มute swans winter in the vicinity of the Wuhle River, surrounded by mallards and mandarin ducks. Berlin, Germany. Waterfowl in Germany. Mute swans, which have not migrated to warmer climes, winter in the vicinity of the Vule River, surrounded by mallards and mandarin ducks. The mute swan, Cygnus olor, is a species of swan and a member of the waterfowl family Anatidae.