I haven't had access to wild birds, but I turned over a thousand of them loose 20 years ago for several years in a row. A lot of these birds were close to wild birds they were just a few generation away from wild manchurian birds. We has several springs that we did have several hatches of young chicks, and in some places their were birds for several years, but eventually they were all gone. I really think we just have too much thick cover which leads to more predators. I have shot pheasants in Iowa, Nebraska, Kansas, Texas panhandle and North and South Dakota, and one thing that they all have in common different from us, is they are all more wide open country. Eastern Iowa was probably as close to our cover as anyplace, and there are fewer birds there than anyplace else I have hunted. Its not the minerals in the ground as a lot of people claim, because eggs collected from flight pens will hatch. I don't know what it is, but for some reason there just aren't any pheasants from here southeast.