I took this photo a week ago in wetland in the Cynon valley. The duck was swimming with a group of mallards but doesn't fit with any of the pictures in my books of immature or eclipse plumage for that species. The closest match I could find for it was a female Garganey but it would seem unusual to see one in January as they don't normally visit our shores until later in the year. I'm not very good on waterfowl so any assistance greatly appreciated. Whatever the duck was, it was a striking bird with beautiful caramel-coloured plumage. Perhaps it's something really obvious but I'd still like to know.
Help put this duck out of its not-identified misery.