I was surprised the other day to see this mating display by a male blue grouse. It seems awfully late in the summer for him to be performing his ballet. (I’ll have to ask my friend Ben, the upland bird biologist.) I went looking for the grouse again this morning, and found only a few feathers. I assume I was not the only one to notice his performance. The short list of likely suspects: goshawk, lynx, coyote.