When I started shooting chucks in N.E. PA. (1983) the places we hunted were a virtual golf course of chuck shooting small 50 -75 acre fields with woodlots between. hand laid stone walls around all the fields and poor farming practices. The would cut hay twice a year, never all the way to the stone walls and used little to no chemicals. Around 1993 they started selling stone walls for a profit to stone masons. The farm also started spraying for bugs and weeds. Less chucks was the result...... by a lot. Around 1997 the dairy farming came to an end as the older farmers retired and their son was busy mining flag stone. Farm grew up and chucks vanished into the undergrowth. I hear that a few years ago that the fracking took hold there and a few wells are on this farm...