I don't see any mention of the effects of predatory birds on the Sage Grouse. Every time I drive through eastern Montana or Wyoming I see more hawks and eagles than I see antelope. I don't think road killed deer and antelope are the only things that they are eating.
For the past 5 or so years there has been a bunch of wild turkeys that roost in the trees on the hill above my neighbors house. Every day in the winter months between 20-30 turkeys have been coming down into my and my neighbors yards. In the summers, the hens move down into the hayfields, but 5 o5 6 toms used to stick around the houses.
This past spring a pair of Red Tail Hawks built a nest in a cottonwood tree by the creek below our houses. Now I see the hawks every day, but I haven't seen a turkey in months.