I just got back from hunting Sage grouse in Utah. The tail feathers are that of a male sage grouse. The problem is, they did not have the white chest. It was black. And all four birds shot were lacking the yellow eye brow. What is wrong with these birds? I have gone over the internet and cannot find anything that will help with my problem.
I was wanting to mount one, but I don't want to mount a immature or female sage grouse.
Is it just the time of year or what? Any help would be wonderful.

I know a new species of Sage Grouse had been identified in SW Colorado that is rare, something to do with Gunnison Plateau sage grouse. I don't know what part of Utah you were in but this could be spilling over to your area. The Co wildlife I believed stopped the sage grouse season in the area for protection of this species. You might do an internet search on the gunnison sage grouse

At least in SD the Sage grouse will not have their full plumage till later. Our season limit here for the last two years has been one bird. I used to drive out there to hunt them when I was younger but 450 miles is just too much anymore for one shot.