Matthew Maran / Mute swans (Cygnus olor) Highgate Ponds, Hampstead Heath, London, UK, February.

Ernie Janes / Mallard (Anas platyrhynchos) drake, Norfolk, England, UK. February.

Ingo Arndt / Falkland flightless steamer duck (Tachyeres brachypterus) calling on the beach, Volunteer Point, Falkland Islands, March

SCOTLAND: The Big Picture / Tufted duck (Aythya fuligula) drake calling, St John's Pool Bird Reserve, Thurso, Caithness, Scotland, UK, May.

Markus Varesvuo / Long-tailed duck (Clangula hyemalis) three males swimming and interacting, Vardo, Norway March

Markus Varesvuo / Goldeneye (Bucephala clangula) just taken off from water, quacking, Vaala, Finland April

Cyril Ruoso / Common eider (Somateria mollissima) female quacking portrait, down is collected from wild ducks on Skjaervaer Island, Vega archipelago, Norway, June

Cyril Ruoso / Common eider (Somateria mollissima) female quacking portrait, down is collected from wild ducks on Skjaervaer Island, Vega Archipelago, Norway, June

MYN / Corne van der Linden / Quacking frog (Crinia georgiana) male, Darling Range, South-Western Australia.

MYN / Corne van der Linden / Quacking frog (Crinia georgiana) male, Darling Range, South-Western Australia.

MYN / Corne van der Linden / Quacking frog (Crinia georgiana) male, Darling Range, South-Western Australia.

MYN / Corne van der Linden / Quacking frog (Crinia georgiana) female, Darling Range, South-Western Australia.