Apparently they are blown by the wind. Notice the blurred leaves and twigs in the background.
Correct. Wind and light rain, 1/6" exposure with VR for motion blur. I took a lot of pics at 3 fps and selected this one because many stationary elements were blurred by motion, yet the skeleton rider was not. It seems I had sufficient rotational camera motion in this image to blur stationary objects farther from the center while the center stayed reasonably sharp. Most images had even levels of sharpness on all stationary objects (from the further building to the dino's bolt teeth) due to f/22. In effect, I selected the image where the VR was only partially effective. Enjoying the added possibilities of VR!