I mix cracked corn in with the sunflower seeds! The chicadees and nuthatches throw out the corn so they can get at the seeds, then the squirrels and doves come and clean up the corn. One year I even had some pheasants getting corn off the ground.
I haven't seen pheasants in the woods for years, and I miss them. We're too far north for them to breed successfully, and the few we had were escapees from a farm.