Ismaele Tortella / Tracking shot of a Whooper swan (Cygnus cygnus) family walking, Lofoten, northern Norway, August.

Oscar Dewhurst / Mute swan (Cygnus olor), two cygnets sheltering under parent's wing. Richmond Park, London, England, UK. April.

Oscar Dewhurst / Mute swan (Cygnus olor) swimming with cygnets in misty lake in morning light. Richmond Park, London, England, UK. May.

Jack Dykinga / Sandhill cranes (Antigone canadensis) and Snow geese (Chen caerulescens) at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico, USA, November.

Jack Dykinga / Bald eagle (Haliaeetus leucocephalus) perched as Snow geese (Chen caerulescens) fly by, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

Jack Dykinga / Snow goose (Chen caerulescens) landing into a tight packed flock on lake, Bosque del Apache National Wildlife Refuge, New Mexico, USA. January.

Jack Dykinga / Snow goose (Chen caerulescens) landing into flock, Bosque del Apache National Wildlife Refuge, New Mexico, USA, January.

Ernie Janes / Brent geese (Branta bernicla) flying with moon, Titchwell, Norfolk, UK, December

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

Jack Dykinga / Flocks of Mallard ducks (Anas platyrhynchos) taking off in tree-lined wetlands. Bosque del Apache National Wildlife Refuge, New Mexico, USA.

Terry Whittaker / Mandarin duck (Aix galericulata) male female pair, Reddish Vale Country Park, Greater Manchester, UK. December

Marie Read / Wood Ducks (Aix sponsa), females behave aggressively toward a male (second from right) that is trying to join them on a floating log, autumn, New York, USA, October.

Marie Read / Canada geese (Branta canadensis) two during territorial fight in early spring, Ithaca. New York, USA

David Pattyn / Mute swan (cygnus olor) family, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June

Ernie Janes / RF - Mute swans (Cygnus olor) flock of non breeding adults, Fleet lagoon Dorset, England, UK, June. (This image may be licensed either as rights managed or royalty free.)

Russell Cooper / Mandarin duck drake (Aix galericulata) on the water, showing orange 'sail' feathers which are used when displaying, Southwest London, UK, March.

Russell Cooper / Mandarin duck drake (Aix galericulata) from behind flapping its wings. Southwest London, UK. February.

Markus Varesvuo / White-fronted goose (Anser albifrons) and Taiga bean goose (Anser fabalis rossicus) flocks in flight and on water. Latvia. April.

Donald M. Jones / Northern Pintail (Anas acuta) males flying with female in spring courtship display, Montana

Donald M. Jones / Mallard (Anas platyrhynchos) drake flying, Montana

Marion Vollborn/ BIA / Whooper Swan (Cygnus cygnus) group taking flight on snow, Hokkaido, Japan

David Tipling / Pink-footed geese (Anser brachyrhynchus) flying against strong northerly wind off Salthouse North Norfolk, wind turbines in sea in background, England, UK. November

David Allemand / Two Snow geese (Anser caerulescens) during migration, with dark clouds against the sun, Quebec, Canada, October.

Suzi Eszterhas / Mallard (Anas platyrhynchos) rehabilitator, Isabel Luevano, with one day old orphan duckling, International Bird Rescue, Fairfield, California

John Waters / Slow motion clip of a Mallard (Anas platyrhynchos) duckling chasing and catching Mayfly (Ephemeroptera) emerging from River Kennet, Hungerford, Berkshire, England, UK, June.

Konrad Wothe / Goosander (Mergus merganser) chick hunting mayfly, Upper Bavaria, Germany

John Waters / Male Shoveler (Anas clypeata) chasing other males away from his mate, Greyale RSPB Reserve, Somerset Levels, England, UK, February.

John Waters / Slow motion clip of a mixed flock of Teal (Anas crecca) and Wigeon (Anas penelope) landing in a lake, Greylake RSPB Reserve, Somerset Levels, England, UK, February.

Alfred Trunk/ BIA / Common Merganser (Mergus merganser) mother carrying chick, Upper Austria, Austria

Andrew Parkinson / Mute swan (Cygnus olor) cygnets with head submerged while feeding underwater, with mother watching and helping, Derbyshire, England, UK. June. Highly Commended in the Animal Behaviour category of the...

George Sanker / Mallard (Anas platyrhynchos) pair greeting on snow-covered pond. Acadia National Park, Maine, USA.

George Sanker / Mallard (Anas platyrhynchos)pair greeting on snow-covered pond. Acadia National Park, Maine, USA.

John Waters / Mixed flock of Wigeon (Anas penelope) and Northern lapwings (Vanellus vanellus) disturbed by hunting Marsh Harrier (Circus aeruginosus), Greylake RSPB Reserve, Somerset Levels, England, UK, December.

John Waters / Slow motion clip of a Wigeon (Anas penelope) preening, Catcott Lows Nature Reserve, Somerset Levels, England, UK, December.

Konrad Wothe / Common Merganser (Mergus merganser) mother with chicks, Upper Bavaria, Germany

Cyril Ruoso / Mute swan (Cygnus olor) feeding underwater, Burgundy, France, March.

Cyril Ruoso / Mute swan (Cygnus olor) feeding underwater, Burgundy, France, March.

Cyril Ruoso / Mute swan (Cygnus olor) feeding underwater, Burgundy, France, November.

Cyril Ruoso / Mute swan (Cygnus olor) feeding along riverbed, viewed underwater, Burgundy, France. November.

Cyril Ruoso / Mute swan (Cygnus olor) feeding along riverbed, viewed underwater, Burgundy, France. November.

Cyril Ruoso / Mute swan (Cygnus olor) feeding along riverbed, viewed underwater, Burgundy, France. November.

Andy Rouse / Mute swan (Cygnus olor) feeding at dawn, Cardiff, Wales, UK, March.

Steve Downer / Close up of a Canada goose gosling (Branta canadensis) sleeping, with other goslings in the background, Birmingham, England, UK, June.

SCOTLAND: The Big Picture / Panning shot of a large flock of Pink-footed geese (Anser brachyrhynchus) taking off from their roosting site, Montrose, Angus, Scotland, UK, November.

David Pattyn / Tufted duck (Aytha fuligula) female portrait.The Netherlands. April..

John & Mary-Lou Aitchison / Flock of Barnacle geese (Branta leucopsis) flying over the sea, Islay, Inner Hebrides, Scotland, UK, November.

Nick Upton / Panning shot of partially flooded pastureland with large flocks of Wigeon (Anas penelope), Lapwings (Vanellus vanellus) and Golden plover (Pluvialis apricaria) in flight, Gloucestershire, England, UK,...

Nick Upton / Panning shot of a flock of Lapwings (Vanellus vanellus) landing on partially flooded pastureland near resting Black-tailed godwits (Limosa limosa) and grazing Wigeon (Anas penelope), Gloucestershire,...

Willi Rolfes/ BIA / Greylag Goose (Anser anser) chick, Lower Saxony, Germany

Willi Rolfes/ BIA / Greylag Goose (Anser anser) chick, Lower Saxony, Germany

Marcos Baumann/ BIA / Speckled Teal (Anas flavirostris) flying, Valparaiso, Chile

Hans Glader/ BIA / White-fronted Goose (Anser albifrons) group flying, North Rhine-Westphalia, Germany

Nick Saunders/ BIA / Ruddy Duck (Oxyura jamaicensis) male in courtship display, Saskatchewan, Canada

Ann & Steve Toon / Egyptian goose (Alopochen aegyptiaca) with goslings, Zimanga private game reserve, KwaZulu-Natal, South Africa, September

Jack Dykinga / Snow geese (Chen caerulescens) large flock with some landing, Bosque del Apache, New Mexico, USA, December.

Jack Dykinga / Snow geese (Chen caerulescens) in flight in front of super moon, Bosque del Apache National Wildlife Refuge, New Mexico, USA, December.

Jack Dykinga / Sandhill cranes (Grus canadensis) and Snow geese (Chen caerulescens) Bosque del Apache National Wildlife Refuge, New Mexico, USA, December.

Tim Fitzharris / Snow Goose (Chen caerulescens) flock in pond at sunrise, Bosque del Apache National Wildlife Refuge, New Mexico

Jussi Murtosaari / Whooper swan (Cygnus cygnus) pair in flight in snowy landscape, Finland, November.

Thomas Hinsche/ BIA / Common Goldeneye (Bucephala clangula) male flapping, Saxony-Anhalt, Germany

Pal Hermansen / Barnacle geese (Branta leucopsis) with goslings, swimming past icebergs, Jokulsarlon, Iceland, June.

Andy Rouse / Mute swan (Cygnus olor) stretching in morning light, UK, February.

Pal Hermansen / Barnacle geese (Branta leucopsis) with goslings, Jokulsarlon ice field, Iceland, June.

Pal Hermansen / Eider ducks (Somateria molissima) flock taking off from sea, Trondelag, Norway, January.

Wim van den Heever / Egytian Goose (Alopochen aegyptiaca) rear view bathing, sings spread, Zimanga Private Game Reserves, South Africa

Bence Mate / Graylag gosling (Anser anser) resting under parent's wing, Pusztaszer, Kiskunsagi National Park, Pusztaszer, Hungary.

Bence Mate / Graylag gosling (Anser anser) resting under parent's wing, Kiskunsagi National Park, Pusztaszer, Hungary.

Bence Mate / Graylag gosling (Anser anser) with parent, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. April.

Bence Mate / Flock of Mallard ducks (Anas platyrhynchos) taking off, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. December.

Matthias Breiter / Snow Goose (Chen caerulescens) flock flying over coastal flats, Hudson Bay, Manitoba, Canada

Matthias Breiter / Snow Goose (Chen caerulescens) flock at coastal flats, Hudson Bay, Manitoba, Canada

Tim Fitzharris / Trumpeter Swan (Cygnus buccinator) flock flying, Arkansas

Wim van den Heever / Whooper swan (Cygnus cygnus) mid flight over the frozen lake, Kussharo, Hokkaido, Japan.

Wim van den Heever / Whooper swan (Cygnus cygnus) portrait, on frozen lake Kussharo, Hokkaido Japan, February.

Wim van den Heever / Whooper swans (Cygnus cygnus) juvenile with adults behind, on frozen Lake Kussharo, Hokkaido, Japan. February.

Donald M. Jones / Wood Duck (Aix sponsa) drake flying, central Montana

Donald M. Jones / Wood Duck (Aix sponsa) drake stretching wings, central Montana

Donald M. Jones / Trumpeter Swan (Cygnus buccinator) trio flying, southern Alaska

Donald M. Jones / Snow Goose (Chen caerulescens) group flying, central Montana

Donald M. Jones / Snow Goose (Chen caerulescens) landing in field, central Montana

Donald M. Jones / Northern Pintail (Anas acuta) drake flying, central Montana

Donald M. Jones / Mallard (Anas platyrhynchos) drake flying, central Montana

Donald M. Jones / Mallard (Anas platyrhynchos) hen, central Montana

Donald M. Jones / American Wigeon (Anas americana) drake, western Montana

Gerrit Vyn / Pair of adult Trumpeter Swans (Cygnus buccinator) in flight. Skagit County, Washington. January.

Gerrit Vyn / Greater snow geese (Chen caerulescens) taking flight at sunset during migration. Montezuma National Wildlife Rescue, New York, USA. March.

Gerrit Vyn / Nene / Hawaiian goose (Branta sandvicensis) Hawaii. April. Vulnerable species.

Staffan Widstrand / King eider duck (Somateria spectabilis) male, Batsfjord village harbour, Varanger Peninsula, Norway. March.

Staffan Widstrand / Steller's eider duck (Polysticta stelleri) Batsfjord village harbour with red reflections on the water, Varanger Peninsula, Norway, March.

Staffan Widstrand / King eider duck (Somateria spectabilis) male, Batsfjord village harbour, Varanger Peninsula, Norway.

Sven Zacek / Eider ducks (Somateria mollissima) males reflected in a small pond, Longyearbyen, Svalbard, Norway. June.

Nick Upton / Mute swan (Cygnus olor) female and a young cygnet foraging in sunset light, Kennet and Avon canal, Caen Hill, Wiltshire, UK, June.

Andy Rouse / Mute swan (Cygnus olor) with wings raised defensively at sunrise, Wales, UK, April.

Andy Rouse / Mute Swan (Cygnus olor) courtship behaviour, Wales, UK, April.

Roger Powell / Small flock of Brent Geese (Branta bernicla) in flight..Texel Island, The Netherlands, Europe

Ross Hoddinott / Mallard duck (Anas platyrhynchos) drake swimming through reflection of house, Bude canal, Cornwall, UK. April 2015.