I went for a walk one afternoon up the huge hill behind camp and standing looking out over the lake I could hear this eery squeeking, so slowly I head toward the sound. As I am getting closer I cannot see animal which would be making this sound and around this birch tree I see what is going on. With the wind gusting high this fallen spruce had rubbed the side of this dry birch tree causing a deep cut in the tree. The gouge was warn smooth and sharp edges just by one dry tree rubbing on another of softer grain. Amazing what happens in nature.