...Footnote: My gator decoys have not worked on the herons.
These have apparently have also kept the herons away for me. I got a pair after Zep's original post, and have been happy with them. I have them in my small CNBG forage pond, and have seen the herons circle, but not land in this pond.
Funny thing is 2 small mallard ducklings have taken up residence in this pond, and they pay them no mind. They swim all around them like they're not there.