Small flocks of Robins have been overwintering in our area for some years now, this, our coldest winter in 20 years being no exception. They seem to feed themselves plump on the many berries still on shrubs and trees as worms are still deeply buried in the frozen ground below several feet of snow. Apparently they can also feed on small minnows if the can find open water - see http://www.pbase.com/image/154745193 posted by fellow Pbaser, Len a few days ago.