Strange White-fronted Mallard

Strange White-fronted Mallard

Observation - Strange White-fronted Mallard. Description: Apart from the obvious white breast, there is something very odd about this duck. I have seen it several times before and it almost seems like an outcast - always on the fringes of a mallard group, and it is unusually shy, always disappearing into the und

Apart from the obvious white breast, there is something very odd about this duck. I have seen it several times before and it almost seems like an outcast - always on the fringes of a mallard group, and it is unusually shy, always disappearing into the undergrowth of the far bank when I walk along. This is the first time I've seen it amongst a group of mallards - all loafing by the side of the water. When I walked along, this was the only duck (among 30 or so) which retreated to the water. None of the others bothered moving as I walked past as closely as a couple of feet in many cases. Anyone got any theories?