I don't know what is causing any turkey decline because I still haven't seen it. Our turkey population has been stable for the past 36 years. We had a downturn in the late 80s, but that was entirely due to habitat and seemed normal. Once the habitat improved the turkeys came back and have been there ever since. The habitat is quickly declining due to timber cuts so I expect it to drop some in the immediate future, but that will be because they won't have a good place to live.
Everyone knows I don't like baiting, but I wouldn't think it would wipe out flocks. If 99% of the corn is good and only 1% is bad, it seems like that would result in isolated deaths, with the becoming more common around places that feed bad corn. That number could be significant in some places. I think it would be unusual to find turkeys that died; something will eat them almost immediately as everything in the woods wants a turkey dinner.
I hunt in 3 different counties and all 3 have a lot of turkeys right now.
All the labor of man is for his mouth, and yet the appetite is not filled.