This heron was trying to stand on flimsy branches in a fairly strong wind. He (or she?) kept losing his (or her?) balance and flapping violently to regain it. It was fun to watch! The original image shows that the bird has a patch that is missing all the feathers (do herons have brood patches??) on his right shoulder. It is hard to see clearly in this smaller version. I have noticed it on several of the birds in the rookery.
"The expression of the beautiful is in direct ratio to the power of perception acquired by the artist." (Gustave Courbet)