Use a weight-calibrated feeder.
The Droll Yankees® Yankee Whipper® feeder, for example, has perches that are calibrated to drop away from the feeding port when larger birds land. Yet, cardinals and chickadees can still use it.
Try feeders that physically exclude very large birds.
Feeders with no perches, short perches, caged tube feeders and most Nyjer® feeders (without trays) are designed to discourage larger birds. For suet, try an upside-down suet feeder. Woodpeckers can easily land and hang upside down, but grackles and other black birds find it difficult to perch.
Adjust your seed mix.
Avoid starlings by using our exclusive Bye-Bye Starlings mix. It consists of seed types that are difficult for Starlings to crack open with their beak type. Customers have also reported that Nutrasaff™ golden safflower or white safflower also tends to discourage both starlings and grackles from dining.