King
There are several ways that preserve hunts are put on. You can have someone "plant" the birds (dizzy them and place them on the ground in a disoriented state) or you can simply release the birds in the middle of the property. To me planted birds are only good for dog training or maybe teaching a young hunter the fundimentals. There is a state run facility near where I live that releases birds and I enjoy hunting there very much. It's still not nearly as challenging as wild birds, but it keeps my dog in tune and I increase the challenge by using either one of two .410's I own or lately a 36 gauge percussion sxs. Yes, not nearly as many birds hit the ground dead, especially with the 36 gauge, but my golden retriever quickly (and always) finds them for me.
Dick
I started to put together a numbers answer for your original question, but with on-going family health issues turning my life upside down (my wife has been fighting breast cancer for several years now) I just couldn't come up with a meaningful answer for you.
Steve

Approach life like you do a yellow light - RUN IT! (Gail T.)