When Common Grackles camped out on my feeders in the spring, I got a Nuttery Globe Feeder to give smaller birds a chance to eat. Cage feeders like this one are sometimes the only way to keep aggressive nuisance birds from dominating feeders.
Each new season brings changes to the bird dynamics in the yard. So I tend to do some tweaking of the bird feeders or their placement each season. To reduce the amount of seed winding up in squirrel bellies, I decided to turn a ground platform feeder into a platform feeder on a pole. The feeder I converted is a Birds Choice Fly-Through Platform Feeder.