Dave Bevan / Pair of Sand martins (Riparia riparia) feeding chicks, Carmarthenshire, Wales, UK, July.

Pedro Narra / Barn Swallow (Hirundo rustica) in flight. Portugal, Europe

Dave Bevan / Swallow (Hirundo rustica) feeding juveniles perched on a rope near nest in a barn, Carmarthenshire, Wales, UK, September.

Dave Bevan / Pair of Swallows (Hirundo rustica) feeding chicks at nest in a barn, filmed using infra red, Carmarthenshire, Wales, UK, September.

Dave Bevan / Slow motion clip of a Swallow (Hirundo rustica) flying into a barn in heavy rain, Carmarthenshire, Wales, UK, September.

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

Bence Mate / Barn swallow (Hirundo rustica) mobbing Euasian Kestrel (Falco tinnunculus) Pusztaszer, Hungary, June.

Loic Poidevin / wo juvenile Barn swallows (Hirundo rustica)peched on a twig and begging for food, Indre-et-Loire , France, June.

Loic Poidevin / Barn swallow (Hirundo rustica) flying low over the ground, Indre-et-Loire , France, June.

Ernie Janes / Swallow (Hirundo rustica) adult perched on swallow weather vane, England, UK, June.

Ole Jorgen Liodden / Welcome Swallow (Hirundo neoxena) perched with shadow, Tasmania. December.

David Pattyn / Common tern (Sterna hirundo) catching a fish, action shot, Camargue, France, July

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

Mark Hamblin / 2020VISION / Barn Swallow (Hirundo rustica) alighting at pool to collect mud for nest building. Inverness-shire, Scotland, June .Did you know? Due to the distances that Swallows travel, it was traditional for sail...

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...

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.

Chris Gomersall / 2020VISION / Two Barn swallows (Hirundo rustica), Hertfordshire, England, UK, May

Markus Varesvuo / Barn swallow feeding chick on the wing (Hirundo rustica) Sipoo Finland July

Sven Zacek / Barn Swallow (Hirundo rustica) in flight. Estonia, Europe, June.

Loic Poidevin / Common Tern (Sterna hirundo) among nettles. Farne Isles, UK, June.

Loic Poidevin / Adult Common Tern (Sterna hirundo) hovering over its chicks, one of which has taken a small fish from the adult. Noirmoitier Island, French Atlantic Coast, July.

Ernie Janes / Barn swallow (Hirundo rustica) two young swallows on barn roof calling for food, Norfolk, UK, August

Edwin Giesbers / Common tern (Sterna hirundo) flying through grassland at dusk, Lesbos, Greece

Stephen Dalton / Barn swallow (Hirundo rustica) flying through gap in stable door, UK

Stephen Dalton / Barn swallow (Hirundo rustica) in flight, UK

Stephen Dalton / Swallow (Hirundo rustica) feeding chicks on nest build over light bulb, England, UK

Markus Varesvuo / Swallow (Hirundo rustica) flying low over water, Israel, March

Stephen Dalton / Barn swallow {Hirundo rustica} flying out of stable, UK

Stephen Dalton / Barn swallow (Hirundo rustica) drinking while in flight, UK

Stephen Dalton / Barn swallow (Hirundo rustica) drinking while in flight, UK

Wild Wonders of Europe / Lesniewski / Barn swallow (Hirundo rustica) in flight, Bagerova Steppe, Kerch Peninsula, Crimea, Ukraine, July 2009

Wild Wonders of Europe / Lesniewski / Barn swallow (Hirundo rustico) perching on reed, Bagerova Steppe, Kerch Peninsula, Crimea, Ukraine, July 2009

Wild Wonders of Europe / Lundgren / Common tern (Sterna hirundo) in flight, Pico, Azores, Portugal, June 2009

Wild Wonders of Europe / della Ferrera / House martin (Delichon urbicum) and a Swallow (Hirundo rustica) collecting mud to build nests, Neretva river delta, Dalmatia region, Croatia, May 2009

Andy Sands / Barn swallow (Hirundo rustica) adult flying into barn through derelict window, Hertfordshire, England, UK

Markus Varesvuo / Rock Martin (ptyonoprogne fuligula)in flight, Israel

Laurie Campbell / Silhouette of Barn Swallow (Hirundo rustica) flying over water, hawking for insects, Berwickshire, Scotland, UK, July

Alan Williams / Barn swallow (Hirundo rustica) in flight, Cheshire, UK, June

Wild Wonders of Europe / Peltomäki / Two Common terns (Sterna hirundo) one with fish in its beak, the other calling, Texel, Netherlands, May 2009

Andy Sands / Barn swallow (Hirundo rustica) in full song on dead Elm twig, Hertfordshire, England, UK.

Jose B. Ruiz / Barn swallow {Hirundo rustica} flying through barn window, Potes, Picos de Europa, Asturias, Spain

Graham Eaton / Female Barn swallow (Hirundo rustica) passing food to a sibling in flight, UK

Markus Varesvuo / Barn swallow (Hirundo rustica) chick on branch begging adult for food. Sipoo, Finland.

Kim Taylor / Barn swallow (Hirundo rustica) carrying drone honey bee prey (digitally enhanced) UK

Kim Taylor / Barn swallow (Hirundo rustica) group over the cliffs of southern England (digitally enhanced)

Tom Vezo / Common tern {Sterna hirundo} in flight, USA.

Kim Taylor / Barn swallow {Hirundo rustica} drinking on the wing. Digitally enhanced.