Solvin Zankl / After an incubation period of 45 to 55 days and several days long ascent through the sand the hatchling Olive ridley turtles (Lepidochelys olivacea) emerge all together. Ostional Beach, Costa Rica, No...

Pete Oxford / Waved albatross (Phoebastria irrorata) pair at nest after change over for incubation, Punta Suarez, Española Island, Galapagos Islands

Fred Bavendam / Australian Giant Cuttlefish (Sepia apama) hatchling swimming past the egg of an unhatched sibling after an incubation of about four months, southern Australia

Fred Bavendam / Horseshoe Crab (Limulus polyphemus) eggs almost ready to hatch after two weeks incubation in the warm sands of Cape Anne, Massachusetts

WILLIAM OSBORN / Canada goose sitting on eggs at nest {Branta canadensis} Wiltshire England UK

Paul Hobson / Red throated diver (Gavia stellata) incubating eggs on nest, Iceland June

Paul Hobson / Red throated diver (Gavia stellata) incubating eggs on nest, Iceland June

Paul Hobson / Avocet (Recurvirostra avosetta) at nest with eggs, Texel, Holland, May

Marie Read / Pileated Woodpeckers (Dryocopus pileatus), pair during incubation exchange, female clinging to treetrunk as male comes out of nest hole entrance, spring, New York, USA, May.

Yukihiro Fukuda / Phoenix Petrel (Pterodroma alba) incubating; this species lays their eggs directly on the ground. Christmas Island, July

Roger Powell / Stone curlew (Burhinus oedicnemus) pair changing over incubation duties at the nest, Guerreiro, Castro Verde, Alentejo, Portugal, April

Tui De Roy / Red-footed booby (Sula sula) incubating single egg with webbed feet. Darwin Bay, Genovesa (Tower) Island, Galapagos, Ecuador, June.

Tui De Roy / Waved albatross (Phoebastria irrorata) incubating egg with specialised ventral plumage. Punta Cevallos, Espanola (Hood) Island, Galapagos, Ecuador, May.

Nick Upton / 2020VISION / Nigel Jarrett, Aviculture manager, inspects developing Common / Eurasian crane eggs (Grus grus) in an egg-turning incubator, WWT Slimbridge, Gloucestershire, England, UK, May 2009. 2020VISION Exhibiti...

Roland Seitre / Breeding project of the Hermit / Northern bald ibis (Geroniticus eremita) at the Jerez de la Frontera Zoo, Cadiz, Spain. Two eggs in tray. Critically endangered species. June 2007

Brent Stephenson / Adelie Penguin (Pygoscelis adeliae) lying down on its stone nest incubating its eggs. Yalour Islands, Antarctic Peninsula, Antarctica, December.

Konrad Wothe / Brown Honeyeater (Lichmera indistincta) male in nest, Queensland, Australia, October

Kevin Schafer / Maleo (Macrocephalon maleo) digging nest hole in hot sand for natural incubation, Sulawesi, Indonesia, Endangered

Kevin Schafer / Maleo (Macrocephalon maleo) digging hole in hot sand for natural incubation, Sulawesi, Indonesia, Endangered

Terry Whittaker / 2020VISION / Volunteer Warden, Ray Sykes, using night vision optics to observe the Manton Bay osprey pair at night, Rutland Water, Rutland, UK, April 2011. During the incubation period the Osprey nest is observed...

Solvin Zankl / After an incubation period of 45 to 55 days and several days long ascent through the sand the hatchling Olive ridley sea turtles (Lepidochelys olivacea) emerge from the nest all together. Ostional be...

Solvin Zankl / After an incubation period of 45 to 55 days and several days long ascent through the sand the hatchling Olive ridley sea turtles (Lepidochelys olivacea) emerge from the nest all together. Ostional bea...

Solvin Zankl / After an incubation period of 45 to 55 days and several days long ascent through the sand a hatchling Olive ridley sea turtle (Lepidochelys olivacea) emerges from the nest. Ostional Beach, Costa Rica,...

LYNN M. STONE / Greater Sandhill Crane (Grus canadensis tabida) rolling two eggs for even incubation on mounded nest of reeds in wetland, southern Wisconsin, USA

Nick Upton / 2020VISION / Nigel Jarrett, Aviculture manager, inspects developing Common / Eurasian crane eggs (Grus grus) in an egg-turning incubator, WWT Slimbridge, Gloucestershire, UK, May 2009. 2020VISION Book Plate.

David Woodfall / Little terns (Sternula albifrons) pair changing over incubation at nest, Northumberland, UK

Tui De Roy / Rockhopper Penguin (Eudyptes chrysocome) pair exchanging incubation duties, New Island, Falkland Islands

Jeff Rotman / Wildlife biologist removing eggs from Pink Salmon (Oncorhynchus gorbuscha) in preparation for incubation. Quinsam Salmon Hatchery, British Coloumbia, Canada, September 2008

Pete Oxford / Waved albatross (Phoebastria irrorata) pair at nest, change over for egg incubation, Punta Cevallos, Española Island, Galapagos Islands

Pete Oxford / Waved albatross (Phoebastria irrorata) pair at nest after change over for incubation, Punta Suarez, Española Island, Galapagos Islands

Pete Oxford / Waved albatross (Phoebastria irrorata) pair at nest after change over for incubation, Punta Suarez, Española Island, Galapagos Islands

Tim Laman / Philippine Eagle Center director, Domingo Tadena, turns and weighs a precious Philippine eagle egg {Pithecophaga jefferyi} being incubated at the center, Mindanao Island, Philippines, November 2001.

Gary K. Smith / Baby chickens {Gallus gallus domesticus} under heat lamp, Norfolk, UK, May

Fred Bavendam / Saddleback Anemonefish (Amphiprion polymnus) eggs on their fourth day of incubation, Bali, Indonesia

Fred Bavendam / Saddleback Anemonefish (Amphiprion polymnus) eggs on their fourth day of incubation, Bali, Indonesia

WILLIAM OSBORN / Ostrich {Struthio camelus} turning / candling eggs in incubator, Queensland, Australia

Doug Allan / King Penguin egg being held off ground by feet {Aptenodytes patagoni}, South Georgia

Igor Shpilenok / White storks {Ciconia ciconia} place manure in nest to incubate eggs, Russia. Bryanksy

GEORGETTE DOUWMA / Jawfish {Opistognathus sp} male with eyed brood of eggs in mouth, Borneo

Jane Burton / Domestic hen's egg {Gallus gallus domesticus} , showing embyro after 72 hours, UK.

Gerry Ellis / Green Sea Turtle (Chelonia mydas) egg incubation station, Turtle Island, Borneo

Gerry Ellis / Green Sea Turtle (Chelonia mydas) eggs being retrieved by ranger in preparation for incubation, South Pacific

Tui De Roy / Great Frigatebird (Fregata minor) female laying egg with male waiting to take over first incubation stint, Genovesa Tower Island, Galapagos Islands, Ecuador

Tui De Roy / Southern Royal Albatross (Diomedea epomophora) pair changing over duties during 70 day incubation, Mt Lyall Ridge, Campbell Island, New Zealand

Tui De Roy / Southern Royal Albatross (Diomedea epomophora) sitting on single egg during 77-81 day incubation, Lyall Ridge, Campbell Island, New Zealand

Tui De Roy / North Island Brown Kiwi (Apteryx australis mantelli) newly-hatched chick still carrying a large yolk reserve after 70 days of incubation, Kiwi House, Otorohanga Breeding Facility, New Zealand

Tui De Roy / Galapagos Rail (Laterallus spilonotus) pair sharing incubation duties on nest in grass along edge of scalesia forest highlands, Santa Cruz Island, Galapagos Islands, Ecuador

Tui De Roy / Buller's Albatross (Thalassarche bulleri) endemic to New Zealand's southern islands, pair swapping duties during 69 day incubation, Snares Islands, New Zealand

Tui De Roy / Buller's Albatross (Thalassarche bulleri) endemic to New Zealand's southern islands, pair reinforcing their mud nest during incubation swap, Snares Islands, New Zealand

Tui De Roy / Buller's Albatross (Thalassarche bulleri) endemic to New Zealand's southern islands, pair sharing duties during 69 day incubation, Snares Islands, New Zealand

SIMON KING / Cory's shearwater on nest {Calonectris diomedea} Azores, Atlantic ocean

SIMON KING / Cory's shearwater on nest {Calonectris diomedea} Azores, Atlantic ocean

Gabriel Rojo / Silvery grebe on nest with eggs {Podiceps occipitalis} La Pampa, Argentina

Doug Allan / King penguin carrying egg on feet to keep it warm, South Georgia, Antarctic

Nick Barwick / Lapwing chick starts to break out of egg {Vanellus vanellus} Mid Yare RSPB Reserve Norfolk UK. After 26-28 days of incubation egg tooth can be seen.

WILLIAM OSBORN / Brush turkey male tests incubation temperature in nest mound {Alectura lathami}. SE Queensland, Australia Male uses beak to test temperature and then adds or removes soil to regulature temperature

Gabriel Rojo / Silvery grebe on nest {Podiceps occipitalis} La Pampa, Argentina Macachin

Gabriel Rojo / Silvery grebe on nest {Podiceps occipitalis} La Pampa, Argentina Atreu-co

Gabriel Rojo / Silvery grebe on nest with eggs {Podiceps occipitalis} La Pampa, Argentina Atreu-co

Juergen Freund / Incubator with Hermanns tortoise eggs Breeding station Italy {Testudo hermanni}