I love to watch birds in the winter. It makes you feel needed! Feeding birds in the summer does not really support them. They have ample food sources to survive without the feeders. It just gives you a chance to watch them closer up. In the winter, though, you can see their demeanor change. I threw a bunch of seed out on top of the snow this morning and they absolutely swarmed it! And I am not talking about birds that normally swarm feeders in the suburbs like sparrows and starlings.
I have had juncos, purple finches, house finches, goldfinches, song sparrows, nuthatches, carolina chickadees, carolina wrens, tufted titmice, hairy woodpeckers, downy woodpeckers, red-bellied woodpeckers, yellow-shafted flickers, and, the prize of them all . . . an eastern towhee. That's just today!
They seem much more eager in the winter. They also chase other birds off much more often, even birds that normally have a very sociable nature. The towhee was jumping at the juncos to run them away from the thistle on the snow. From what I have observed in the summer, towhees are very shy and I have never seen them exhibiting the chasing-off behavior in the summer. It's gratifying to know a simple pile of seed on the ground can make it a little easier on the birds when their normal food sources are buried under 8+ inches of snow and ice!
Another important item you can provide in the deepest of winter is a heated bird bath. They don't need it to bathe so much as to have a clean, fresh, non-frozen source of water. I have one that mounts on my balcony railing without any holes to be drilled, so I can take it back down in the summer and use my traditional bird bath. It also gives you another chance to watch them up close. The colors just seem so much more striking against the snow! So, throw out some seed, put out some water and watch them flock to you!