Yes herons are very adaptable and cunning. You got that right. And just like people when they find good fishing it's hard to dissuade them.
I know I keep repeating myself, but I believe the staked lines are the way to go as they are nonlethal and work for you 24/7 unlike scaring them away -- because you can't always be there -- as they can come in night while you're asleep. Even when I had a permit to take a couple out a year, one would always take it's place within a couple of weeks.
