Winter Birding

We recently purchased a bird bath heater, and it has been a hit. Apparently, birds do need drinking water during the winter just as much as during the sweltering summer heat. Keeping it filled and clean in these frigid temperatures can be a challenge, though.
Because of the icy weather, I have been birding through our kitchen window lately. The other day I watched a crow fly into our neighbor's pear tree. A Cooper's hawk hiding in said tree did not put up much of a fight, but flew across our yard and disappeared. Crow - 1, hawk - 0.
Winter brings many birds to our yard, including more than a dozen red-winged blackbirds yesterday. A recent newsletter by the Audubon Society of Western Pennsylvania alerted me to the fact that those reddish finches I've seen lately are probably common redpolls. I hope they will still be around when the weather releases its icy grip.