That has the making of a tough hunt no matter how you look at it. I guess I mict see it I could get up in the air at a good distance and see if you can spot where that are bedding. If you have a stiff wind in your favor you might be able to pull off a sneak attack. You did mention that the field was pretty grown up with weeds and grass. That should be able to provide you with decent cover to crawl your way in. To me it seems like a tough stalk, but likely worth the effort. Hey, if it were easy...