The reason why the turkeys and quail have gone down 90% in my area is due to the feral hogs. 35 years ago, had herds of turkey of almost a hundred birds running around! Ground nesting birds are extremely susceptible to depredation by these swine. Wish for the good ole days when we had only the traditional varmints and birds (road runners) who depredate turkey and quail nests to worry about.I've seen one thing that whittles their numbers down, and they stay low.
When timber shades out, the ground is bare and they have very little heavy cover.
Of course it's mostly worthless for deer at that time, and the turkeys hang up 200yds away….