My favorite climbing buddy for nearly half a century spent several years logging in the Cascades before I knew him. In his very quiet manner he could (and still can) always identify all the flora, fauna and minerals as we reached higher elevations. We often heard and frequently saw grouse, usually in trees on steep slopes nearing timberline. He told me that the ones most often heard at higher altitudes were sooty grouse, and that they "hooted differently" than their lower level cousins.
Is there indeed a clear distinction between the hoots of a sooty and a dusky? Having been fortunate enough to be virtually eye-to-eye as the hooted from branches, it would be great to confirm which we so often heard and saw.
Thanks!
John
NE Seattle