I have to agree with MattBoyer, I believe it's not so much loss of habitat, but an increase in predators, i.e. Coyotes, fox, coons (eat the eggs) Bobcats and feral cats. The reason I don't believe it's habitat is, while I was living in Korea, There are tons of Ringneck Pheasants there, they are wild, long beautiful tails, and thick bodies. They are not hunted there. They have no Natural predators other than skunks, which you rarely see, only up in the most mountainous areas. I would see nesting pairs of pheasants right in the heart of downtown seoul, anywhere there was a small patch of yard with bushes. We would hear them cackling and crowing in the morning on the way to the subway. I asked my wife (an native Korean) if these were possibly pets and she assured they are not. They would nest in people's back yards, public parks, anywhere there was the slightest cover, and believe me it is SLIGHT in Seoul. Out in the countryside and farmlands, they are EVRYWHERE. It was really nice to see them, but it was hard not to want to hunt them, but who wants to end up in a korean jail?