Pottsy:
The only control I have for now is that the island is some 65' or so from the east shoreline and the bridge to the island has a 3' high gate across the dock. The ducks and geese freely roam the entire lake and shoreline while the guinea fowl were wing clipped so they will get familar with their surrounding before they release their new flight feathers next summer and fly to the mainland but hopefully return each night to roost in their duck/guinea house with all the trimmings. My only problem may be when the ice freezes......hopefully the ducks and geese will go to the open water of the windmill aerator near by and the guinea's will fly up to the highest point for protection. So far all the ducks and geese have survived, by feeding them from the island near nighttime and having them remain there throughout the night. Hopefully, in the spring I will add a few more types of geese and ducks such as African and Chinese geese etc. Also, I may add a few turkeys and laying chickens to the mix and continue to build another floating dock from the 1st island to the 2nd some 60' away so the birds that can't swim, can walk and forage for insects etc. Regards....
Rowly
