I have no idea how to
feed a certain bird species without attracting the unwanted ones.
We buy a songbird mix that the cardinal seems to like. These mixes have sunflower seeds, cracked corn, and millet plus some I don't know the name for.
The cardinal will pick out the seeds it likes and throw out the seeds that the cardinal is not interested in.
We have woodpeckers, bunting, and several other kinds of birds,
The small birds gather on the ground to eat what the other birds threw onto the ground.