mute swans...

Almost exterminated.
Because nature conservationists long ago have insisted on protecting the swans in Europe, they are still there. Otherwise we could only see them in the zoo or on a photo. After some temporary protection measures, a definitive protection was finally achieved in 1931. Almost all swan species were exterminated by hunting. In the end, the situation was so bad for swans that the protection was going to apply to the whole world.
In the second world war it went wrong again, there was hunger and again the swans got a hard time.
But after the war it went well again with all kinds of swans, and that's why you come across them for example on a bike path.
got this from natuur-natuurlijk