It was in fact a cold frosty morning before the sun rose, then it was just cold. While it may appear there is open water, this was limited and restricted by the ice that had formed and taking a long time to clear. What always surprises me is how various species get along quite happily with each other, to a point, as long as 'my space' isn't violated, yet others simply invoke aggression. Here Teal and Wigeon relax happily together... safety in numbers and always someone on watch... while a small number of Black-Tailed Godwits moved through feeding on whatever they could find.
One reason there are so many images of Wigeon is because if you look carefully there is a male with far more green showing around the eye than others. There have been various discussions about this, but no real answer that I know of to date ... some birds do, some birds don't. Any comments welcome.