Back in the late 1950s and early 60s, Noyes Slough in Lemeta was always open in stretches all winter. Don't recall any ducks sticking around then.

Down in Anchorage, Ward Gay used to feed the ducks on Lake Hood after freeze up. Their activity would keep sizeable patches of the lake open. Fellow aviators finally got down on Ward as it was getting dangerous for aircraft that might taxi or slide into one of the holes. So Ward would feed them for a while then cut them off. Poor Ward, I was with him one afternoon as he was lamenting that he had just given them their last feed for the winter.