Instructions
Put away all bird feeders and seed, particularly feeders filled with mixed grain and seed. If you are an avid bird watcher and feed the birds, this action may seem extreme. However, since grackles move in large groups, completely removing any potential food source for at least a week might urge the grackles to move onto another place for food.
Replace tray and platform bird feeders with caged tube feeders or weight-activated feeders. Changing feeders will prevent grackles from getting at the food, but still allow smaller birds to eat. According to Bird Watching magazine, the tube and weight-activated feeders should still allow birds such as nuthatches, finches, cardinals and other smaller birds to access seed.
Clean up new and old mixed grain and seed from the ground using a rake. Easily accessible food on the ground encourages flocks of grackles to stop to feed. Bird Watching magazine recommends reducing the amount of seed birds throw out from the bird feeder by using black-oil sunflower or hulled sunflower seeds as well as safflower seed.