[pxc]

When it's really, really windy, my dog likes to stare out the window and bark at the trees for moving too much. (It took me a long time to even figure that one out.)

At the same time, he likes it when trees drop little pieces of fruit or seeds, like mesquite beans or pine cones. So on windy days sometimes he gets into a loop with a tree where he

  * stiffens up and barks at a tree for shaking its leaves
  * cautiously approaches the tree, sometimes growling
  * snatches something the tree has just dropped and runs away with it
  * runs around in circles with the tree debris, pausing and play bowing wvery now and then, batting it around with his paws, etc.
  * ... cautiously approaches the tree again

and so on, where he gradually gets bolder and more casual about approaching the rustling, swaying tree on each iteration.

(He's pretty suspicious of wind-related movement generally— he'll also yell at flags and banners sometimes.)

[noisy_boy]

You must show him Lord Of The Rings - The Two Towers with the walking trees.