Changes in our ability to hunt the predators, plus disease, little to no burning, and far more chemicals. The later being very damaging imho.
I've been hunting in 633 for the first time the past couple days and saw drastic differences in deer density/activity both days, how a cut is managed has a big impact on how many blacktails it will hold imho. A chunk of reprod I hunted yesterday (green diamond) had more blacktail sign in it than I've seen in years. The several I hunted today (GD, DNR) had a decent amount of sign but not nearly as much as I saw yesterday in the first cut. Difference between the two areas, from what I could tell was how much chem had been put down. You can tell by how much feed there is; if the cuts mostly reprod, salal, and grass...they probably chem'd the hell out of it. Maybe that first cut they got lazy with the chem or forgot to hit it

Needless to say I'm going back to the first cut tomorrow, where the feeds abundant and the BT's are there to eat it.