The following technique is used to find field nesting birds for field surveys and works great to prevent mowing over turkey nests. Take approximately 50 feet of heavy cord or nylon rope with a hand loop or handle made w/ dowell rod or a 10" piece of garden hose w/ the line run through it and attach 6" pieces of 2" PVC pipe at 5-6 foot intervals (I just drill a single hole in the PVC and pass a loop through and then over to secure to the line). I make flags out of 6' pieces of river cane w/ surveyors tape tied to the top and walk the field in parallel passes dragging the line and PVC through the field. When you flush turkeys, quail. etc. mark the location and carefully locate the nest. Place a flag to mark the nest and leave a 4-6 foot uncut swath around the nest when mowing. If you leave a sufficient border the bird will return to the nest and finish incubation. This technique is time consuming, very tiring, and extremely effective in saving the nest of ground nesting birds and for moving fawns. The rewards are more than just saving nests and I have incorporated it into an annual event utilizing the brawn of the "Jakes" that are annually invited to a "Jakes" hunt on our farm as a fun way to educate new hunters and tally nest #'s.
