My long-time friend, Harold Spangler in Charleston, loves his bluebirds and has been feeding them live meal worms. He has also been inadvertently feeding the starlings and grackles. They are eating him out of house and home.
He asked my advice on keeping the bigger birds away.
I discovered the secret a few years back – a domed feeder. The dome over the feeder bowl is adjustable and can be raised or lowered. Just lower it so the bluebirds can get in and larger birds – like robins and starlings cannot enter – and that’s it. Put the meal worms in the bowl and the big birds go elsewhere for free meals.
Do not, however, put sunflower hearts in the bowl unless you have a baffle. Otherwise, the squirrels will sniff out the seeds, chew through the domed feeder, if need be, eat all the seeds and ruin your feeder. I know that from experience. But domed feeders really work when it comes to feeding meal worms to your bluebirds.