JIM CLARE / Buffon's / Great green macaw (Ara ambigua) adult pair at nest hole in Almendro tree, Costa Rica

JIM CLARE / Buffon's / Great green macaw (Ara ambigua) adult pair in nest hole in Almendro tree, Costa Rica

Jeff Vanuga / Gentoo Penguin (Pygoscelis papua) mating. Cuverville Island, Antarctica.

Denis-Huot / Masai Giraffe (Giraffa camelopardalis tippelskirchi) male and female (back). Masai-Mara Game Reserve, Kenya.

David Pattyn / Black necked grebe (Podiceps nigricollis) frontal view of pair mating, La Dombes lake area, France, April

Linda Pitkin / 2020VISION / Spiny spider crab (Maja brachydactyla / squinado) pair on rock covered with red algae, Lundy Island Marine Conservation Zone, Devon, England, UK, May.

Michel Roggo / Sockeye / Red Salmon (Oncorhynchus nerka) on spawning migration; males surrounding a female. Adams River, British Columbia, Canada, October.

Anup Shah / Western chimpanzee (Pan troglodytes verus) female 'Fanle' aged 13 years and protecting her infant son 'Flanle' aged 3 years from an aggressive male, Bossou Forest, Mont Nimba, Guinea. January 2011.

Anup Shah / Western chimpanzee (Pan troglodytes verus) female 'Fana' aged 54 years playing with her infant grandson 'Flanle' aged 3 years, Bossou Forest, Mont Nimba, Guinea. January 2011.

Fiona Rogers / Western chimpazee (Pan troglodytes verus) female 'Fanle' aged 13 years with suckling infant male 'Flanle' aged 3 years, Bossou Forest, Mont Nimba, Guinea. January 2011.

Markus Varesvuo / Two Sparrowhawks (Accipiter nisus) immature male and female in flight, male on left, Falsterbo, Sweden. September.

Christophe Courteau / Pair of West African giraffes {Giraffe camelopardis peralta}. Male on right, female on left.

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years feeding on sedge grasses while juvenile male 'Mobangi' aged 5 years feeds on rotten wood in the background, Bai...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years feeding on rotten wood from a tree while female 'Malui' and their juvenile son 'Tembo' aged 4 years s...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years feeding on rotten wood from a tree while female 'Malui' and their juvenile son 'Tembo' aged 4 years s...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years drinking from a river while sub-adult female 'Mosoko' aged 8 years crosses bi-pedally, Bai Hokou, Dza...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years drinking from a river watched by sub-adult female 'Mosoko' aged 8 years and juvenile male 'Mobangi' a...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years approaching a river while sub-adult female 'Mosoko' aged 8 years and juvenile male 'Mobangi' aged 5 y...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) juvenile male 'Mobangi' aged 5 years playing with sub-adult female 'Mosoko' aged 8 years with juvenile male 'Tembo' aged 4 years watching in the backg...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years and juvenile male 'Mobangi' aged 5 years drinking from a dirty pool of water in Bai Hokou, Dzanga Sangha Specia...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years following juvenile male 'Mobangi' aged 5 years for his food, Bai Hokou, Dzanga Sangha Special Dense Forest Rese...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years playing with juvenile male 'Mobangi' aged 5 years, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Centr...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years and juvenile male 'Mobangi' aged 5 years approaching with curiosity, Bai Hokou, Dzanga Sangha Special Dense For...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) sub-adult female 'Mosoko' aged 8 years and juvenile male 'Mobangi' aged 5 years drinking from a dirty pool of water in Bai Hokou, Dzanga Sangha Specia...

Andy Sands / Small emperor moth (Saturnia pavonia) male (bottom) and female with wings open showing eyespots on lichen covered twig, Captive, UK, April

Andy Sands / Small emperor moth (Saturnia pavonia) male below female both displaying eyespots on Gorse, Captive, UK, April

Steven Kazlowski / Killer WHale / Orca (Orcinus orca) bull and cow in Resurrection Bay, Kenai Fjords National Park, outside Seward, Alaska, May.

Yukihiro Fukuda / Two male Japanese giant salamanders (Andrias japonicus) fertilizing the eggs of a female, Japan, September

Cheryl-Samantha Owen / Green turtles (Chelonia mydas) pair mating near surface, Aldabra Atoll, Seychelles, Indian Ocean

Solvin Zankl / Common European toads (Bufo bufo) mating, with membranes closed over eyes for protection, Solling, Central Germany.

Roger Powell / Pair of European Bee-eater (Merops apiaster) on a bank above their nest hole in front of flowers. Note regurgitated pellets of insect remains. Alentejo, Portugal, April.

Roger Powell / European Bee-eater (Merops apiaster) with a bee landing on a branch by its mate. Alentejo, Portugal, May.

Roger Powell / European Bee-eater (Merops apiaster) courting a female by offering her a Small Copper butterfly (Lycaena phlaeas). Alentejo, Portugal, April.

Andy Rouse / 2020VISION / European Hares (Lepus europaeus) boxing, female on right. Wales, UK, June. Sequence 2 of 2. Did you know? A group of hares is known as a drove.

Andy Rouse / 2020VISION / European Hares (Lepus europaeus) boxing, female on right. Wales, UK, June. Sequence 1 of 2.

Andy Sands / Digger Wasp (Cerceris rybyensis) Female carrying two males attempting to displace one another to mate, West sussex, England, UK, July

LYNN M. STONE / Great Egrets (Ardea alba) preening their breeding plumage, at nest. Osceola County, Florida, USA, March.

Paul Harris / 2020VISION / Local resident Roy Peters holding two Adders (Vipera berus) male in foreground female behind, Caesar's Camp, Fleet, Hampshire, England, UK, May 2011. Model released.

Michel Poinsignon / Praying mantis (Mantis religiosa) pair on plant facing each other, Lorraine, France, September.

Michel Poinsignon / Mute swan (Cygnus olor) two adults on water in courtship display, Lorraine, France, January.

Mark Hamblin / 2020VISION / Pair of Common frogs (Rana temporaria) in garden pond, Warwickshire, England, UK, March

Andrew Parkinson / 2020VISION / European brown hare (Lepus europaeus) adult male, running, pursuing a female, Elmley Marshes, Kent, UK, February

Andy Sands / Kingfisher (Alcedo atthis) male passing fish to female spring during courtship behaviour, Hertfordshire, England, UK, March. Sequence 2 of 6.

David Shale / Male and Female glass shrimps on Glass sponge (Hexactinellida) from coral seamount, SW Indian Ridge, Indian Ocean, December 2011

Erlend Haarberg / Male Rock ptarmigan (Lagopus muta) with a female and others standing in row, Iceland, March

Erlend Haarberg / Bar-tailed godwit (Limosa lapponica) courtship display, male in flight, Finnmark, Norway, May

Rolf Nussbaumer / Northern mockingbird (Mimus polyglottos) adult fighting with Golden-fronted Woodpecker (Melanerpes aurifrons) female over Texas Prickly Pear Cactus (Opuntia lindheimeri) Dinero, Lake Corpus Christi, S...

Rolf Nussbaumer / Black-necked stilt (Himantopus mexicanus) pair displaying, Dinero, Lake Corpus Christi, South Texas, USA.

Dave Watts / Mareeba rock wallaby (Petrogale mareeba) family, near Mareeba, Queensland, Australia, November

Chris Gomersall / 2020VISION / Red campion (Silene dioica) flowering in conservation margin next to a crop of Oilseed rape (Brassica napus), RSPB's Hope Farm reserve, Cambridgeshire, England, UK, April. 2020VISION Exhibition. Did y...

Andrew Parkinson / 2020VISION / A male (left) and female Ptarmigan (Lagopus mutus) in winter plumage taking flight from an ice field as a skier passes by, Cairngorms National Park, Scotland, UK, March 2011. 2020VISION Exhibition.

Ben Hall / Great crested grebes (Podiceps cristatus) performing their elaborate courtship ritual at dawn, Cheshire, UK November

Ben Hall / Great crested grebes (Podiceps cristatus) performing courtship ritual at dawn, Cheshire, UK April

Roland Seitre / Spix's Macaw (Cyanopsitta spixii) male and female pair, portrait, captive, critically endangered species, from Brazil

Ben Hall / Long tailed tits (Aegithalos caudatus) pair perched on pine branch in snowfall, Cheshire, UK March

Ben Hall / Shelducks (Tadorna tadorna) pair in flight at dusk, Lancashire, UK

Vladimir Medvedev / Whiskered Auklet (Aethia pygmaea) male and female courtship, Jonah's island, Sea of Okhotsk, Far East Russia, July .

Florian Möllers / Quinling Golden snub nosed monkey (Rhinopitecus roxellana qinlingensis), adult male (right) and female sitting on the ground close to each other. Zhouzhi Nature Reserve, Qinling Mountains, Shaanxi, Ch...

Ross Hoddinott / 2020VISION / Pair of mating soldier beetles (Rhagonycha fulva) on Common ragwort (Senecio jacobaea), Arne RSPB reserve, Dorset, England, UK, August. Did you know? In some areas this insect is called the “bloodsuck...

Martin Willis / Victoria's Riflebird (Ptiloris victoriae) male displaying for female on vine lek, Malanda, Queensland, Australia

Marie Read / Western grebe (Aechmophorus occidentalis) pair swimming, with reflections, Bolsa Chica Ecological Reserve, California, USA, February

Gerrit Vyn / Ruffed grouse (Bonasa umbellus) male displaying neck "ruff". The ruff is most often displayed once a female has been attracted by the males drumming and is present. Okanogan County, Washington, USA Ap...

Alex Mustard / Rock beauty angelfish (Holacanthus tricolor) pair at dusk performing their courtship dance with the larger male circling the female, Georgetown, Grand Cayman, Cayman Islands, British West Indies. Cari...

Alex Mustard / Butter hamlet (Hypoplectrus unicolor) pair spawning at dusk, George Town, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

Piotr Naskrecki / Giant Monkey Frog (Phyllomedusa bicolor) female watching an approaching male, Surinam

Andrew Parkinson / 2020VISION / An adult male Mallard (Anas platyrhynchos) comes in to land, backlit by evening sunlight, Derbyshire, England, UK, March. Did you know? In addition to the colour differences between male and female du...

Sergey Gorshkov / Willow grouse / ptarmigan (Lagopus lagopus) pair in flight, Agapa River, Taimyr Peninsula, Siberia, Russia

Luiz Claudio Marigo / Family of Southern coatis (Nasua nasua) in Atlantic Rainforest, Tijuca National Park, Rio de Janeiro City, Southeastern Brazil.

Markus Varesvuo / Smew, male and female (Mergus albellus) Finland May

Tui De Roy / Blue-footed Booby (Sula nebouxii) sky pointing during courtship dance, Galapagos Islands, Ecuador. Sequence 1 of 3

Bert Willaert / Pair of mating Mouse Opossums (Marmosops cf. noctivagus) hanging from prehensile tail. Ecuador,

Bert Willaert / Amplectant pair of Natterjack Toads (Epidalea / Bufo calamita) with reflection in water. Belgium, Europe, July.

Mark Hamblin / 2020VISION / Greylag goose (Anser anser) pair on edge of loch, near nesting site, Scotland, UK, May 2010

John Abbott / Chilean rose / flame / fire / red-haired tarantula (Grammostola rosea) pair mating, female on left, male on right, from South America

Martin Gabriel / Stag Beetle (Lucanus cervus) pair mating. Bavaria, Germany, June.

Juan Carlos Munoz / Two White Tailed Sea Eagle (Haliaeetus albicilla) fighting in acrobatic flight as Raven (Corvus corax) looks on. Scandinavia, April. 5th, 2010 Euronatur Wildlife photographer competition.

Juan Carlos Munoz / Two White Tailed Sea Eagle (Haliaeetus albicilla) fighting in acrobatic flight as Raven (Corvus corax) looks on and a Herring Gull (Larus argentus) flies past. Scandinavia, April.

Konrad Wothe / Eclectus Parrot (Eclectus roratus) courtship behaviour in rainforest, Cape York Peninsula, North Queensland, Australia, captive

Konrad Wothe / Eclectus Parrot (Eclectus roratus) pair in rainforest, female on right, Cape York Peninsula, North Queensland, Australia, captive

Ben Hall / 2020VISION / Red grouse (Lagopus lagopus scoticus) standing on gritstone boulder with flowering heather (Ericaceae sp), Peak District NP, August 2011. Did you know? While the female grouse is incubating her eggs,...

Andrew Parkinson / 2020VISION / Great crested grebe (Podiceps cristatus) male mating with female who has shown her willingness to mate by lying on the nest site in front of a fishing platform, Derbyshire, UK, March, sequence 2/5

Andrew Parkinson / 2020VISION / Great crested grebe (Podiceps cristatus) pair of adults during part of their elaborate courtship ritual during the very last few rays of evening sunlight, Derbyshire, UK, March.

Andrew Parkinson / 2020VISION / Great crested grebe (Podiceps cristatus) pair of adults during part of their elaborate courtship ritual during the very last few rays of evening sunlight, Derbyshire, UK, March.

Kevin Schafer / Maleo (Macrocephalon maleo) pair on breeding ground, Sulawesi, Indonesia, Endangered

Fabrice Cahez / Great crested grebe (Podiceps cristatus) pair displaying, Vosges, France, March

Alex Mustard / 2020VISION / Two male Common cuttlefish (Sepia officinalis) compete for a female (on right) during courtship, Torbay, Devon, UK, May. 2020VISION Exhibition. 2020VISION Book Plate. Did you know? Cuttlefish have an...

Alex Mustard / 2020VISION / Pair of Common cuttlefish (Sepia officinalis), female in front of male, during spring spawning season, Babbacombe Bay, Torbay, Devon, UK, May

Alex Mustard / 2020VISION / Pair of Common cuttlefish (Sepia officinalis), female in foreground and male behind, note circular mating scars on female caused by the males suckers, Babbacombe Bay, Torbay, Devon, UK, May. Did you k...

Alex Mustard / 2020VISION / Compass jellyfish (Chrysaora hysoscella) swimming over a rocky reef, Plymouth, Devon, UK, August. Did you know? Compass jellyfish change gender throughout their lives, starting off male, and later bec...

Andrew Parkinson / Great crested grebes (Podiceps cristatus) a pair of adults perform their elaborate courtship dance. Derbyshire, UK, March.

Andrew Parkinson / Mute swans (Cygnus olor) pair of adults engaged in a courtship dance, Nottinghamshire, UK, February.

Ernie Janes / Silhouette of Red deer (Cervus elaphus) stag, hind and fawns at sunset, Norfolk, UK

Dave Watts / Eastern grey kangaroo (Macropus giganteus) family group, male, female and large joey, Tasmania, Australia, February

Sandesh Kadur / King cobra (Ophiophagus hannah) cannibalism, male swallowing female on forest floor, Agumbe, Karnatka, India

Sandesh Kadur / King cobra (Ophiophagus hannah) male and female courtship, Agumbe, Karnatka, India, captive