don't really have fox squirrels here, but I have some local bird seed eating 15 hrs a day that will actually Chase the neighbors cats out of my yard
there HUGE fat as can be, between eating corn out of food plots and raiding bird feeders, acorns and sucking up apples as fast as they can
I'd say some here are just as big or maybe bigger(well heavier)
wish I knew someone that ate em, as I could hunt them for them and give them away , but no one wants them and I won;t shoot anything I ain't got a plate for!
location and access to food would be the big factor here I think over breed of them!