Plant in layers, and supply a water source. You may have to go out into the wild areas to see different birds. Don't bame the lack of other birds on the crow or starlings. It is because of our human habits. Tearing up nature and redoing it to fit our needs.
Crows are just smart enough to change with the times.
They are no way responsible for harming any species. In fact they strengthen species by culling the weak. All are good. Gold finches just like thistle seed. Some birds just eat insects and so like a pond.