Commercial planes don't fly below 250m at all, expect when taking off and landing at airfields.

The structure of these "turbines" are that of planes which look like large birds to real birds, so they would stay away from the area with them.

I'd assume that these would be installed in large open fields, so it shouldn't affect migration patterns or bird localities.

I have seen eagles attack quadcopters thinking they were birds, but those are usually of similar sizes to what eagles' prey would look like, but obviously this shouldn't be a problem as well.

If it hits a bird, the bird will die. If it hits a plane, the plane will crash. Birds and planes should stay away.