I have a couple of coveys on my 120 acres. 77 are in 10 year old hardwood CRP tree plantings, a few acres, including two ponds are more civilized and the remainder in old timber.
There are a couple of sayings (old wives tales) around here: Quail and pheasant don't co-esist and there are no phesant south of Interstate 70 through Illinois. I live south of I-70 and have both pheasant and quail. I've also got too many coyotes which likely keep both in check.