I thought it was an escaped Muscovy Duck when I saw it while running the "wrong way" round Balderton Lake as I did yesterday. The local rag seems to think it is newsworthy. I found it sat with a bunch of Canada Geese on a wooden platform - exactly where it is in the photograph - and knew it was a Muscovy as my cousin Robert had one on his farm in Wales when I was little, that savaged anyone who dare enter the farmyard.
Took a huge chunk out of my grandad's leg! It was called Rocky. Obviously.