Pottsy, it has been my experience that the birds are pretty well able to fend for themselves if they have open water available. I won't suggest cages because your Bears will of course tear them apart!! My biggest problem is with hens on nests. They will try to defend the nest when they start incubating and are easy prey for a lot of critters. I also have a windmill aerator although we don't get frozen in like you folks do. I believe Rowly is able to keep open water available with his. My wife wants to worry about the Geese in winter, but I point out to her that Goose Down is as good an insulator as there is.
Good luck!
Jim
