Mixed seed works well too, Bob. I often use that.
Hi, stja. It works on Starlings but better in the winter. I’ve never heard of a grackle being trapped and it would be illegal to euthanize a grackle. But, I agree, they are annoying!! I think it would be almost impossible to catch them in the summer with these traps. In mid to late winter if you use peanut butter as bait you’ll catch a lot of starlings. You also have to change the weight on the arm. Put one quarter on the arm and make sure it does a quick fast drop without bouncing.