Why are some ducks still here in winter?
Thanks for your concern for the ducks in your area. While ducks and geese usually migrate south, some do remain in southern Canada for the winter. Those that stay in Canada stay close to areas with open water and adequate food. If their food or water sources run out, they're likely to migrate to an area that can meet their needs.
Waterfowl freezing on the ice
If ducks do stick around during the snowy months, they adjust to the cold. For example, have you ever spotted a duck standing on a sheet of ice and wondered how they kept their feet from freezing? Here's a neat article about ducks doing this (without freezing their feet off!)