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 Mute swan cygnets (Cygnus olor) riding on their mother's back, Birmingham, England, UK, May.

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

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

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 / Trumpeter Swan (Cygnus buccinator) trio flying, southern Alaska

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