FWIW

I have had the privilege to see Herons and alligators together in Louisiana. They have an amazing, almost constant predatory relationship. I was amazed to see how much Alligators (at least there) love to eat Heron and there seems scarcely a Louisiana Blue Heron that has not been bum-rushed by a Gator in nature. When a Heron lights in the swamps, it's not looking for, or worried about, you. It's looking for a gator.
In about four hours observing them through a car window mind you, an amazing three Herons were taken (uh, that's flat eaten) by Gators while they (Herons and gators) were photographed. Too bad the snatch is so fast.
Herons thus exposed to Gators (Uhhh, that live), are scared of Gators.
So what's the point? It has to do with where the Gator Guard is, in the scheme of things.
The worst decoy I have *ever* even heard of, is the inflatable snake. Bar none.
The second worst is the "Scary Eyes"
The third from the worst is any sort of plastic owl. What are folks thinking?
[A Golden Eagle might intimidate, because they handily demolish Herons on sight.]
The fourth from the worst is the actual Heron Decoy, because Herons, while highly solitary, acknowledge that if that other [rather rigid] bird can land (and survive), perhaps it's worth the professional indignity of fishing alongside the brave fellow.
Laying that plastic Heron decoy down, denting its widdle pwastic head, and putting a big fake bloodstain on it could be an underexploited and highly successful method. Let me know how that goes.

The second best decoy or scare is the Contech Scarecrow. This is because it's motion activated and in landing and lofting, the bird sets if off. Herons don't care a wit about water. They care about being startled.

The best decoy or scare is the floating adult Alligator head replica with the jewel eyes. Because you're capitalizing on the Heron's WORST, most common, most nightmarish enemy. Probably worse, >shudder< than a genuine Frenchman standing right there.

(It's not the fact that they deserve it, I only say that because the French actually have had arcane recipes for Herons, and other birds like them: “Some modern nations, the French among others,” says Monsieur Soyer, “formerly ate the heron, crane, crow, stork, swan, cormorant, and bittern.")

Better than any of those artificial decoys - is a dog. Blue Ridge Fish Hatchery had a Border Collie trained to run the levies and repel Herons. (It also herded the sheep that actually "mowed" those levies)

If you don't have a dog, it's okay, because netting is even better than a dog because dogs sleep, and do other things from time to time than watch the pond. Also, if a Heron is cornered, you should be aware that it naturally stabs at its attacker's eyes. Too bad for old Rover, if he's somehow less-than-immediate with the kill or just hacks the Blue Heron off.

I'd mention: If artificial decoys were so great, the fish farmers would use them (much more effortlessly) than wires or netting. But when you go see alot of the farms, you usually see those annoying wires running all over the place, (and for right or for wrong: a .223 Bushmaster Varminter AR-15 on a tripod on an advantageous window sill).



My newest pond, 6,800 gallons - is up and running, and will be populated Friday. There are sizeable Herons in Hothouse creek behind my house. I will be relying on this ponds' perfectly steep sides, uniform 45-inch depth and close proximity to the house for some protection. My two idget (but adorable) dogs are some backup and finally - the fact that I will probably seldom leave pond side will also help. If I really felt threatened by Herons though, I'd weigh the relative value of the fish against the cost and ugliness of:
- 1st: Netting,
- 2nd: A fake Alligator head, or
- 3rd: A Scarecrow.

I would not shoot a Heron. That's a serious thing if you're caught. [Besides, I don't think I could hit a Heron's narrow arse, even if I tried]. Even with a Bushmaster AR-15

The above is based on the rather sizeable number of people (from hobbyist to farmer) I've been privileged to discuss this topic with over the years. It depends upon the experiences of Herons in regional geography and how delectable your fish actually are. I happen to know that Herons have recently been discovered [and recorded] to 'squeal' with delight when they see top quality Momotaro fish, so probably no deterrent will work for those.

Have a great day!

Dr J

PS: Koivet Supermoderator PondGuyRob also supplies: "Anecdotedly.... another remedy against 'coons and herons, and sometimes even otters......
Buy a motion sensor type security light. Screw a plug-socket type fixture into it. Tune a radio to an all night talk station and turn the volume up just above the normal conversational level.
If the neighbors don't revolt, this trick seems to work fairly well. Human voices.... eeeeek!
Rob