I believe the state uses the mechanical grouse to catch people who shoot grouse from a vehicle. Over the years people have seen the devices, driven up the road to park, and walked back to attempt to hunt the birds.
Those people are just asked to move on. They really haven't done anything wrong.
And, yes, populations of grouse that are off limits to hunting have been studied. Consistantly, bird mortality hovers around 90%. Same as hunted bird populations.


Best,
Ted