David Pattyn / Black necked grebe (Podiceps nigricollis) adult bird in breeding plumage approaching its partner in a vertical position during their courtship dance. The Netherlands.April 2014

David Pattyn / Black necked grebe (Podiceps nigricollis) adult bird spreading its wings and waiting for the submerged partner to appear in front and perform the courtship dance. This is early in the breeding season,...

Enrique Lopez-Tapia / Woman with lip plate, which signifies she is a married woman, Mursi tribe, Mago National Park. Ethiopia, November 20144

David Pattyn / Black necked grebe (Podiceps nigricollis) portrait of an adult approaching its partner during their courtship dance. The Netherlands. April 2014

David Pattyn / Black necked grebe (Podiceps nigricollis) adult spreading its wings during the courtship dance. This bird is waiting for the submerged partner to emerge from the water and perform a dance in front. Th...

David Pattyn / Great crested grebe (Podiceps cristatus) portrait of a bird approaching its partner during courtship. The Netherlands. April.

David Pattyn / Black necked grebe (Podiceps nigricollis) adult bird spreading its wings in anticipation of the partner during courtship. The Netherlands.April 2014

David Pattyn / Great crested grebe (Podiceps cristatus) portrait of a bird approaching its partner during courtship. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) adult bird approaching its partner with plant material to perform their 'weed dance'. Mating season. The Netherlands.May 2014

Terry Whittaker / 2020VISION / Avocet (Recurvirostra avosetta) in mist on grazing marsh at dawn with cattle grazing in the background, Thames Estuary, Elmley Marshes RSPB reserve, North Kent, UK,, April 2011. Photographer quote: 'G...

Ashley Cooper / Low angle view of climber with crampons on boot, Aonach Mhor, Scotland, UK. March 2004

Ashley Cooper / Mont Blanc Du Tacul with mountaineers climbing the peak. From the Aiguille Du midi, above Chamonix, France, September 2014

Ashley Cooper / Little auks (Alle alle) at a nesting colony at Sallyhamna, Spitsbergen, Svalbard, Norway. July.

Ashley Cooper / Little auks (Alle alle) at a nesting colony at Sallyhamna, Spitsbergen, Svalbard, Norway. July.

David Pattyn / Gannet (Morus bassanus) landing and with partner greeting it, Great Saltee, Saltee Islands, County Wexford, Republic of Ireland. June

David Pattyn / Gannet (Morus bassanus) landing and with partner greeting it, Great Saltee, Saltee Islands, County Wexford, Republic of Ireland. June

David Pattyn / Gannet (Morus bassanus) landing and with partner greeting it, Great Saltee, Saltee Islands, County Wexford, Republic of Ireland. June

David Pattyn / Gannet (Morus bassanus) landing and being welcomed by its partner Great Saltee, Saltee Islands, County Wexford, Republic of Ireland. June

Guy Edwardes / Northern gannet (Morus bassanus) bringing nesting material to its partner, Great Saltee Island, County Wexford, Republic of Ireland, June., June.

Guy Edwardes / Northern gannet (Morus bassanus) bringing nesting material to its partner, Great Saltee Island, County Wexford, Republic of Ireland, June., June.

David Pattyn / Great crested grebe (Podiceps cristatus) with crest erected and spreading its wings during a courtship performance for its partner Den Oever, The Netherlands. July

Dave Bevan / Black-headed gull (Chroicocephalus ridibundus) bringing nesting material to partner on a nest, Gloucestershire, England, UK. May.

Frederique Olivier / Gentoo penguins (Pygoscelis papua) courting, the male bringing a stone to his partner, Aitcho Island, South Shetland Islands.

Nick Upton / Female Common/Eurasian crane (Grus grus) 'Chris', released by the Great Crane project in 2010, returning to her nest in a sedge marsh to relieve her partner 'Monty' of incubation duties, Slimbridge, G...

Nick Upton / Male Common/Eurasian crane (Grus grus) 'Monty', released by the Great Crane project in 2010, feeding one of his chicks, with his partner 'Chris' foraging nearby, watched by a second chick, Slimbridge,...

Nick Upton / Male Common/Eurasian crane (Grus grus) 'Monty', released by the Great Crane project in 2010, feeding one of his chicks, with his partner 'Chris' foraging nearby, watched by a second chick, Slimbridge,...

Nick Upton / Female Common/Eurasian crane (Grus grus) 'Chris', released by the Great Crane project in 2010, feeding one of her chicks, with her partner 'Monty' foraging nearby, Slimbridge, Gloucestershire, England...

Frederique Olivier / Cape petrel (Daption capense) trying to groom and bond with its partner, Antarctica.

Frederique Olivier / Cape petrel (Daption capense) trying to groom and bond with its partner, Antarctica.

Juergen & Christine Sohns / Great Blue Heron (Ardea herodias) taking flight from nest while partner displays, Wakodahatchee Wetlands, Florida. Sequence 3 of 3

David Pattyn / Gannet (Morus bassanus) male offering nesting material to its partner in the breeding season, part of courtship, Great Saltee, Saltee Islands, County Wexford, Republic of Ireland, June.

Alex Mustard / Whip coral partner shrimp (Dasycaris zanzibarica) on whip coral. This is an unusual orange variety. Komodo Island, Komodo National Park, Indonesia.

Danny Green / Atlantic Puffin (Fratercula arctica) covered by mud from its partner digging out their nesting chamber / burrow, Skomer Island, Wales, UK, April

David Pattyn / Great Crested Grebe (Podiceps cristatus) spreading its wings wide and keeping crest erect to impress its partner during courtship. The Netherlands. April.

David Pattyn / Great Crested Grebe (Podiceps cristatus) spreading its wings wide and keeping crest erect to impress its partner during courtship. The Netherlands. April.

Richard Herrmann / Osprey (Pandion haliaetus) landing on nest near partner, Cedros Island, Baja California, Mexico

Andy Rouse / Gentoo penguin (Pygoscelis papua) in sandstorm on beach, Saunders Island, Falkland Islands.

Steve O. Taylor (GHF) / Wife of Toubou guide in Sigadine, Niger, 2005.

Tui De Roy / Waved albatross (Phoebastria irrorata) performing display, courting partner with colony in background. Punta Cevallos, Espanola (Hood) Island, Galapagos, Ecuador, May. Sequence 1 of 3.

Tui De Roy / Waved albatross (Phoebastria irrorata) performing display, courting partner with colony in background. Punta Cevallos, Espanola (Hood) Island, Galapagos, Ecuador, May. Sequence 3 of 3.

Tui De Roy / Waved albatross (Phoebastria irrorata) performing display, courting partner with colony in background. Punta Cevallos, Espanola (Hood) Island, Galapagos, Ecuador, May. Sequence 2 of 3.

Philip Stephen / MFV coming alongside partner vessel to start pair trawling operations. North Sea, 2008. Property released.

Philip Stephen / MFV coming alongside partner vessel to start pair trawling operations. North Sea, 2009. Property released.

Philip Stephen / Crewmen shakle trawl warp to the net, with partner vessel coming alongside in the background, for pair trawling. North Sea, September 2008. Model released.

Nick Upton / Male Coot (Fulica atra) fighting a rival in a territorial dispute, as its partner swims towards them, Wiltshire, UK, October

Philip Stephen / MFV "Harvester" coming alongside partner vessel to start pair trawling operations. North Sea, September 2008. Property Released.

Philip Stephen / MFV coming alongside partner vessel to start pair trawling operations. North Sea, 2009. Property released.

Andrew Parkinson / 2020VISION / Great crested grebe (Podiceps cristatus) adult in profile calling to its partner, Derbyshire, UK, March

Adrian Davies / Great Blue Heron (Ardea herodias) displaying to its partner on their nest Venice Rookery, Florida, USA, January.

Juergen Freund / Banded shrimp goby (Cryptocentrus cinctus) yellow morph with snapping shrimp partner (Alpheus sp.) Papua New Guinea.

Edwin Giesbers / White Stork (Ciconia ciconia) coming in to land while its partner sits on nest. The Netherlands, April.

Philip Stephen / Crewman throwing heaving line across to partner vessel during pair trawl operations, North Sea, January 2010.

Fred Bavendam / Metallic Shrimp-goby (Amblyeleotris latifasciata) keeps watch while its Snapping Shrimp (Alpheus sp) partner works on their burrow, Bali, Indonesia

Juergen Freund / Egg / Allied partner cowrie {Dentiovula dorsuosa} camouflaged on soft coral, Indo-pacific

Juergen Freund / Egg / Allied partner cowrie {Dentiovula dorsuosa} camouflaged on soft coral, Indo-pacific

Philip Stephen / MFV coming alongside partner vessel to start pair trawling operations. North Sea, 2009. Property released.

Philip Stephen / MFV coming alongside partner vessel to start pair trawling operations. North Sea, 2008. Property released.

Paul Hobson / Cape Barren / Cereopsis Goose (Cereopsis novaehollandiae) one bird biting its partner, Kangaroo Island, South Australia

Scott Leslie / Tree Swallow (Tachycineta bicolor) landing near nest cavity with partner calling, Tobeatic Wilderness Area, Nova Scotia, Canada

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

Tui De Roy / Chatham Albatross (Thalassarche eremita) courting pair, critically endangered, The Pyramid, Chatham Islands

Tui De Roy / Chatham Albatross (Thalassarche eremita) affectionate pair, critically endangered, The Pyramid, Chatham Islands

Tui De Roy / Chatham Albatross (Thalassarche eremita) portrait of two, critically endangered, The Pyramid, Chatham Islands

David Pike / Japanese crane courtship display {Grus japonensis} Hokkaido, Japan, annual mating season between February / March. Cranes are generally monogamous, mating with same partner for life - these dancing r...

Gary Smith / Sandwich Tern {Sterna sandvichensis} chick with adult calling to partner bird for food, Blakeney Point, Norfolk, UK.

Hiroya Minakuchi / Whip Coral Partner Shrimp (Dasycaris zanzibarica), Sulu Sea, Borneo, Malaysia

Michael Quinton / Common Raven (Corvus corax) male mates with a female in her nest while her partner is away, North America

Michael Quinton / Common Raven (Corvus corax) male mates with a female in her nest while her partner is away, North America

Tui De Roy / Flightless Cormorant (Phalacrocorax harrisi) bringing food to partner, Punta Albemarle, Isabela Island, Galapagos Islands, Ecuador

Tui De Roy / Flightless Cormorant (Phalacrocorax harrisi) bringing food to partner, Punta Albemarle, Isabela Island, Galapagos Islands, Ecuador

Heidi & Hans-Juergen Koch / Edible Snail (Helix pomatia) pair with love dart between them, a calcium carbonate organ used to stimulate the partner during courtship, Aardenburg, Netherlands

Philip Stephen / Crewmen onboard trawler "Carisanne" passing the trawl wire to their partner vessel at the commencement of their trawl operations in the North Sea. June 2007.

Roberto Rinaldi / Two nudibranchs / sea slugs (dorids), New South Wales, Australia. ^^^Dorids are the largest group of nudibranchs, typically they have a pair of rhinopores at the front of the head used to locate food...

Paul Harcourt Davies / Tree lungwort (Lobaria pulmonaria), a large epiphytic lichen consisting of an ascomycete fungus and a green algal partner living together in a symbiotic relationship with a cyanobacterium, growing in...

Doug Perrine / Day octopus (Octopus cyanea) sitting on Lobe coral (Porites lobata) and placing tentacles beneath it to flush out fish, shadowed by Manybar goatfish (Parupeneus multifasciatus), their hunting partner...

David Hall / Male Rock Crab (Cancer irroratus) holding his female partner closely until ecdysis (moulting) occurs, at which time copulation becomes possible. Cape Ann, Massachusetts, USA. Atlantic Ocean.

David Hall / Two Indigo hamlets (Hypoplectrus indigo) mating, they are simultaneous hermaphrodites, the individual acting as a male is wrapping around his partner, inducing her to release her eggs, Belize, Caribbe...

David Hall / Two Indigo hamlets (Hypoplectrus indigo) mating, they are simultaneous hermaphrodites, the individual acting as a male is wrapping around his partner, inducing her to release her eggs, Belize, Caribbe...

SCOTLAND: The Big Picture / Wader scrapes, shallow pools, created in wetland habitat, on Northwoods Rewilding Network land partner, Ballinlaggan, Cairngorms National Park, Scotland, UK. December, 2020.

SCOTLAND: The Big Picture / Digger being used to create wader scrapes, shallow pools, in wetland habitat, on Northwoods Rewilding Network land partner, Ballinlaggan, Cairngorms National Park, Scotland, UK. December, 2020.

Jasper Doest / Northern Gannet (Morus bassanus) defending partner, Saltee Island, Republic of Ireland

David Tipling / Barn owl (Tyto alba), leucistic male with female partner, perched on fence post, Cley, North Norfolk, UK. March.

David Pattyn / Great crested grebe (Podiceps cristatus) spreading its wings to impress its partner during courtship display, The Netherlands, Europe. March.

David Pattyn / Great crested grebe (Podiceps cristatus) spreading its wings to impress its partner during courtship display, The Netherlands, Europe. March.

David Pattyn / Great crested grebe (Podiceps cristatus) spreading its wings to impress its partner during courtship display, The Netherlands, Europe. March.

David Pattyn / Pair of Great crested grebes (Podiceps cristatus) during courtship display, one grebe is running over its partner in an attempt to impress, The Netherlands, Europe. March.

Ugo Mellone / Hooded grebe (Podiceps gallardoi) pair, adult greeting partner with chick on nest, Strobel plateau, Santa Cruz, Patagonia, Argentina. Cropped.

David Tipling / Slavonian grebe (Podiceps auritus) pair in courtship display, Loch Kinellan, Scotland Highlands, UK. May.

David Tipling / Slavonian grebe (Podiceps auritus) mating pair on Loch Kinellan, Highlands, Scotland, UK. May.

David Fleetham / Allied partner cowry (Aclyvolva lanceolata) on whip coral, Philippines. The mantel of the cowry imitates the polyps of the coral when they are open and feeding.

Eric Baccega / Portrait of a Kayan Lahwi woman with her husband. The Long Neck Kayan (also called Padaung in Burmese) are a sub-group of the Karen ethnic people from Burma. They wear spiral coils around their neck a...

Konrad Wothe / Great crested grebes (Podiceps cristatus) pair courtship display, Bavaria, Germany. April.

Konrad Wothe / Great crested grebes (Podiceps cristatus) pair courtshipdisplay, Bavaria, Germany.

Doug Gimesy / Wildlife rescuer and carer Rena Gaborov with orphaned eastern grey kangaroos (Macropus giganteus) in the burnt-out yard at her mother in law's property at Sarsfield. Rena and her partner Joseph had to...

Doug Gimesy / Orphaned Eastern grey kangaroos (Macropus giganteus) in the burnt-out yard at wildlife rescuer and carer Rena Gaborov mother's property at Sarsfield. Rena and her partner Joseph had to evacuate their...