The steep decline in ringneck pheasant numbers in Pennsylvania started when the Pa. Game Commission began allowing the harvest of hens. When the inevitable decline happened, they refused to reverse their stupid policy, or admit their mistake. Instead, they blamed the decline on other things such as "clean farming".
It has now reached a point where native birds are pretty much extinct, and pheasant hunting is almost entirely put-and-take of stocked birds on State Game Lands. Stocked birds that do not get shot mostly become coyote food. The attempt to replace ringneck with Sichaun Pheasants failed miserably. I started hunting when Pa. was loaded with pheasants, and many times saw flocks of 40 or more birds. Once upon a time, it wasn't that hard to shoot a limit of cocks in a couple hours... without dogs. It just seems like the more wildlife biologists we have tinkering with things, the worse the situation gets.
Edit-- I will never understand how the same people who cling to the idea of global warming can also blame low bird numbers on exceptionally hard winters. And oh my gosh... who ever heard of wet weather in Spring?