Taking up falconry or squirrel hunting is probably the most foolproof solution here, as has already been suggested. An easier but less surefire one would be to put in a raptor perch and hope something moves in nearby and starts using it. I will probably do this at some point to deal with the ground squirrels and rabbits in my garden. Would be cooler to become an actual falconer but that’s… a bit more of a commitment.