Although you may be able to keep grackles from raiding your feeders, they may also be eating all the spilled seed on the ground.
How to get rid of grackles at feeders. Change the types of feeders you use. How do you grackle proof a bird feeder? Use black oil sunflower seeds to reduce spillage.
Here are a few useful ways to keep grackles away from your bird feeders: There are 4 effective ways you can get rid of grackles, blackbirds, and starlings at your feeder: Change what foods you feed birds.
Offer massive amounts of cheap food that grackles can’t resist, such as corn, positioned at least 15 feet away (4.5m) from your other bird.