Also heard a grouse booming in the same woods. Went out on a prairie on the other side. There were many crows, coven cifer sparrows, and horned larks. The crows must have yarns. The cifers were winging strong as dusk came on. Went back to the prairie about camp and watched the night howls. There were literally dozens of birds booming about. I walked out on a bare rocky spot and waved my hat at the, bird first. One bird immediately dove down at me and I thought it would boom but it turned about 10 ft from and made its noise. The crows were held up at an angle as usual when playing. This position was held through try-out the plunge and turn.