Those are the decoy koi that I was telling you about Capewind , one thing I do know about herons though is that if they figure out that your pond is a soft touch to catch nice brightly coloured fish from then you wont get rid of them.DOUBBLE TAP said:Something that worked for a friend of mine was fake/toy fish that floated. He tied it to a rock so that it was just below the water line and came home the 3 of the 5 fake fish where out of the pond in the yard and pretty banged up but he never saw the heron again. And yes herons can float but its not there preferred method of hunting. I think that we all have a special type of hate for those birds Good luck.
You have to present to them a pond that is so hard to get to , that they say hey stuff this, this is to much hassle to get a meal from and leave.
You have to remember koi were thought up by Man the same as the goldfish when we first started messing with colours that in our fish were a mutation and is something you rarely see in nature which put the dinner sign up for these birds it says "fish you just cant fail to catch, all you can eat".
As such its up to us to defen our fish.
In the UK every koi keeper who lives near a river lives in dread of Otters Arriving as they will clear a pond in just a week end dependent on stocking levels.
rgds
Dave.