Martin Willis / Victoria's Riflebird (Ptiloris victoriae) male in courtship display, Atherton Tableland, Queensland, Australia. Sequence 2 of 3

Martin Willis / Rainbow Lorikeet (Trichoglossus haematodus) pair preening during courtship, Magnetic Island, Queensland, Australia

Oscar Dewhurst / Red deer (Cervus elaphus) stag roaring, silhouetted under trees at sunrise. Bushy Park, London, UK. September

John Chan / Crenulated fiddler crab (Uca crenulata) waving its major claw at another crab, part of a courtship display, Southern California, USA, June.

John Shaw / Great frigatebird (Phaethon aethereus) male at nest site, with gular sac inflated to attract females. Genovesa Island, Galapagos, May.

John Shaw / Common grackle pair (Quiscalus quiscula) in courtship display. Wakodahatchee Wetlands, Florida, USA, April.

John Shaw / Black-browed albatross pair (Thalassarche melanophris) mutual grooming during copulation. New Island, Falkland Islands, November.

SCOTLAND: The Big Picture / RF - Brown hare, (Lepus europaeus) male pursuing female that is in season, Islay, Scotland, UK., March (This image may be licensed either as rights managed or royalty free.)

SCOTLAND: The Big Picture / RF - Brown hare, (Lepus europaeus), male and female displaying courtship behaviour, Islay, Scotland, UK., March (This image may be licensed either as rights managed or royalty free.)

SCOTLAND: The Big Picture / RF - Black Grouse (Tetrao tetrix), two males fighting on lek , Scotland, UK.April (This image may be licensed either as rights managed or royalty free.)

SCOTLAND: The Big Picture / Brown hare, (Lepus europaeus), group of animals in field, Islay, Scotland, UK., March

Bernard Castelein / Sarus crane (Grus antigone), male displaying, Keoladeo NP, Bharatpur, India

Wim van den Heever / King penguins (Aptenodytes patagonicus) at sunrise. Two males and a female, with the males fighting for the attention of the female. Falklands Islands. 2018 Wildlife Photographer of the Year LUMIX Peo...

Marie Read / Western Grebe (Aechmorphus occidentalis), pair during 'rushing' courtship display in which they run across water's surface in synchrony, near Escondido, California, USA, January.

David Pattyn / Great crested grebe (Podiceps cristatus) adults courting and greeting each other to confirm their bond. Even with the young chicks already out they often show courtship behavior to each other, Valkenh...

Russell Cooper / Mandarin duck drake (Aix galericulata) on the water, showing orange 'sail' feathers which are used when displaying, Southwest London, UK, March.

Stefan Christmann / Adelie penguin (Pygoscelis adeliae) calling during courtship, Atka Bay, Queen Maud Land, Antarctica, December.

David Gallan / Cameratrap video of a male Superb lyrebird (Menura novaehollandiae) courting female on display mound, Australia, July.

David Gallan / Male Satin bowerbird (Ptilonorhynchus violaceus) courting female on suburban street verge, bower filled with blue plastic, Australia, October 2018.

Eric Baccega / Lioness (Panthera leo), aggressively rebuffing male lion banks of the Luangwa river, South Luangwa National Park, Zambia

John Chan / Elegant terns (Thalasseus elegans) courting, Southern California, USA, March.

Michael Hutchinson / Pair of Marsh fritillary butterflies (Euphydryas aurinia) courting on a Buttercup (Ranunculus), Devon, England, UK, June.

Michael Hutchinson / Pair of Marsh fritillary butterflies (Euphydryas aurinia) courting on a Buttercup (Ranunculus), Devon, England, UK, June.

Nick Upton / White stork (Ciconia ciconia) pair performing an up-down display with bill clattering on their nest in an Oak tree, Knepp estate, Sussex, UK, April 2019. This is the first recorded instance of White s...

Stefan Christmann / Emperor penguin (Aptenodytes forsteri) pair in courtship, on sea ice. Atka Bay, Antarctica. May.

Paul Hobson / Red deer (Cervus elaphus) herd during rut in morning light. Derbyshire, England, UK. October.

Donald M. Jones / Northern Pintail (Anas acuta) males flying with female in spring courtship display, Montana

Shane Gross / Nurse sharks (Ginglymostoma cirratum) two in a courtship dance at sunrise in a mangrove area near Eleuthera, Bahamas.

Steven David Miller / Great bowerbird (Chlamydera nuchalis), male showing off treasures whilst female inspects bower. Lake Argyle, Kununurra, Western Australia.

Franco Banfi / Sperm whale (Physeter macrocephalus) young male trying to copulate with a female. The calf of the female was in the way so the male is trying to chase it away. Dominica.

Tui De Roy / Blue-footed booby (Sula nebouxii), pair in courtship display. Punta Pitt, San Cristobal Island, Galapagos. April 2017.

Alex Mustard / Yellowtail tang (Zebrasoma xanthurum) male courting a female prior to spawning at dusk on a coral reef. Temple, Ras Umm Sid, Sharm El Sheikh, Sinai, Egypt. Red Sea.

Sandesh Kadur / Pair of Waved albatrosses (Phoebastria irrorata) displaying, tapping beaks, Galapagos Islands, Ecuador.

Nick Garbutt / Andean cock-of-the-rock (Rupicola peruvianus), male displaying at lek in tree. Manu Biosphere Reserve, Amazonia, Peru.

Konrad Wothe / Pair of European nuthatches (Sitta europaea) mating, Bavaria, Germany, April.

John Chan / Male California Least Tern (Sternula antillarum browni) courting a female, presenting a fish before chasing off another male, Huntington Beach, California, USA, May.

Sergey Gorshkov / Black Grouse (Tetrao tetrix) males fighting at lek in the snow, Tver, Russia. April

John Waters / Male Shoveler (Anas clypeata) chasing other males away from his mate, Greyale RSPB Reserve, Somerset Levels, England, UK, February.

Tui De Roy / Short tailed albatross (Phoebastria albatrus) subadults courting, one with fish-hook and monofilament line embedded in throat. Tsubamezaki, Torishima Island, Japan. December.

Yashpal Rathore / Kottigehar dancing frog (Micrixalus kottigeharensis) male calling and displaying to attract female by waving foot, Agumbe, Western Ghats, India.

Yashpal Rathore / Kottigehar dancing frog (Micrixalus kottigeharensis) male calling and displaying to attract female by waving foot, Agumbe, Western Ghats, India.

Philippe Clement / Pair of Black-tailed godwits (Limosa limosa) courting and mating in wetland, Belgium, April

Tui De Roy / Waved albatross (Phoebastria irrorata) pair in courtship display at nest site, Punta Suarez, Espanola Island, Galapagos

Tui De Roy / Atlantic yellow-nosed albatross (Thalassarche chlororhynchos) courtship display sequence. Gough Island, Gough and Inaccessible Islands UNESCO World Heritage Site, South Atlantic.

George Sanker / Mallard (Anas platyrhynchos) pair greeting on snow-covered pond. Acadia National Park, Maine, USA.

George Sanker / Mallard (Anas platyrhynchos)pair greeting on snow-covered pond. Acadia National Park, Maine, USA.

Tui De Roy / Blue-footed Booby (Sula nebouxii) performing foot-lifting courtship display, Seymour Island, Galapagos Islands, Ecuador

Tui De Roy / Blue-footed Booby (Sula nebouxii) performing foot-lifting courtship display, Seymour Island, Galapagos Islands, Ecuador

Ann & Steve Toon / Kori bustard (Ardeotis kori) male courtship display, Kgalagadi Transfrontier Park, Northern Cape, South Africa.

Tony Wu / Fireflies (Luciola parvula himebotaru) flashing at night for courtship and reproduction. Gifu, Japan. Composite image

Andy Rouse / Pair of Great crested grebes (Podiceps cristatus) courting, Cardiff, Wales, UK, March.

Andy Rouse / Pair of Great crested grebes (Podiceps cristatus) courting, Cardiff, Wales, UK, March.

Fred Olivier / Group of Magellanic penguins (Spheniscus magellanicus) displaying on a beach, Gypsy Cove, Stanley, Falkland Islands.

Fred Olivier / Magellanic penguins (Spheniscus magellanicus) displaying on a beach, Gypsy Cove, Stanley, Falkland Islands.

Fred Olivier / Close-up of a pair of Black browed albatrosses (Thalassarche melanophris) mutual grooming, New Island, Falkland Islands.

Fred Olivier / Pair of Black browed albatrosses (Thalassarche melanophris) display bonding, touching beaks, New Island, Falkland Islands.

Fred Olivier / Pair of Blue footed boobies (Sula nebouxii) courting, with the male picking up and offering grass, Isla Lobos de Terra, Peru.

Peter Bassett / Pair of Gentoo penguins (Pygoscelis papua) courting and attempting to mate, Neko Harbour, Andvord Bay, Graham Land, Antarctica.

Peter Bassett / Male Southern elephant seal (Mirounga leonina) shifting position on a beach, surrounded by females, almost crushing a pup, Gold Harbour, South Georgia.Gold Harbour, South Georgia.

SCOTLAND: The Big Picture / Two male Black grouse (Tetrao tetrix) displaying at a lek, Cairngorms National Park, Scotland, UK, April.

James Dunbar / Male Orb-weaving spider (Araneus) courting a female near a dead fly, Bristol, England, UK, September.

Nick Upton / Close up view of a Marbled white butterfly (Melanargia galathea) nectaring on a Field scabious (Knautia arvensis) flower, with another trying to court with it, Wiltshire, England, UK, July.

Nick Upton / Slow motion cllip of a Marbled white butterfly (Melanargia galathea) nectaring on a Creeping thistle (Cirsium arvense) flower, with another trying to court with it, Wiltshire, England, UK, July.

Tui De Roy / Waved albatross (Phoebastria irrorata) pair displaying on coast Galapagos, Ecuador. Critically Endangered species.

Tui De Roy / Waved albatross (Phoebastria irrorata) pair in courtship display, Galapagos, Ecuador. Critically Endangered species.

Tui De Roy / Great frigatebird (Fregata minor) male displaying inflated gular sac, Galapagos, Ecuador.

David Pattyn / Great crested grebe (Podiceps cristatus) fluffing up its feathers, during courtship dance, whilst its mate dives underwater, The Netherlands. April.

David Pattyn / Black necked grebe (Podiceps nigricollis) pair chasing away another grebe during the courtship season. The Netherlands.April 2014

David Pattyn / Black necked grebe (Podiceps nigricollis) pair during courtship performing their courtship dance in the mating season. The Netherlands. April 2014

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) pair swimming away during their courtship dance. The Netherlands.March 2014

David Pattyn / Black necked grebe (Podiceps nigricollis) pair performing their courtship dance in the mating season. The Netherlands.March 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,...

David Pattyn / Black necked grebe (Podiceps nigricollis) pair mimicking each others movements in their courtship rituals. The Netherlands.March 2014

David Pattyn / Great crested grebe (Podiceps cristatus) performing courtship dance with one emerging from water right in front of the other which has fluffed up its feathers. The Netherlands. April.

David Pattyn / Great crested grebe (Podiceps cristatus) pair wimming very fast next to each other and shaking their heads as a part of their courtship dance. The Netherlands. April.

Fred Olivier / Pair of Adelie penguins (Pygoscelis adeliae) displaying to one another, Antarctica.

Ingo Arndt / Vogelkop bowerbird (Amblyornis inornatus) decoration material (fruit and beetle elytra ) collected in order to attract females to his bower, Arfak Mountains, Irian Jaya, New Guinea, Indonesia.

Ingo Arndt / Vogelkop bowerbird (Amblyornis inornatus) decoration material (fungus) collected in order to attract females to his bower, Arfak Mountains, Irian Jaya, New Guinea, Indonesia.

Ingo Arndt / Vogelkop bowerbird (Amblyornis inornatus) decoration material (blue rotten wood) collected in order to attract females to his bower, Arfak Mountains, Irian Jaya, New Guinea, Indonesia.

Ingo Arndt / Bower of Vogelkop Bowerbird (Amblyornis inornatus) decorated with various types of leafs, beetle wing covers, black and brown fungi, red flowers and blue berries, Arfak Mountains, West Papua, Indonesi...

Ingo Arndt / Great Bowerbird (Chlamydera nuchalis) male at courting bower, Litchfield National Park, Australia.

Ingo Arndt / Bower of Vogelkop bowerbird (Amblyornis inornatus) front entrance of bower decorated with red fruit and acorns, Arfak Mountains, West Papua, Indonesia.

Ingo Arndt / Male Vogelkop Bowerbird (Amblyornis inornatus) constructing bower roof. Arfak Mountains, West Papua, Indonesia.

Ingo Arndt / Ostrich (Struthio camelus) pair courtship display, Masai Mara National Reserve, Kenya, Africa

John Waters / Female Grayling (Thymallus thymallus) pursued by several males, River Kennet, Berkshire, England, UK. March.

Tony Wu / Humpback whales (Megaptera novaeangliae) male during a competetive heat run. Vava'u, Tonga, South Pacific.

Nick Saunders/ BIA / Ruddy Duck (Oxyura jamaicensis) male in courtship display, Saskatchewan, Canada

Steve Gettle / Great Egret (Ardea alba) in courtship display, North America

Steve Gettle / Western Grebe (Aechmophorus occidentalis) pair in courtship dance, North Dakota

Jack Dykinga / Sandhill cranes (Grus canadensis) mating dance at sunset, Bosque del Apache National Wildlife Refuge, New Mexico, USA, December.

Markus Varesvuo / Japanese / Red-crowned crane (Grus japonicus) two calling and dancing, part of bonding and courtship display, Hokkaido Japan February

David Tipling / King penguins (Aptenodytes patagonicus) pair interacting, part of courtship, Gold Harbour South Georgia, January

David Tipling / Wandering albatross (Diomedea exulans) displaying to bird flying overhead on Albatross Island, South Georgia, January

David Tipling / Wandering albatross (Diomedea exulans) a pair displaying at dusk, Albatross Island, South Georgia January

David Tipling / Wandering albatross (Diomedea exulans) pair displaying at dusk in ritual bonding behaviour, Albatross Island in Bay of Isles, South Georgia January