Yep, I read that herons are territorial so that's how I've kept them away from my fish pond - I have a little tin sculpture of a white heron there. The real, live white heron dined on some very expensive goldfish a few months after we moved in here, so I did the homework, re-stocked with 29 cent fish from Petsmart, and those little guys are now over 6in. long! No more herons fishing on my front porch.
