View Full Version : Herons in for lunch...

06-14-2004, 07:20 PM
Hi there - I know this is a builder's pond site but thought I could get some helrp here - our problem is herons dropping by for a gourmet koi lunch.

We inherited a good sized, deep pond last year. It's in a small isolated area in our back yard surrounded by tall trees and a covered hot-tub. The herons managed to land and pick off the fish in the pond. After re-stocking for the 3rd time - we purchased a "scarecrow" - a motion detector water sprayer. We thought it seemed to work, but I caught a couple of smart ones that landed where they wouldn't get sprayed and picked up my prize koi again.

I've heard that they get used to "decoys" but our space is small back there. W added plants for cover and ran green nylon rope across the pond from the trees to our balcony but they easily glided around these.

I heard that running fishing line around the perimeter might deter them but don't want them to get hurt getting tangled up in them.

Any advice would be appreciated

Randy J
06-14-2004, 08:02 PM
I saw an ad for border collies trained to keep geese out of ponds. You could get one of them.
Sorry, I really don't have any other ideas.

06-14-2004, 10:41 PM
The most effective way I've seen that will keep herons away from your pond is to have some type of netting over the pond. That can be in the form of fishing line that is strung in several places over the pond, consequently forming a barrier that would keep a heron from being able to fly away from the pond's edge. There's something about the way a heron's mind is wired that makes them avoid any situation that will prevent an instant, quick, airborn retreat from the pond's edge. Herons are creatures of habit. In other words, they like to have things a certain way. If they can't have things in this certain manner, you greatly improve your chances of not having to deal with them. For example. When a heron wants to fish in your pond. It will fly in at a distance if it can and walk up to the edge of the pond slowly. This way it doesn't alert the fish to it's presence the way it would if it came swooping in with it's huge wingspan right over the top of the pond. They like to be able to walk up to the edge of a pond, but strongly desire to be able to instantly fly away from it (in a hurry if it's necessary). The ability to be able to fly away so quickly I would imagine is because they are so vulnerable on the ground. Dogs, people and other dangers could be lurking around the corner and the last thing that I'd imagine they'd want to be is stuck on the ground with one of these dangers. I hope I helped you.


06-15-2004, 02:15 PM
Thanks Victor - that was probably THE most insightful advice I've ever received. Of course you're right in seeing things from the creature's point of view - - now if I could only work that theory on my cat's behavior...hmmmm.

Thanks - I've already implemented your ideas with the fishing line.

06-15-2004, 04:50 PM
Glad to help


Acute Cut
06-17-2004, 11:18 AM
Just curious, i heard about a product they called "a scarecrow" as well. I guess it is a motion sensor activated to some sort of sprinkler or something. Anyone know what i am talking about as i dont?:D

06-17-2004, 12:00 PM
It's a device that hooks to your garden hose that starts spraying water like a reaction style lawn sprinkler when it senses motion within a certain proximity of where you place it. More often than not unfortunately, it winds up scaring people off when they try to walk up to enjoy the pond, but forget that the scarecrow is present and turned on. As long as you remember to shut the water off before approaching the pond, you'll be fine. Just remember that every time you want to feed your fish, or do maintenance, or just enjoy your pond up close, you'll have to turn that scarecrow off.


06-17-2004, 12:21 PM
I have to admit that it took some getting used to but after awhile it becomes routine to shut it off.

We have also been known to surprise a few of our guests :)

Ken Kesey
06-21-2004, 06:17 PM
That's some good advice Victor.

Another thing to do is make a "safe place" for the fish. Using a thin wide rock you could essentially make a little "hotel" for the fish. Make it in a way that the fish can get in but predators can't get in.

10-20-2004, 02:17 AM
Herons have a muddle of habits, some go in for neat extermination jobs, others may be picky, leaving the whole body of a fish and only eating the tail section. Go round a lake after herons have been and you will find a lot of variation in kill habits... Yes, they will fly around and around a location on many days before even landing on a tall tree close, for a more careful look... Very keen eyesight and hearing, indeedy...

After a serious heron attack, its quite normal for fish to go hiding for weeks, so you never quite know what has happened.... on a well planted pond with a lot of cover, most fish survive though you will notice the dramatic difference in their usual behaviour and wonder why.

Heres a few notes collected from observations and other folks experience :)

1) Predator nets.... cheaper than losing koi, downside, local animals can get trapped in it, snared. Not very pleasant explaining to your neighbor why their pedigree cat or dog lost its life or leg through strangulation. Predator nets are probably the most cost effective barrier method, a large mesh of around 4" should allow most varieties of plants to grow through it without tangling the mesh. Smaller meshes tend to be a mess with plants, strangled pets, and dead frogs by the time Spring arrives...

2) Barrier method.... Suspend strong fish line taut, 12" around the pond, herons hate trip wires. An elegantly simple way to baffle a dim fishbag on stilts, it often works, many folk have reported seeing herons 'baffled' this way.... a near invisible line that they can't see, bump into, cannot step over without tripping, is enough to stop them....

3) Hiding places... Step up cover within the pond... water lilies.... big bits of pipe, float large sheets of black polythene (trash bags will do) trippy stuff for tangling up predators... hiding places for fish. Surprisingly, many black plastic objects, when submersed become virtually invisible, in a natural setting, so the idea of this clutter in pond is not as bad as it sounds. I like this method, it creates a lot of hiding places and is virtually invisible to the usually attractive pond setting, it makes it very difficult for the likes of persistent herons and raccoons when they raid.... useful in winter when foliage is bare and fish want somewhere quiet, to hibernate, bare crystal clear ponds must be an easy target for predators....

4) Pond design... When you make a pond, make 45° sides, herons have gangly legs, they like 'easy walking' conditions, they hate 'trippy' pond surroundings... The one common weakness of predatory birds is the vulnerability of their gangly long legs, they absolutely rely on an easy landing place, and an easy stroll into the pond, handy shallow terraces are a big help....

5) Trapping... I can't be so fiendish, I cant advise you put out snares... a simple loop of fish line can lock onto a predators leg. Nasty way to die, that

6) Shooting... Not everyone in the world live in areas where herons are protected, or rare... I can't recommend a .22 air rifle, a bit politically incorrect, even though a heron is easy to hit at 200' with a decent scope, unfair, too easy I guess. Anyone who has used a rifle properly could hit a quarter at 100 feet so for the squeamish, clipping some tail feathers is quite possible .....or hit a bucket placed beside the pond loud and close enough to frighten the bejasus out of the vile fish bag... that is a quite effective clean way....Alas rifles in most peoples hands are quite counter productive, you can waste a lot of time waiting for the opportunity to use it, to learn how to be competent with a rifle and the consequences of a bad tempered person with a lethal tool is well, unpopular...

7) Sprinklers... For the flash and the opulent, linking a motion detector and a sprinkler might provide some amusement to scare off the dratted bird. Or, a hose with a timer, that briefly blasts water every 15 minutes or so, enough to startle a pest... if the risk of absent mind folk getting a drenching is bothersome, perhaps the motion detector could be linked with an emergency service strobe light, that would be enough to freak most long leggedy villains away :)

8) Aquatic plants... A heavily planted pond makes life very difficult for predators, even though the big bright dumber fish will always be taken first, shy nervous timid (smart) fish and the little 'uns ought to be able to find good hidey holes easy... the rafts of aquatic iris, water lilies make life very difficult for hunters to find fish, let alone move around or risk stumbling among

9) Fish feeding routine.... Have a special food signal, like tap a stone three times at feed time. You don't want your fish to associate every visitor to your pond, with a free meal.... one day it will be a heron, looking for freebies...

10) Heron statue... what a novel idea, picturesque even. They always seem to be coming on the market, second hand. Never heard anyone had any success with them, other than folk who sell them, I guess....

11) Sonic guns.... There is a very promising new device coming onto the market.... sonic 'guns' that fire a narrow band of extreme noise in a confined direction. Link this to a motion detector and it really will do the job... herons are incredibly sensitive and nervous, a violent sound like that pointed at the pond area will really blow them away when they trigger the sonic gun. Because of the controlled direction of the sonics, its not likely to bother neighbours, much.... Very promising, that method..... Another device that can be activated by a motion detector is a strobe light, the sort that emergency vehicles use, that can drive off predatory birds which are unable to hunt with such a dramatic distraction... that has been reported to keep fish ponds free of attacks recently, not a big deal to find and install.

12) Baseball bats. Herons by nature are incredibly careful hunters, you won't get within 50 feet with a bat. Anyone thinking of trying such a method will quickly learn the bird is a lot smarter than them, and that will be just sooooo embarrassing....

13) Crocodile heads... that might well work in Southern areas where crocodiles are well known predators, however, many herons are not familiar with crocodiles at a young stage, or have never seen them before so in many cases it just won't be noticed, except, in areas where crocodiles are well known...

14) Tin traps.... Another 'scarer' for discouraging prowlers could be a tin trap, a big can with some large round stones to rattle loud within, this can be precariously perched and attached to a fishing line trip wire along likely approaches. Very effective after dark and around morning and dusk...

15) Shishi odoshi.... Another critter scaring method, which may or may not work against predatory birds but is supposedly effective against deer is the Japanese 'shishi odoshi'....If it is a little out of the way without too many neighbours close, this old japanese design for scaring deer might be effective, made out of a few large pieces of bamboo and relying on a trickle of water to keep it going, it's supposed to work on deer, though, moose might be a different matter... It could drive you nuts if you made it a little loud...

Checkout: http://www.canadianhomeworkshop.com/weekend/shishi_odoshi.html

16) Koi 'decoys'.... Believe it or not, folk are reporting they work. Someone somewhere makes rubber? koi which you can moor in the pond in an open area... looking like a dozey sitting 'duck' the heron sneaks up, batters at it a few times, tries to yank the decoy koi plus anchor out of the water, only to discover it can't....

regards, andy

10-20-2004, 02:18 AM
One of the worst aspects of heron attacks is worrying... You know the fish are missing... were they stolen, by what... how? That can really make you fret some time

With good heron defenses, casualties can be slight or zero, but, the fish may well be in hiding for weeks...

You can pat yourself on the back, for picking the more faster moving koi when you originally chose your fish, these are nature's 'survivors'

The time when predatory birds go pond hopping is determined by local factors, drought, floods or freezes have made difficult or their usual hunting places, early morning and fog is a factor to make them bold enough to go close to places where ponds are, compact sushi bars preferred....

Herons are creatures of habit, they will 'tour' their favourite water holes quite religiously. When they spot a new pond with fish they will add that pond to their schedule and turn up like clockwork with the same routine...

Their eyesight is extremely good, it is something of a big advantage if the fish turn out to be garishly bright koi or goldfish... Not unlike a neon sign shouting 'sushi bar' loud and clear...

The loathsome fishbag on stilts might circle a promising pond a couple of times about 400 yards away, checking the whole area then appear to disappear over the horizon... They will disappear if they have spotted anything lurking, perhaps a cat, or fox is about...

Several minutes later, they will overfly it once or twice, gliding quite slow, to bank and turn and seem to go away. Five minutes or so they then come very slow, steady and at a low height from a completely different angle as if to take by surprise any skulking entity... hedgehopping, literally...

Should they spot one little thing that frets them, they will abort landing...

They want the pond all to themselves, with no complications...

Only then, when they are absolutely sure it's safe to plunder, will they come in and land in a high place overlooking the pond. Perhaps a chimney, or a small tree close to the pond.

Herons quite often explore ponds in gardens during times of poor visibility, fog, at first light when their usual haunts have become difficult, for example when floods have clouded waters, or when ice has formed, the conditions for likely heron attacks can be predicted if you keep an eye on the weather forecast...

When they have landed at a high vantage point overlooking the pond area, they really take their time with those beady little eyes, to make sure nothing is lurking before flapping to the best landing spot close to the pond...

I is not unusual for them to go about in pairs...

Should your pond be netted they will go to some lengths to try and get within, finding or any gap that they can... When they are safely within the net, that is a good time to, errr....

...surprise them

regards, andy

jd boy
10-20-2004, 09:38 AM
personally, creating barriers of fishing line, putting netting across the water, or having those korney aligator things negates the entire purpose of having a tranquil water garden.

Proper construction eliminates predator problems by giving them some area of refuge. An aquascape style pond naturally does this by providing all sorts of holes and hiding spots. We generally try to build some small "swim throughs" or caves where fish can hide. These areas also promote breeding!

Couple this with some aquatic plants and your plenty safe.

10-20-2004, 10:25 AM
I also have a koi pond. Our first pond was 34" deep with a few shallow sides. Get rid of the shallow sides if you have any or can. That is a wide-open invitation. Heron love to walk in and help themselves. Also they cannot catch fish lower than they stand.

(1) We have a "scarecrow" also and it has worked. What setting are you putting it on? We have ours on 6 or 7. Make sure to check the battery. We usually have to change ours a few times a year.

(2) We did put a grid 6 inches (the length of the pond) apart of fishing line over the old pond. The whole purpose of the fishing line is Herron have an instinct of not getting tangled and that deters them. Make sure it's the shiny stuff so they can see it. We used 6 inch galvanized nails to secure the line.

(3) We also added spindrifter bottom drains in the new pond and the constant movement makes it hard to see the koi.

Do they have any place to hide? Our deck hangs out over the pond. I remember one of our newer koi got to see the Herron and he just froze while the others were hiding. We had a cave in our old pond. Good and bad idea, they would hang out in there most of the day; however, without the cave, now they have to swim.

Our new pond (5 feet deep) does not have any shallow sides only a 2 foot shelve so we can get in and out of the pond. We still use the scarecrow but not the fishing line. The construction of our pond was to eliminate an open invitation to the Herron.

I saw a Herron land 3 times (in 3 days) by our old pond and have not seen one since our new pond was put in in July. We have lakes and a fisheries near by and now they leave us alone. Now will be the time they are migrating.

Hope this helps!!

10-20-2004, 10:37 AM
(4) There is also an electric fence made for ponds. The only bad thing it is not real attractive but they say it will do the trick.

The other items I can live with and really dont detract from the pond itself. You won't notice the fishing line as much as you think.