80 acers isn't much ground and you will push the birds off quickly. Walk the fence lines and try to drive the birds into the center of the land. This will give you a better chance at them.
The thing you have to remember is the birds will gain back there wildness between now and season, if the hawks don't eat them first. The good part is it sounds like you have a holding pen from the bird farm and new birds will be coming in later in the season. Sounds like a great place to take a kid hunting.
Gselkhunter