Thanks for the replies. My interest in this begins with what this Amish farmer pulling a haybine with horses tells me, how he and his neighbors and relatives have trampled a lot of nests and eggs and often stopped just in time, or he would've killed many hens - they just lay there, acting like they're perfectly concealed, with no fear of a haybine, 4 horses or him. His haybine is pulled with horses at about 3 or 4 miles per hour, versus the 6 or 8 mph tractors pull them. Now lest you think it's because the hens aren't afraid of horses, or the little noise they make, his haybine has a 25 Horse Wisconsin engine running wide open powering the haybine, so it's as noisy as any tractor operating a haybine with a power takeoff. Plus he's yelling commands at the horses. Now the other ('english') farmers are the ones who tell me the same thing several of you confirmed, that they run turkeys through the haybines and that's just the way it is. Some of that might be exaggeration, but without studying enough commercial forage operators in prime nesting habitat at the right time, it's just hearsay. But I do know these Amish farmers to be the most Christian people you will find and they would not stretch the truth one bit about something like this.
There are several problems with the flushing bars:
1. Finding the money to pay farmers to use them. There are many farmers who like wildlife as much as us, but they have to make a living and using the device is cumbersome. It takes extra time they don't have. If we could raise the funds to pay farmers to use them in the most critical fields would we save a lot of broods? Without a study to determine their effectiveness, it'd be a waste of time and money for everyone. Maybe by doing a study we would find alternatives.
2. The only flushing bars ever made were variations of chains (some with bells) hanging off the front of a steel bar mounted off the side of the tractor or in front of the haybine. But that was in the 80's and 90's when they were smaller and went slower than they do today. And today some models can switch operating left or right, so how would the flushing bar switch? They're not going to be any more effective in getting a hen to leave the nest unless they're mounted about 25' in front of the machine and dangling heavy noisy chains about every 8" that would be prone to ruining the crop. Who's going to drive around with something like that getting tangled up in the fences and trees when they get close to the edge of the field? How many guys and how much time would it take to mount and dismount it? And does it even work at 8mph? What a mess if it comes loose and gets caught in the intake!
Without a complete study to determine how many hens nest in the fields versus the woods, we're just speculating. Maybe this has been studied before? Otherwise we can add this to the desired four part study mentioned earlier.
On May 16th I watched a hen (with a spotting scope from the second floor) go from walking across a hayfield, to a crouch lower and lower each step. Within 5 steps she totally hid herself in only 5" of grass (leg height) at a distance of 330 yards. Anyone ever see a bird do that? I believe she did that because she had started laying eggs in the shallow grass and didn't want the person walking on the road to know where her eggs were. To me, that's more proof of how hens would rather hide than run, once they start nesting (like the Dutch study says). And why they're so susceptible to haybines. Once they have eggs in their nest, they change from running at the slightest provocation to sitting tight. The closer her eggs get to hatching, the less she is inclined to be spooked by a predator, and for sure not by a haybine.
I propose some UW masters degree program researchers, WI-DNR biologists, or both conduct the studies using the turkey stamp funds (collected from every turkey hunter), to pay their expenses (not by the taxpayers). Or, since Ducks Unlimited funded the flushing bar studies, maybe the WI-NWTF would fund this one? Such a study might help us discover how to implant the fear of haybines in the wild turkeys DNA, so we won't have to wait a few thousand years for that to happen naturally.