I was in college at 30yrs old, like I said when I was averageing 125 fox a yr. The mange came in from the east, and continued across my 50X100 mile area that I regularly trapped and hunted. Our area with the wetland lakes was a fox factory. I could see the wave of mange going through by how few animals were in the east and then here and then later in the west of me. I know for a fact hunting did not wipe them out. Before I came here 21 yrs ago, there were guys shooting 100-150 fox a yr from here to Ft Dodge. Atleast one worked at the night shift at Morrels.
The plant closed and those guys mostly moved away. Then I moved here 5 yrs later. The fox were very plentiful, because we had the habitat. The mange took nearly all of them in two seasons. The prey base animals evidently didn't have much predation, so the coyotes that seemed to survive the mange better than the fox, spread out rapidly and took over, easily with all the food they needed.
A lot of fox only go 1-3 miles when spooked, but some go 5 miles or more before stopping, I know I tracked them down.
This is my 35th yr of fur harvesting, I can't even count how many predators I have taken in that time, close to a thousand atleast. 48 bobcats, for sure, about 220-250 coyotes in WY, 50-70 fox in WY, 750-800 fox in IA, and 3-400 coyotes since the mange epidemic in IA.
I would be willing to bet my last dollar, I'm not a betting person, that if I asked our local game warden where the fox went, he more than likely would say the mange also. It seems to me when they were overpopulated the mange spread faster and hit them harder due to the over population of fox, not over hunted fox.
My fur buyer used to go to s.e MT to trap fox for the live market, he averaged 10 a day there. He said I should go one yr, when I got there there were dead deer every where, very few were eaten on. There were no fox there, the mange hit there and wiped them out. This was right next to O'Gorman from Broadus. He has taken 20,000 plus predators in his 40 some yr career. He stated that the mange hit every state, except obviously PA, they are still taking up to a 1000 fox a yr they, one person is, others in 200-400 range. If they are over harvesting the fox in PA, then Phil there wouldn't have taken 1000 fox a yr for at least 3 yrs now. O'Gorman is taking about 1/2 to 1/3 of the fox and coyotes a yr that he used to, due to mange and other factors.