Chukar Partridge

This is a Chukar Partridge. I have lived just outside of Richmond Virginia all my life, and I have never seen this bird before. It was walking around in my backyard and making no effort to fly away. So, I grabed my camera and started taking photos, and I was able to get within three feet of it without any need to fly away.
I went to my National Geographic book of birds and found that this bird lives out west in places like Utah and Nevada and is a game bird that lives in high desert plains of western North America, as well as in Hawaii and New Zealand. So, how did this bird end up in my yard in Virginia 2500 miles from home? Come to find out that it is a game bird that is hunted and my bird book said that it is released in the east for hunting. So, all I can assume is that it was raised in captivity, as it was not affraid of me, and released somewhere near by for hunting purposes.