai Mara National Reserve, Kenya. December

Anup Shah / Grey-crowned cranes (Balearica regulorum)displaying. Masai Mara National Reserve, Kenya. December

Solvin Zankl / Male and female Long-tailed / Tisza mayfly (Palingania longicauda) mating, River Tisza, Hungary, Central Europe. June 2008

Wild Wonders of Europe / Hamblin / Red deer (Cervus elaphus) stags and hinds on the move, Oostvaardersplassen, Netherlands, June 2009

Gerrit Vyn / Adult Red-necked Grebes (Podiceps grisegena) in breeding plumage performing "whinny-braying" duet in defense of territory. Fairbanks, Alaska, USA, July.

Gerrit Vyn / A male Gunnison Sage Grouse (Centrocercus minimus) displaying near a female in snowy sage. Gunnsion County, Colorado, USA, April

Gerrit Vyn / Two pairs of Harlequin Ducks (Histrionicus histrionicus) in flight. Ocean County, New Jersey, USA, January.

Edwin Giesbers / Common european toad {Bufo bufo} two males attempting to mate with one female, the Netherlands

Edwin Giesbers / Common european toad {Bufo bufo} two males attempting to mate with one female, the Netherlands

Edwin Giesbers / Common european toad {Bufo bufo} pair in amplexus, the Netherlands

Wild Wonders of Europe / Munier / Reindeer (Rangifer tarandus) male sniffing at female in oestrus, Forollhogna National Park, Norway, September 2008

Wild Wonders of Europe / Widstra / Two White storks (Ciconia ciconia) one landing in tree, La Serena, Extremadura, Spain, March 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair before mating at nest site on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

George Sanker / African lion (Panthera leo) pair, Masai Mara National Reserve, Kenya, January

George Sanker / African lion (Panthera leo) male and female at sunrise, Masai Mara National Reserve, Kenya, January

Philippe Clement / European Brown bear (Ursus arctos) female climbed tree and is looking down at male bear, Bavarian Forest NP, Germany, Captive

Peter Cairns / Rock ptarmigan (Lagopus mutus) pair in winter plumage, Cairngorms NP, Grampian Mountains, Scotland, UK, February.

Wild Wonders of Europe / della Ferrera / White stork (Ciconia ciconia) pair on nest, Jasenovac village, Lonjsko Polje Nature Park, Sisack-Moslavina county, Slavonia region, Posavina area, Croatia, June 2009

Wild Wonders of Europe / Ziegler / Robber flies (Asilidae) mating, one with insect prey, The Peloponnese, Greece, May 2009

Laurie Campbell / Greater Scaup in flight (Aythya marila) two female and one male in flight over water, Lindisfarne NNR, Northumberland, England, December

Wild Wonders of Europe / Hermansen / Gannet (Morus bassanus) courtship, Saltee Islands, County Wexford, Republic of Ireland, June 2009

Wild Wonders of Europe / Hermansen / Gannets (Morus bassanus) pair, Saltee Islands, County Wexford, Republic of Ireland, June 2009

Wild Wonders of Europe / Hermansen / Gannet (Morus bassanus) courtship, Saltee Islands, County Wexford, Republic of Ireland, June 2009

Wild Wonders of Europe / Maitland / Mating pair of Azure damselflies (Coenagrion puella) on Plantain (Plantago sp) Lagadin region, Lake Ohrid, Galicica National Park, Macedonia, June 2009

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair courting on rocks on seabed, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Sá / Mediterranean Monk seal (Monachus monachus) pair mating, Deserta Grande, Desertas Islands, Madeira, Portugal, August 2009, Critically endangered species

Wild Wonders of Europe / Bartocha / Common red soldier beetle (Rhagonycha fulva) pair mating on Wild carrot (Daucus carota carota) flower, Hvblege, Mn, Denmark, July 2009

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

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) pair spawning, the dark one is the male, Lake Thun, Thun, Switzerland, March 2009

Wild Wonders of Europe / Zupanc / Alpine grasshopper (Miramella alpina) pair mating on a thistle, Triglav National Park, Slovenia, August 2009

Wild Wonders of Europe / Zupanc / Alpine grasshopper (Miramella alpina) pair mating on a thistle, Triglav National Park, Slovenia, August 2009. WWE OUTDOOR EXHIBITION.

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair displaying, silhouetted at nest on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair silhouetted at nest on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair at nest, dusk, with moon, Nemunas Delta, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) landing with nest material, silhouetted at dusk, Rusne, Nemunas Regional Park, Lithuania, June 2009 WWE OUTDOOR EXHIBITION. Wild Wonders kids book.

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair at nest on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) landing on chinmey with nesting material, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair at nest on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair, courtship, at nest on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair at nest site on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair at nest site with chick, Lithuania, May 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair silhouetted at nest on old chimney, Rusne, Nemunas Regional Park, Lithuania, June 2009

Wild Wonders of Europe / Hamblin / White stork (Ciconia ciconia) pair at nest engaged in courtship display, male with nesting material, Lithuania, May 2009

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) just after spawning, male in front, Lake of Thun, Thun, Switzerland, March 2009

Wild Wonders of Europe / Roggo / European grayling (Thymallus thymallus) pair spawning, male on the left, Lake of Thun, Thun, Switzerland, March 2009

Wild Wonders of Europe / Zupanc / Alpine grasshopper (Miramella alpina) pair mating on a thistle, Triglav National Park, Slovenia, August 2009

Wild Wonders of Europe / Zupanc / Alpine grasshopper (Miramella alpina) pair mating on a thistle, Triglav National Park, Slovenia, August 2009

Wild Wonders of Europe / Green / Northern gannets (Morus bassanus) pair at nest, Saltee Islands, Republic of Ireland, June 2009

Wild Wonders of Europe / Oxford / White stork (Ciconia ciconia) pair on nest, wetland reserve, Doana National & Natural Park, Huelva Province, Andalusia, Spain, May 2009

Wild Wonders of Europe / Green / Northern gannets (Morus bassanus) displaying, Saltee Islands, Republic of Ireland, May 2008

Andy Rouse / Osprey (Pandion haliaetus) pair mating on nest, UK, Europe

Ross Hoddinott / Blue-tailed damselfly {Ischnura elegans} mating pair, Cornwall, UK. June