Attacked

I am in Yellowstone for a few days so most of my posts will be from beyond Minnesota.  My first stop is to photograph some dead trees in the snow. Suddenly I hear a clucking and feel a tug at my sock. I look down to this gray bird attacking me.  It was relentless almost jumping into the car. Nothing would stop it. Finally I gave up. However, despite the danger I did take its picture. I believe it was a female blue grouse trying protecting a nearby nest.