It seems as though it should be that hard to come up with a deterrent.
I’ve got a natural enemy to deter them: bats.
Baseball bats.
I watched two huge buzzards picking away at a dead woodchuck or something. They suddenly hopped/flew 20 feet away. A little hawk landed on the woodchuck and pecked away for a bit then flew up onto the power pole.
The three of them kept this up for I don’t know how long. After about the sixth time I got bored and left.
Anyway - maybe some fake hawks?