Song Sparrow (Melospiza melodia)

I've had just a few of these birds coming into the feeders with my mixed flock of Juncos and Sparrows. Yesterday there were three of these pretty Sparrows here. All the garden birds are feeding like piggies the last few days. Do they know it is going to be bitterly and dangerously cold by the end of the week? Yesterday I tucked a used Christmas tree over by the feeders as it has lots of dense branches that are good for roosting and staying out of the wind. I wish there was more I could do for my feathered friends to help them through the extreme weather coming.