I had a similar conversation with a neighbor who shared a half mile of fence on one of our farms. His place was 200 acres and ours was 240. We had one covey of quail along the fence between us. Both farms had clear barbed wire fences and fescue pastures.
He said when he was young his farm alone had 10 coveys. I asked him about the fences at the time and the pastures. He said the fence rows were all grown up in brush. They had dairy cows so they grew corn, milo, and lespedeza. Nuff said.