Foggy mornings present opportunities to experiment with high key exposures. It’s comparable to drawing on paper with charcoal or conte crayon. Crows, magpies, swans, Goldeneyes, Buffleheads, Ring-necked Ducks, Scaups, etc. have the strong blacks which make for bold contrast against a high key background.
Canon 10D, 400mm f5.6, 1/640 secs, f5.6, ISO 400, b & w