This female mallard had no problem standing in the snow; the ducks here in Calgary seem well adapted to the winter. I am not certain how many actually migrate and how many stay here, but I do know there are some here year-round, and they seemingly have adapted to the cold weather. The rivers don't always freeze over, and we do experience breaks from cold snaps with Chinooks that blow a warm westerly wind into the city that can dramatically change temperatures in a matter of hours. I think the patterns of female mallards really look excellent in black and white. I find the level of detail pops even more than in color, which can also look great.