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

Marie Read / Eastern bluebird (Sialia sialis) male fluttering wings while perched on cherry (Prunus sp.) branch in spring, New York, USA, April.

Markus Varesvuo / Blue tit (Parus caeruleus) perched on tree trunk, looking at camera with wing stretched. Haukipudas, Finland. January.

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 / Blue-footed booby (Sula nebouxii) diving towards sea, folding wings. Northeast coast, Santiago Island, Galapagos. Sequence 1/2.

Tui De Roy / Blue-footed booby (Sula nebouxii) landing. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) coming in to land. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), five diving into sea. Espumilla Beach, Santiago Island, Galapagos.

Nick Garbutt / Red-and-green macaw (Ara chloropterus) flock flying in front of clay lick. Heath River, Tambopata / Bahuaja-Sonene Reserves, Amazonia, Peru / Bolivia border.

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

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...

Wim van den Heever / Red-and-green macaw (Ara chloropterus) in flight, Pantanal, Brazil. August.

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

Sven Zacek / White-tailed sea eagle (Haliaeetus albicilla) in flight, against a clear blue sky, Norway, July.

Sven Zacek / White-tailed sea eagle (Haliaeetus albicilla) flying, against a clear blue sky, Norway, July.

Ernie Janes / Fulmar (Fulmaris glacialis) in flight with Hunstanton, Norfolk, England, UK, February.

Espen Bergersen / Gyrfalcon (Falco rusticolus) and Raven (Corvus corax) in flight, Hornoya bird cliff, Finnmark, Norway. March

Espen Bergersen / Common guillemot (Uria aalge) flock, circling outside the breeding colony at Hornoya birdcliff, Finnmark, Norway.

Ole Jorgen Liodden / Eurasian eagle-owl (Bubo bubo) in flight, Norway, July.

Ole Jorgen Liodden / Arctic tern (Sterna paridisea) mobbing, Arctic fox (Alopex lagopus) in Spitsbergen, Svalbard, Norway, July.

Ole Jorgen Liodden / Arctic tern (Sterna Paradisaea) flying, Svalbard, Norway, July.

Tui De Roy / White-vented storm petrel (Oceanites gracilis galapagoensis) 'walking' on surface of water whilst foraging, Galapagos

Tui De Roy / Galapagos hawks (Buteo galapagoensis) in flight, Galapagos, Ecuador. Vulnerable species.

Markus Varesvuo / Red-crowned Crane (Grus japonensis) in flight, Hokkaido, Japan, February

Jack Dykinga / Snow geese (Anser caerulescens) flying toward their gathering pond, with moon in the background, Boque del Apache National Wildlife Refuge, New Mexico. December.

Sam Hobson / Peregrine falcons (Falco peregrinus), juvenile female and male in flight, fighting over prey. Bristol, UK. June.

Ross Hoddinott / Male banded demoiselle (Calopteryx splendens), resting on reed, Lower Tamar Lakes, Cornwall, UK. June.

Sam Hobson / Peregrine falcon (Falco peregrinus), adult male landing on building. Bristol, UK. March.

Bence Mate / Red and green macaws (Ara chloropterus) in flight, motion blurred photograph, Buraxo das aras, Brazil.

Robin Chittenden / Peregrine falcon (Falco peregrinus) flying past spire, Norwich Cathedral, Norfolk, UK, June.

Roger Powell / Pair of Montagu's harriers (Circus pygargus) undertaking a courtship food pass, Castro Verde, Alentejo, Portugal, April.

Ben Cranke,Ben Cranke / White naped cranes (Grus vipio) in flight, Kyushu, Japan

Paul Harcourt Davies / Newly emerged adult Two-tailed Pasha (Charaxes jasius) Podere Montecucco. Orvieto, Umbria, Italy August

Benjamin Barthelemy / Brown argus (Aricia agestis) butterfly, Vallee de la Seille (Seille Valley), Lorraine, France, August.

Michael Pitts,Michael Pitts / Sooty Terns (Onychoprion fuscata) flock in flight, Midway Island. Central Pacific.

Andy Sands / Kingfisher (Alcedo atthis) male preening wing with muddy bill, Hertfordshire, England, UK, March.

Andy Sands / Kingfisher (Alcedo atthis) male preening wing on mossy branch, Hertfordshire, England, UK, March

Guy Edwardes / Superb Starling (Lamprotornis superbus) with wing raised as a threat to nearby rival. Serengeti National Park, Tanzania, Africa, February

Ingo Arndt / Blue Morpho (Morpho peleides) butterfly wing with false eyespots, Costa Rica

Heidi & Hans-Juergen Koch / Blue Bottle Fly (Calliphora erythrocephala) flying, worldwide distribution

Rolf Nussbaumer / Close up of wing feathers of Blue jay {Cyanocitta cristata} Texas, USA.

Michael & Patricia Fogden / Violet-crowned Woodnymph (Thalurania colombica) hummingbird male perched in lowland rainforest, Costa Rica

John Cancalosi / White-winged dove (Zenaida asiatica) vocalising, perched on Sotol (Dasylirion wheeleri). Sonoran desert , Arizona, USA. July.

Hanne & Jens Eriksen / Swainson's hawk (Buteo swainsoni) in flight. Saskatchewan, Canada, August.

Loic Poidevin / Lapped-faced Vulture (Torgos tracheliotos) in flight, Masai Mara, Kenya. March.

Claudio Contreras / California condor (Gymnogyps californianus) in flight, wings radio tagged. California condor recovery program, Sierra de San Pedro Martir National Park, Baja California Peninsula, Mexico. 2011.

Claudio Contreras / California condor (Gymnogyps californianus) in flight, wings radio tagged. California condor recovery program, Sierra de San Pedro Martir National Park, Baja California Peninsula, Mexico. 2011.

Claudio Contreras / California condor (Gymnogyps californianus) juvenile in flight, wings radio tagged. California condor recovery program in Mexico, Sierra de San Pedro Martir National Park, Baja California Peninsula, M...

Steven David Miller / Little red flying fox (Pteropus scapulatus) female and suckling baby in flight, searching for place to roost. Nitmiluk National Park, Northern Territory, Australia.

Andy Rouse / Indian peafowl (Pavo cristatus) male flying over water. Ranthambhore National Park, India.

Steven David Miller / Galah (Eolophus roseicapillus) juvenile perched on branch with wings spread, moon in background. Mary River National Park, Northern Territory, Australia.

Robin Chittenden / Common buzzard (Buteo buteo) in flight, view from below. Norfolk, England, UK. March.

John Chan / Great blue heron (Ardea herodias) stretching its wings at dusk, Southern California, USA, July.

George Sanker / Great blue heron (Ardea herodias) landing with wings outstretched at water's edge. Myakka River State Park, Florida, USA, March.

George Sanker / Great blue heron (Ardea herodias) in flight, landing. Myakka River State Park, Florida, USA. February.

George Sanker / Great blue heron (Ardea herodias) with wings outstretched. Myakka River State Park, Florida, USA. February.

George Sanker / Great blue heron (Ardea herodias) in flight. Myakka River State Park, Florida, USA. February.

George Sanker / Great blue heron (Ardea herodias) in flight. Myakka River State Park, Florida, USA. February.

George Sanker / Great blue heron (Ardea herodias) flying with fish in beak. Everglades National Park, Florida, USA. March.

George Sanker / Great blue heron (Ardea herodias) landing in water. Myakka River State Park, Florida, USA. February.

George Sanker / Great blue heron (Ardea herodias), wings spread. Myakka River State Park, Florida, USA. February.

George Sanker / Purple gallinule (Porphyrio martinicus) striding over Lily (Nymphaeaceae) pads. Everglades National Park, Florida, USA. March.

George Sanker / Great blue heron (Ardea herodias) taking off from water. Everglades National Park, Florida, USA. March.

Steven David Miller / Brahminy Kite (Haliastur indus) flying high, Ballina, Queensland Australia. October.

Steven David Miller / A Common eggfly butterfly (Hypolimnas bolina) at rest, Cairns Botanical Gardens, Queensland, Australia. Captive.

Marie Read / Roseate spoonbill (Ajaia ajaja), adult in breeding plumage flying in to land on a perch, Orlando, Florida, USA, March.

Marie Read / Snowy Egret (Egretta thula) adult in breeding plumage taking flight, Viera Wetlands, Florida, USA, March.

Marie Read / Cinnamon teal (Anas cyanoptera), male taking flight from water, Orange County, California, USA, April.

Marie Read / Northern gannets (Morus bassanus) performing sky-pointing display with outspread wings as part of courtship, Cape St. Mary's Ecological Reserve, Newfoundland, Canada. June.

Markus Varesvuo / White-fronted goose (Anser albifrons) in flight, viewed from below. Latvia. April.

Markus Varesvuo / Peregrine (Falco peregrinus) flying against blue sky, Vaala Finland July 2017

Markus Varesvuo / Blue tit (Parus caeruleus) perched on tree trunk, looking at camera. Haukipudas, Finland. January.

David Tipling / Eurasian sparrowhawk (Accipiter nisus) female in flight. Norfolk, England, UK. October.

Pal Hermansen / Black-legged kittiwake (Rissa tridactyla), two fighting in mid-air. Above nesting cliff, Hornoya, Finnmark, Norway. March.

Staffan Widstrand / Wild Wonders of China / Hill Pigeon or Eastern Rock Dove (Columba rupestris) in flight, bird breeding at the Taoist Tian Feng Ling Temple, Beiyue Hengshan Mountain, Datong, Hunyuan County, Shanxi Province, China

Tui De Roy / Flightless cormorant (Phalacrocorax harrisi) on rocks with nesting material in beak. Cape Douglas, Fernandina Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) diving into sea, wings outstretched. Cerro Brujo, San Cristobal island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), chick looking upwards with wings stretched. Santa Cruz Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), five flying, folding wings to dive into water. Cape Douglas, Fernandina Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) in flight. Espumilla Beach, Santiago Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), three flying downwards. Espumilla Beach, Santiago Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), six diving into sea. Espumilla Beach, Santiago Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) diving towards sea, wings folded. Northeast coast, Santiago Island, Galapagos. Sequence 2/2.

Tui De Roy / Blue-footed booby (Sula nebouxii) landing. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) landing amongst others in colony. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), adult with begging chick. Punta Vicente Roca, Isabela Island, Galapagos

Tui De Roy / Blue-footed booby (Sula nebouxii), adult with begging chick. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) landing. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) landing. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii) landing with feet up. Punta Vicente Roca, Isabela Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), chick holding wings aloft with adult behind. Punta Pitt, San Cristobal Island, Galapagos. April 2017.

Tui De Roy / Blue-footed booby (Sula nebouxii) folding wings as it dives towards sea. Cerro Brujo, San Cristobal Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), four diving towards sea. Espumilla Beach, Santiago Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), four diving towards sea. Espumilla Beach, Santiago Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), four beginning dive towards sea. Espumilla Beach, Santiago Island, Galapagos.

Tui De Roy / Blue-footed booby (Sula nebouxii), three diving towards sea. Espumilla Beach, Santiago Island, Galapagos.