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 / Great crested grebe (Podiceps cristatus) adult with freshly caught fish. Tench (Tinca tinca) to feed to its young chick, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June

David Pattyn / Great crested grebe (Podiceps cristatus) adult with young on its back and in the water, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June

David Pattyn / Great crested grebe (Podiceps cristatus) adult with young on its back, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June

David Pattyn / Great crested grebe (Podiceps cristatus) adults courting and greeting each other to confirm their bond. Even with the young chicks already out they often show courtship behavior to each other, Valkenh...

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.

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.

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

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.

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 / Pair of Great crested grebes (Podiceps cristatus) courting, Cardiff, Wales, UK, March.

Andy Rouse / Pair of Great crested grebes (Podiceps cristatus) courting, Cardiff, Wales, UK, March.

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

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult feeding one of two chicks riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult carrying food (damselfly) for two chicks riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Marie Read / Eared grebes (Podiceps nigricollis), pair, one adult feeding chick riding on the other adult's back, Bowdoin National Wildlife Refuge, Montana, USA

Andy Rouse / Great crested grebes (Podiceps cristatus) pair in courtship 'weed dance' in morning light, Wales, UK, February.

Andy Rouse / Great crested grebe (Podiceps cristatus) swimming, backlit with morning light forming a bokeh affect on the water, Wales, UK, February. Highly commended in the Habitat Category of the BWPA (British W...

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.

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.

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.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship weed dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship weed dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) in urban environment Cardiff, UK

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance at dawn, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) with young chicks on back, Cardiff, UK, April.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance at dawn, Cardiff, UK, March. Highly Commended in the Animal Behaviour Category of the BWPA Competition 2015.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) rival males fighting during mating season, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance Cardiff, UK, March.

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.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) courtship dance, Cardiff, UK, March.

Andy Rouse / Great crested grebe (Podiceps cristatus cristatus) with young chick on back, Cardiff, UK, April.

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

Krijn Trimbos / Great crested grebe (Podiceps cristatus) carrying chick on back, The Netherlands, May.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in 'weed dance' courtship display, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) two in territorial fight, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) two in territorial fight, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) two in territorial fight, The Netherlands, March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in 'weed dance' courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) with head low to the water in aggressive display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) carrying chick while its mate approaches with food, Netherlands, May.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

Krijn Trimbos / Great crested grebe (Podiceps cristatus) pair in courtship display, The Netherlands. March.

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

Danny Green / Whooper swans (Cygnus cygnus) two in flight, during snowfall, Lake Kussharo, Japan, February

Danny Green / Whooper swan (Cygnus cygnus) in flight in snowfall, Lake Kussharo, Japan, February

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

Claudio Contreras / Waterfowl at dawn with mist, including Great blue heron (Ardea herodias herodias), American avocet (Recurvirostra americana), Northern shoveler (Anas clypeata), Xochimilco wetlands, Mexico City, Mexic...

Claudio Contreras / Aquatic plants (Typha sp.) with Mexico City buildings in the back, Xochimilco wetlands, Mexico City, January

Martin Gabriel / Mute swans (Cygnus olor) on water, Bavaria, Germany, February.

Jussi Murtosaari / Goldeneye (Bucephala clangula) with chicks swimming behind, Helsinki, Uusimaa, Finland, May.

Andy Rouse / Great crested grebe (Podiceps cristatus) on lake, Wales, UK, June.

Marie Read / Canada goose (Branta canadensis) adult swimming leading five goslings, Ithaca, New York, USA.

David Pattyn / Great crested grebe (Podiceps cristatus) backlit adult bird at dawn. The Netherlands.May 2014

David Pattyn / Great crested grebe (Podiceps cristatus) close-up of an adult with two young chicks. The Netherlands. June 2014

David Pattyn / Shelduck (Tadorna tadorna) male trying to grab a female to mate with her. The Netherlands. April.