Likes been said, if you hunt a field stay back in the woodline a little. A field or high spot is the best place to be in the morning to locate a bird on the roost. If I hunt in the woods I try to position myself with lots of cover behind me, if they see past you and theres no hen, that can cause them to hang. I also like a setup with cover between me and the bird, so that when I get a good look at him he's in range. If a bird has covered some ground and he's definatly on his way I don't call, just scratch and maybe purr a little. I would say over calling or if he's in a strut zone are the main reasons for them hanging, unless he's out in a big field or opening, then he's just out were he can see and hen's can see him. Remember were they hang in the woods and youll know were to setup next time if it's not something you did that caused it. Heck, sometimes they get their mind maid up they've come as far as their going to and ain't nothin you can do to change his mind! Haha!

Good Luck!!