I just wanted to point out that metal leg bands are used in domestic fowl as
well as wild. Specifically, when poultry (including waterfowl) are being
shipped live they are often tested for the disease Pullorum, and once tested
are marked with a band (can be metal or plastic). I have chickens with these
bands, and a waterfowl breeder could presumably have similar bands on their
Here is a link to an image I found on line of a metal band used for such a
I'm not saying this makes the Pochard from a domestic source, just saying a
band doesn't really rule either possibility in or out.