Your backyard bird feeders attract colorful avian visitors who can provide you with hours of entertainment. Unfortunately, feeders also attract big, hungry blackbirds who often crowd out more desirable birds. Prevent these interlopers from gorging themselves by filling feeders with food the blackbirds hate. Installing feeders the blackbirds are too big or heavy to use, or preventing them from ground feeding on feeder scraps, also helps to solve the problem (See Reference 1).
Undesirable Blackbird Food
Blackbirds have developed a taste for corn, wheat, millet and sunflower seeds. Eliminating these foods from your feeders will likely lead blackbirds to look for another avian buffet. Of course, you still want to provide food your desirable bird visitors will love. Make your chickadees, cardinals and nuthatches happy with safflower seeds. Hungry finches will flock to your yard for nyjer seed, also called thistle (See Reference 2).
If blackbirds can't get anywhere near the food they desperately want, they'll move along to the next bird feeder. To accomplish your goal, purchase a feeder with a cage that surrounds the feeding tube or bin. While smaller birds such as chickadees can flit through the cage bars with ease, the huge blackbirds will be left out in the cold (See Reference 3).
Blackbird-proof Food Dispenser
Even if blackbirds can fly up to your bird feeder, prevent them from reaching the delicious food inside. First, cut some length off your feeder tube perches. Pint-sized titmice, chickadees and goldfinches will have plenty of room to perch and eat. However, oversized blackbirds won't have enough space and will be forced to find another feeder. Blackbirds also won't like a hopper-style feeder with a weighted perch, as the perch's dispenser will close when the heavier blackbird lands on it (See Reference 4).
Banish Ground Feeding
Clever, resourceful blackbirds often congregate underneath feeders that contain their favorite foods. Keep the blackbirds from scavenging other birds' discarded seeds by placing a large trash can just under that feeder. While the blackbirds will be tempted to retrieve the seeds that drop into the can, they're very unlikely to fly inside to get them (See Reference 5).