Doug Allan / Emperor penguin males incubating eggs huddle for warmth at -40 degrees centigrade, winter, Antarctica. Green is excrement on snow. {Aptenodytes forsteri}

Doug Allan / Emperor penguin {Aptenodytes forsteri} males huddle for warmth in minus 40 degrees centigrade while incubating eggs in winter, Antarctica Winter extreme cold survival birds seabirds nesting-behaviour

Morley Read / Slow motion clip of a Spiny orb-weaver (Micrathena sp.) weaving a silk nest to protect its eggs, the nest is suspended from a thread to isolate it from predators, Amazon rainforest, Ecuador. Filmed at...

Marie Read / Arctic terns (Sterna paradisaea), two in flight over nesting colony in field of buttercups (Ranunculus sp.), Keflavik, Iceland. Digital canvas expansion.

Ralph Pace / Olive Ridley Sea Turtle (Lepidochelys olivacea) females coming ashore to nest during arribada, Playa de Escobilla Sanctuary, Oaxaca, Mexico

Nick Upton / Pair of White storks (Ciconia ciconia) mating on their nest, Knepp Castle Estate, Sussex, England, UK, April. This is the first recorded instance of White storks nesting in the UK for several hundreds...

Nick Upton / Pair of White storks (Ciconia ciconia) arranging nest material on their nest, Knepp Castle Estate, Sussex, England, UK, April. This is the first recorded instance of White storks nesting in the UK for...

Nick Upton / Pair of White storks (Ciconia ciconia) arranging nest material on their nest, Knepp Castle Estate, Sussex, England, UK, April. This is the first recorded instance of White storks nesting in the UK for...

Nick Upton / White stork (Ciconia ciconia) pair mating on their nest at sunset, Knepp estate, Sussex, UK, April 2019. This is the first recorded instance of White storks nesting in the UK for several hundreds of y...

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...

Nick Upton / White stork (Ciconia ciconia) male landing with nest material and joining his mate on their nest in an Oak tree at sunset, Knepp estate, Sussex, UK, April 2019. This is the first recorded instance of...

Sven Zacek / Ural owl (Strix uralensis) female on nest, male landing with twig in beak. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) male presenting prey to nesting mate. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) female feeding at nest on rodent prey presented by mate. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) female on the nest with nestling hidden under wing. Tartumaa, Southern Estonia. April.

Sven Zacek / Ural owl (Strix uralensis) female on nest in tree stump. Tartumaa, Southern Estonia. April.

Sven Zacek / Black woodpecker (Dryocopus martius) excavating nest hole. Valgamaa, Southern Estonia. April.

Brian Bevan / Long tailed tit (Aegithalos caudates) nest building, Bedfordshire, England, UK, April.

Steven David Miller / Red-collared lorikeet (Trichoglossus rubritorquis) pair examining hole in Eucalyptus as a potential nesting hollow. Katherine, Northern Territory, Australia.

Tui De Roy / Green turtle (Chelonia mydas) female digging nest, North coast, Santa Cruz Island, Galapagos

Tui De Roy / Flightless cormorant (Phalacrocorax harrisi), two on rock. Bird drying wings in foreground with other sitting on nest in background. Cape Douglas, Fernandina Island, Galapagos.

Tui De Roy / Red-footed booby (Sula sula), pair nest building in tree. Darwin Bay, Genovesa Island, Galapagos.

Philippe Clement / Great cormorant (Phalacrocorax carbo) bringing twig to nest in breeding colony, Belgium, March.

Dave Bevan / Common wasp (Vespula vulgaris) adding material to nest, Carmarthenshire, Wales, UK, July.

Dave Bevan / Female Chaffinch (Fringilla coelebs) bringing moss to nest and incorporating it into nest before flying out of frame, Carmarthenshire, Wales, UK, May.

Dave Bevan / Female Chaffinch (Fringilla coelebs) shaping nest with her body and wings, Carmarthenshire, Wales, UK, May.

David Perpinan / Male Lapwing (Vanellus vanellus) arriving at nest to incubate eggs, female leaves, Scottish Borders, Scotland, UK, June.

David Perpinan / Female Rock sparrow (Petronia petronia) feeding chick inside nest, filmed with an infrared camera, Spain, June.

Claudio Contreras / Caribbean Flamingo (Phoenicopterus ruber) building up mud whilst brooding egg, breeding colony, Ria Lagartos Biosphere Reserve, Yucatan Peninsula, Mexico, June, Finalist in the Portfolio Category of...

Frederique Olivier / Adelie penguin (Pygoscelis adeliae) stealing rock from another penguin for its nest, Adelie Land, Antarctica, January.

Francisco Marquez / Penduline tit (Remiz pendulinus) building a nest, Prespa National Park, Prespes, Greece, May.

Terry Whittaker / Water vole (Arvicola amphibius) swimming underwater, dragging nesting material back to its burrow, Kent, England, UK. October.

Frederique Olivier / Chinstrap penguin (Pygoscelis antarcticus) moving a feather in its nest, Aitcho Island, South Shetland Islands.

Frederique Olivier / Chinstrap penguin (Pygoscelis antarcticus) adding a stick to its nest and fighting with a neighbouring pair, Aitcho Island, South Shetland Islands.

Frederique Olivier / Close-up of a Light-mantled sooty albatross (Phoebetria palpebrata) building its nest, Macquarie Island, Sub-Antarctic Australia.

Ingo Arndt / Red wood ant (Formica rufa) carrying construction material to anthill (fir needles), Germany.

Ingo Arndt / Cape gannets (Morus capensis / Sula capensis) at nesting colony, zooming from tight to wide shot, Lamberts Bay, South Africa, December

Ingo Arndt / Olive ridley sea turtles (Lepidochelys olivacea) digging their nests by night with stars during an arribada (mass nesting event) to lay eggs, Pacific Coast, Ostional, Costa Rica.

Ingo Arndt / Olive ridley sea turtles (Lepidochelys olivacea) females coming ashore at twilight during an arribada (mass nesting event) to lay eggs, Pacific Coast, Ostional, Costa Rica.

Ingo Arndt / Olive ridley sea turtles (Lepidochelys olivacea) females coming ashore during an arribada (mass nesting event) to lay eggs, Pacific Coast, Ostional, Costa Rica.

Ingo Arndt / King Penguin (Aptenodytes patagonicus) rookery crowded with nesting birds incubating eggs or protecting their small chicks, Salisbury Plain, South Georgia Island, February 2011

Ingo Arndt / Cape Gannet (Sula capensis) perched on a rock whilst calling, nesting colony, Lamberts Bay, South Africa.

Ingo Arndt / Magellanic penguin in nest hole {Spheniscus magellani} Patagonia, Chile, South America

Ingo Arndt / Purple Heron (Ardea purpurea) pair courting and building nest in reeds, Germany

Danny Green / Atlantic Puffin (Fratercula arctica) looking down a nesting chamber, Skomer Island, Wales, UK, May

Danny Green / Atlantic Puffin (Fratercula arctica) coming out of its burrow with a gift, Skomer Island, Wales, UK, May

Pedro Narra / Green turtle (Chelonia mydas) female digging nest on beach at night, Guinea Bissau. Endangered species. 3rd Place in the SOS Especes Menacees / SOS Endangered Species Portfolio category of the Terre S...

Pedro Narra / Green Turtle (Chelonia mydas) returning to sea, Bissagos Islands, Guinea Bissau. Endangered species. 3rd Place in the SOS Especes Menacees / SOS Endangered Species Portfolio category of the Terre Sau...

Pedro Narra / Man and woman undertaking monitoring work measuring Green turtle (Chelonia mydas) nests as the the female digs it, Bissagos Islands, Guinea Bissau. Endangered species. 3rd Place in the SOS Especes M...

Pedro Narra / Green turtle (Chelonia mydas) returning to see after egg laying, e to open sea after digging nest. Bissagos Islands, Guinea Bissau. Endangered species. 3rd Place in the SOS Especes Menacees / SOS End...

Bence Mate / Osprey (Pandion haliaetus) in flight with nesting material, Hungary, July. Nominated in the Telephoto category of the Terre Sauvage Nature Images Awards competition 2015.

Charlie Summers / Adelie Penguin (Pygoscelis adeliae) carrying stolen rock from another nest in rookery, Peterman Island, Antarctica, November.

Jack Dykinga / Great horned owl (Bubo virginianus) chick nesting in Saguaro cactus (Carnegiea gigantea), Santa Catalina Mountains, Arizona, USA, May.

Espen Bergersen / Atlantic puffin (Fratercula arctica) two birds fighting at nesting ground, Hornoya bird cliff, Finnmark, Norway. March.

Ole Jorgen Liodden / Barn swallow (Hirundo rustica) in mud collecting nesting material, collecting nesting material, with golden bokeh affect in puddle, Svalbard, Norway, June.

Alan Murphy / Great Egret (Ardea alba) carrying nesting material, Texas

Hanne & Jens Eriksen / Ruppell's weaver (Ploceus galbula) male building nest, Oman, May

Denis-Huot / Village weaver bird (Ploceus cucullatus) male building a nest after the rains, Masai-Mara Game Reserve, Kenya. February.

Tui De Roy / Little blue / fairy penguin (Eudyptula minor) pair courting near nesting burrow, Neck Game Reserve, Bruny Island, Tasmania, Australia, December.

Mark Hamblin / 2020VISION / Jackdaw (Corvus monedula) taking a bundle of wool into a nest hole in tree, Inverness-shire, Scotland, UK, April 2011

Mark Hamblin / 2020VISION / Jackdaw (Corvus monedula) pair at their nest hole, one pecking the other for attention, the other quivering its tail, Inverness-shire, Scotland, April 2011

Peter Cairns / 2020VISION / Northern gannets (Morus bassanus) in flight at nesting colony on cliffs, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, June

Mark Hamblin / 2020VISION / Jackdaw (Corvus monedula) pulling a very long twig into a small nest hole, Inverness-shire, Scotland, UK, April 2011

Markus Varesvuo / Guillemot (Uria aalge) flock in flight over nesting colony on rocks, Norway, July 2008

Ammonite / Close-up of Buff-tailed bumble bee (Bombus terrestris) repairing a wax cell containing eggs inside nest, France, May.

Ammonite / Close-up of Buff-tailed bumble bee (Bombus terrestris) repairing a wax cell containing eggs inside nest, France, May.

Ammonite / Close-up of Buff-tailed bumble bee (Bombus terrestris) nest building, France, May.

Ammonite / Buff-tailed bumble bee (Bombus terrestris) nest building, France, May.

Ammonite / Buff-tailed bumble bee (Bombus terrestris) nest building, France, May.

Ammonite / Close-up of a Buff-tailed bumble bee (Bombus terrestris) inside nest, nest building and fanning wings to keep the nest at the correct temperature, France, May.

Ammonite / Close-up of a Buff-tailed bumble bee (Bombus terrestris) nest building, France, May.

Ammonite / Two male Mining bees (Andrena praecox) trying to reach a female bee in a hole, France, March.

Ammonite / Two male Mining bees (Andrena praecox) attacking a third male bee emerging from a hole with orchid pollinia attached, France, March.

Staffan Widstrand / Polar Bear (Ursus maritimus) mobbed by possibly a Skua, Svalbard, Norway, July

Yukihiro Fukuda / Male Japanese giant salamander (Andrias japonicus) protecting his eggs inside his nest, Japan, October

Yukihiro Fukuda / Male Japanese giant salamander (Andrias japonicus) protecting his eggs inside his nest, Japan, September

Roger Powell / Stone curlew (Burhinus oedicnemus) approaching nest of two eggs, Guerreiro, Castro Verde, Alentejo, Portugal, April

Roger Powell / Cattle egret (Bubulcus ibis) in flight carrying a large stick to its nest, Guerreiro, Castro Verde, Alentejo, Portugal, May

Tui De Roy / Sparkling violetear hummingbird (Colibri coruscans) incubating eggs at nest, Andean cloud forest, Ecuador

Tui De Roy / Great frigatebird (Fregata minor) male guarding single chick. Punta Cevallos, Espanola Island, Galapagos, Ecuador, May.

Tui De Roy / Flightless Cormorant (Nannopterum / Phalacrocorax harrisi) with nesting material. Banks Bay, Isabela Island, Galapagos Islands, Ecuador, December.

Loic Poidevin / Yellow warbler (Dendroica petechia) at nest, Pointe Pelee, Ontario, Canada, May

Mark Hamblin / 2020VISION / Barn swallow (Hirundo rustica) collecting mud for nest building, June, Scotland, UK

Kim Taylor / Red mason bee (Osmia rufa) female in flight carrying mud to nest, Surrey, UK, April

Konrad Wothe / Resplendent Quetzal (Pharomachrus mocinno costaricensis) male tail feathers hanging out of the nest, Costa Rica

Fergus Gill / 2020VISION / Barn Swallow (Hirundo rustica) feeding a fledgling on a wire. Perthshire, Scotland, September. Did you know? Swallows have long had a close association with humans - nesting in the eaves of buildings...

Markus Varesvuo / Osprey (Pandion haliaetus) in flight carrying twig for nest, Vaala, Finland, June

Chris Gomersall / 2020VISION / Common starling (Sturnus vulgaris) adult with insect food arriving at nestbox to feed chicks, Hope Farm RSPB Reserve, Cambridgeshire, England, UK, May

Mark Hamblin / 2020VISION / Barn swallow (Hirundo rustica) collecting material for nest building, Scotland, UK, June

Mark Hamblin / 2020VISION / Barn swallow (Hirundo rustica) alighting at pond, collecting material for nest building, Scotland, UK, June. Did you know? Barn swallows will feed their nestlings up to 400 times every day.

Brent Stephenson / Male Australasian Gannet (Morus serrator) flying with seaweed for use as nesting material. Cape Kidnappers, Hawkes Bay, New Zealand, September.

John Cancalosi / Cattle Egret (Bubulcus ibis) standing with nesting material. Costa Rican tropical rainforest.

Mark Hamblin / 2020VISION / Hen harrier (Circus cyaneus) adult female diving to nest site, carrying nesting material, moorland habitat, Glen Tanar Estate, Grampian, Scotland, UK, June. Did you know? Although Hen harriers have be...

Patricio Robles Gil / Pale-legged Hornero (Furnarius leucopus) male and female birds building their mud nest on a branch. Parana, Southern Brazil.

David Tipling / 2020VISION / Marsh Harrier (Circus cyaneus) female in flight carrying nest material, Fens, East Anglia, UK, April

Diane McAllister / Great blue heron (Ardea herodias) landing with branch for its mate, who is constructing their nest on a treetop. Venice Rookery, Florida, USA, January