Around here the ground squirrel numbers are nothing like they used to be. What we have is a dozen species of hungry hawks. Only the biggest ones can handle a rock chuck but any of them can eat a squirrel. The feds have been propagating hawks for about 20 or 30 years and they're very common now. We do have lots of rock chucks, though, if you can find a safe place to shoot.
Gotta love them feds and their birds of prey protection.