The mute swan is native to Eurasia, but wild populations exist on other continents as well.
Mute swans (Cygnus olor), in Kensington Gardens.
They are called mute swans because they tend to make a lot less noise than other waterfowl.
Mute swans are not uniformly common all over Europe, for example I rarely encounter them. These pictures were taken when I have spent half a day in London, England, and I took a walk in Kensington Gardens where the pond was filled with swans and ducks.
Like ducks and geese, mute swans eat pretty much everything they can catch in the water, animals and plants alike.
Mute swans like most other swans, are edible to humans.
Young mute swans may have grayish or whitish down but adult mute swans are always white. Interestingly their closest relatives are the black swans in Australia, not the other white swans on the northern hemisphere.
Further Readings:
Mute Swan – Cygnus olor.
Mute swan videos, photos and facts – Cygnus olor on Arkive.
Mute swan on Animal Diversity Web.
Mute swan on Wikipedia.
Hunting and Cooking Swans.