Blue grouse often roost in large trees on the edge of a canyon or swale that allows a launch downhill into escape cover. In northeast Oregon a spot I often visit has a number of large fir trees along the edge of a very steep canyon - growing in a row about 150 yards long. One day years ago I walked the edge of this row of trees and flushed five blue grouse that launched from the trees, dropping like rocks into the bottom of the canyon, and missed all five birds. I swore to learn to learn to connect on these shots and did improve after some specific practice. This translated into better, but not stellar, bags of birds.
Here is a bird that I bagged while Pete and I were hunting last season near the Snake River. The bird flushed from a copse of trees, I shot and thought I had missed shooting through the screen of evergreen branches, But 45 minutes later, and more then 300 yards down the draw he 'escaped' into, Jesse found and pointed him - laying below a tree with his feet in the air. Lesson learned - follow up the birds that I 'miss'.
The gun is a Joseph Harkom 16 gauge boxlock that I sometimes carry when an ultra-light gun seems to be called for.