From my experience, a wily heron will be desensitized to almost any deterrent (short of those that cause bodily harm) and will eventually not be scared away by them.
However, I have heard great things about the electronic sound deterrent that someone mentioned it earlier. Haven't tried it myself but have heard people rant and rave about it.
John
However, I have heard great things about the electronic sound deterrent that someone mentioned it earlier. Haven't tried it myself but have heard people rant and rave about it.
John