I know very little about grouse, but it's hard for me to believe that turkeys could be a significant nest predator. Turkey poults primarily eat insects, but after that their diet becomes mostly plant materials. I don't think they are ever gonna go out hunting for grouse nests.

However, they may very well compete with the grouse for some of the same foods, and could have a negative effect on them in that manner.

I've seen turkeys and quail thrive on the same land for many years, but the quail are now gone from the land that I can hunt. As much as I enjoy turkey hunting, I would rather have quail. I don't believe our quail decline is related to turkeys.

I don't know how it is in Canada, but where I live it doesn't matter what we think anyway. The state dcnr is gonna do whatever they wanna do, and what people think about it doesn't matter to them.