Aggressive birds are often attracted to the seeds that drop from your bird
feeder. Simply place a deep container below the feeder to collect
the seeds. The larger birds will not fly into the container and soon
will quit coming to your feeder.
In general, the larger, more aggressive birds prefer bread, corn, millet,
wheat and sunflower seeds. So never put out table scraps or
bread crumbs as this will only attract a larger number of aggressive
birds. Instead use seeds that these birds will not eat. Offer
thistle (niger) in a hanging feeder for the finches and safflower seeds in
a hopper or tray feeder for chickadees, cardinals and nuthatches.
If you follow these guidelines
the large, aggressive birds are likely to go elsewhere to feed.