Ismaele Tortella / Northern gannet (Morus bassanus) colony, chick climbing back into nest, with the midnight sun, Norway, July

Ismaele Tortella / Black-legged kittiwake (Rissa tridactyla) nesting above a window, Lofoten, Norway, August.

Winfried Wisniewski / White Stork (Ciconia ciconia) on nest, Extremadura, Spain

Martin Willis / Budgerigar (Melopsittacus undulatus) father with begging chick at nest cavity, Queensland, Australia

Danny Green / Brunnich's guillemot (Uria lomvia) colony in mist, many birds in flight and nesting on cliffs. Svalbard, Norway, July 2018.

Phil Savoie / Blue tit (Cyanistes caeruleus) bringing Crab spider (Misumena vatia) prey to nest, Monmouthshire Wales, UK, May.

David Woodfall / Hedge which has been 'netted ' to prevent breeding birds nesting, which would delay building development of new homes. The tree in the background has also been cut back. Chester, Cheshire, Eng...

Terry Whittaker / Man collecting seabird eggs, including those of Common guillemots (Uria aalge), Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being lowered down a cliff to collect seabird eggs, including those of Common guillemots (Uria aalge). Camera attached to helmet, Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being lowered down cliff to collect seabird eggs, including those of Common guillemots (Uria aalge), Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being raised up cliff to collect seabird eggs, including those of Common guillemots (Uria aalge), Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being lowered down a cliff to collect seabird eggs, including those of Common guillemots (Uria aalge). Camera attached to helmet, Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being lowered down a cliff to collect seabird eggs, including those of Common guillemots (Uria aalge). Camera attached to helmet, Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being lowered down a cliff to collect seabird eggs, including those of Common guillemots (Uria aalge). Camera attached to helmet, Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

Terry Whittaker / Man being lowered down a cliff to collect seabird eggs, including those of Common guillemots (Uria aalge). Skoruvikurbjarg cliffs, Langanes Peninsula, Iceland, May.

John Chan / Great horned owl (Bubo virginianus) chicks stretching and flapping their wings, Southern California, USA, May.

David Woodfall / Little tern (Sterna albifrons) nest with three eggs in shingle ridge. County Wicklow, Republic of Ireland, June.

David Woodfall / Two Little terns (Sterna albifrons) at the nest amongst Black oats (Avena strigosa) growing on shell rich sands Machair, North Uist, Scotland, UK, June.

David Woodfall / Little tern (Sterna albifrons) at the nest amongst Black oats (Avena strigosa) growing on shell rich sands Machair, North Uist, Scotland, UK, June.

David Woodfall / Little tern (Sterna albifrons ) feeding sand eel (Hyperoplus spp) to young chick. Gronant Dunes, Denbighshire, Wales, UK, June.

John Shaw / Common eider duck (Somateria mollissima) female defending her nest from arctic fox (Vulpes lagopus). Longyearbyen, Spitsbergen. June.

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

John Shaw / Roseate spoonbill (Platalea ajaja) at its nesting colony site, in early morning light. St. Johns Management Area, Florida, USA, April.

John Cancalosi / Great horned owl (Bubo virginianus) chick stretching its wings in nest in a Saguaro (Carnegiea gigantea), is groomed by its parent, Sonoran Desert, Arizona, USA, May.

John Chan / Anna's Hummingbird (Calypte anna) chick, sleeping in nest, Southern California, USA, March.

SCOTLAND: The Big Picture / Golden eagle (Aquila chrysaetos) adult with nest material on eyrie with chick showing background, Isle of Lewis, Scotland, UK., May.

Steven David Miller / Olive-backed sunbird (Nectarinia jugularis) female returning to her nest with nesting material, Cape Hillsborough National Park, Queensland, Australia, September.

Steven David Miller / Olive-backed Sunbird (Nectarinia jugularis) female in her nest, Cape Hillsborough National Park, Queensland, Australia, September.

Stefan Christmann / Adelie penguin (Pygoscelis adeliae) nesting pair, Atka Bay, Queen Maud Land, Antarctica, December.

David Gallan / Slow motion clip of a Wedge-tailed eagle (Aquila audax) landing in nest, Mimosa National Park, New South Wales, Australia , September.

John Chan / Female Anna's hummingbird (Calypte anna) incubating eggs, departs from nest momentarily to feed, Southern California, USA, March.

John Chan / Female Anna's hummingbird (Calypte anna) incubating eggs, departs from nest momentarily to feed, Southern California, USA, March.

Karine Aigner / Fernandina's flicker (Colaptes fernandinae) peering out of nest hole, Cuba

Karine Aigner / Cuban bare-legged owl (Margarobyas lawrencii) in nest hole. Cienaga de Zapata, Cuba.

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...

John Chan / Juvenile California least tern (Sternula antillarum browni) begging for food from a decoy, used to attract breeding pairs to deserted nest sites, Huntington Beach, California, USA, June.

John Chan / California least tern chick (Sternula antillarum browni) falling over as it runs towards its parent returning to nest site, Huntington Beach, California, USA, June.

Nick Upton / White stork (Ciconia ciconia) parent standing beside its three developing chicks. In captive breeding colony raising young birds for UK White Stork reintroduction project at the Knepp Estate. Cotswold...

Nick Upton / White stork (Ciconia ciconia) nest at captive breeding colony raising chicks for UK White Stork reintroduction project at the Knepp Estate. Cotswold Wildlife Park, Oxfordshire, UK, May 2019.

Nick Upton / Richard Wardle feeding fish to recently hatched White stork (Ciconia ciconia) chicks in nest. In captive breeding colony raising young birds for UK White Stork reintroduction project at the Knepp Esta...

Nick Upton / Recently hatched White stork (Ciconia ciconia) chicks begging for food in their nest. In captive breeding colony raising young birds for UK White Stork reintroduction project at the Knepp Estate. Cots...

John Chan / Great blue heron (Ardea herodias) chick begging to be fed, Southern California, USA, April.

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 and nestling on nest in tree stump. Tartumaa, Southern Estonia. May.

Sven Zacek / Ural owl (Strix uralensis) female on nest after snowfall. Tartumaa, Southern Estonia. March.

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.

Sven Zacek / Ural owl (Strix uralensis) female in flight having taken off from nest, in evening light. Tartumaa, Southern Estonia. May.

Sven Zacek / Ural owl (Strix uralensis) female flying with prey in beak. Flying back to nest in evening light. Tartumaa, Southern Estonia. May.

Pedro Narra / White spoonbill (Platalea leucorodia) adults at nest with chicks, Sado estuary, Portugal. May

Pedro Narra / Barn Owl (Tyto alba) chicks in nest, Sado Estuary, Portugal . June

Oscar Dewhurst / Black-legged kittiwake (Rissa tridactyla) adults and chicks on nests on the Tyne Bridge. Newcastle, UK. July.

Brian Bevan / Male Green woodpecker (Picus viridis) feeding young at nest hole, shot looking up trunk, Bedfordshire, England, UK, June.

Brian Bevan / Juvenile Green woodpecker (Picus viridis) leaving nest hole, shot looking up trunk, Bedfordshire, England, UK, June.

Brian Bevan / Male Green woodpecker (Picus viridis) feeding young at nest hole, shot looking up trunk, Bedfordshire, England, UK, June.

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

Brian Bevan / Slow motion clip of a male Kingfisher (Alcedo atthis) taking fish into nest hole before exiting backwards, Bedfordshire, England, UK, July.

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 / 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 / Northern gannets (Morus bassanus) in breeding colony, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, May.

Philippe Clement / Northern gannets (Morus bassanus) sitting on nests made with plastic, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, May.

Philippe Clement / Northern gannets (Morus bassanus) preening, sitting on nests made with plastic, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, May.

Philippe Clement / Northern gannets (Morus bassanus) preening at breeding colony, Hermaness NNR, Unst, Shetland Islands, Scotland, UK, May.

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

Dave Bevan / Pair of Sand martins (Riparia riparia) feeding chicks, 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.

Dave Bevan / Slow motion clip of a pair of Common swifts (Apus apus) approaching and entering a nest hole in limestone cliff, Norfolk, England, UK, May.

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

David Perpinan / Blue-fronted amazon parrot (Amazona aestiva) entering nest in tree, Pantanal, Mato Grosso do Sul, Brazil.

David Perpinan / Great rufous woodcreeper (Xiphocolaptes major) arriving at nest site in a dead palm tree, climbs down to nest, Pantanal, Mato Grosso do Sul, Brazil.

David Perpinan / Rhea (Rhea americana) incubating eggs, gets up and turns one over, Pantanal, Mato Grosso do Sul, Brazil.

David Perpinan / Common rock sparrow (Petronia petronia) feeding chicks in nest, filmed using an infra-red camera, Cuenca, Castile-La Mancha, Spain, June.

David Perpinan / Common rock sparrow (Petronia petronia) chick exploring outside nest, Cuenca, Castile-La Mancha, Spain, June.

David Perpinan / Adult Common rock sparrow (Petronia petronia) feeding chicks, Cuenca, Castile-La Mancha, Spain, June.

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

David Perpinan / Oystercatcher (Haematopus ostralegus) incubating eggs on nest, alarm calling as a predator flies overhead, Scotland,UK, June.

David Perpinan / Rock sparrow (Petronia petronia) feeding chick outside nest, Spain, June.

Bence Mate / European roller (Coracias garrulus) peering out of nest with feather, Lake Csaj, Pusztaszer, Kiskunsagi National Park, Hungary, February.

Michael Quinton / Northern Hawk Owl (Surnia ulula) pair at nest, Alaska

Michael Quinton / Northern Hawk Owl (Surnia ulula) peering from nest, Alaska

Michael Quinton / Northern Hawk Owl (Surnia ulula) parent with chicks at nest, Alaska

Dave Bevan / Male Great spotted woodpecker (Dendrocopos major) flying to a nest hole in an electricty pole and feeding chick, Carmarthenshire, Wales, UK, June.

Dave Bevan / Common raven (Corvus corax) flying to nest to feed fledglings, Carmarthenshire, Wales, UK, May.

Dave Bevan / Slow motion clip of two pairs of Jackdaws (Corvus monedula) squabbling over nest site, Worcestershire, England, UK, May.

Dave Bevan / Slow motion clip of a Robin (Erithacus rubecula) flying to nest and feeding chicks, removes faecal sac, Carmarthenshire, Wales, UK, May.

Guy Edwardes / Reed cormorant (Microcarbo africanus) perched on termite mound, Khwai, Botswana.