Help figuring out what happened to my fish

[lovekoi]

Something clean out the fish/koi in my one pond several days ago. Never saw the guilty party so trying tofigure out what it was. The fish just disappeared. There was no mess to the plants or river stone that lines the pond so what ever it was it got in and out without disturbing anything. It must have ate aprox 20 plus fish and koi the were around 10" inches big so it must have had a huge appettite. At fisrt i thought must be a heron but now a few days later i wake up and there is animal scat near the pond. A little research has me thinking the scat is from a raccon/possum/skunk. Not sure if it is a coincidence. Can anybody offer any insight as to if it was a raccoon, possum or skunk if they could clean out a pond that is filled with lillies, water hyaniths and water lettuce surrounded by a river rock border and not destroy or leave a trace they were there. The really small fish survived the attack as they were likely able to get through the holes in the milk crates that the shallow plants sit on. This was another reason i thought might be a heron cause a critter would have torn up the pond to get at every last fish it could. Please offer me some insight or personal experience.

 

[addy1]

My guess would be a heron, the other critters would have tossed your plants around. the heron can fish with you never knowing it was there.

 

[HARO]

Possibly a mink or otter. Deffinitely not a raccoon! They destroy everything. :grumble:
John

 

[Waterbug]

10" = 0.6 lbs * 20 = 12 lbs
A large Great Blue Heron would weigh about 6 lbs so eating twice its weight seems unlikely.

Skunks and possums have virtually no way to catch a fish. All things are possible but them catching 20+ fish...all the fish in a pond...I'd say those odds as impossible.

Raccoons are also not great fish catcher, but at least they wouldn't mind being in and around a pond and can catch fish trapped in plants or a shallow area. But to catch every single 10" fish in a pond and not leaving the pond torn up I would stay is virtually impossible.

My guesses would be...

1. Human removed them.

2. Mink. Skilled fish hunter, carries fish away, can cache the fish instead of eating them right away. Very common animal although most people don't know about them, are almost never seen. Good at getting in and out of the pond without damage.

3. River Otter. They can eat 25 lbs of fish per day and are very good fish hunters. They could get in and out without tearing up the pond too bad and would ignore small fish.

 

[anitapond]

I've personally had my pond cleaned out by coons. They made a mess of the rocks and plants. Shredded the lily leaves trying to get the fish which clogged the filter. You would definitely know if it was a coon. Since then my pond is netted 24/7. It's not as pretty, but pond is safe.

 

[lovekoi]

Mystery is solved. It is a heron. Wife caught him in the act this morning coming back for more. Now just got to get rid of him.

 

[slakker]

Minks can definitely be an issue. My friend (brother in law's brother) in Mississauga had his cleaned out in the last few years and he's kept koi for over 20 years. He was telling me that some misguided tree huggers let loose a bunch of minks from a local farm in the area a few years ago and they're feral now. I wouldn't be surprise if they've made it out to London too.

 

[HARO]

They wouldn't have to travel from Mississauga to London, there are plenty of wild mink in the area.
John

 

[Waterbug]

So the clean out of 20 10" fish must have happened over maybe a week.

 

[lovekoi]

Very well possible could have happened over several days or more then one heron. Everything I read about them says the are territorial hence why decoys are supose to work. But when I mentioned the missing fish to my neighbour a few doors down she said that the heron(s) have been around for a couple of months and cleaned them out and another neighbour out several weeks ago and that 2 of them were sitting on their roof at the same time. She also told me that they thought they got completely cleaned out but just in the last day or so some fish started to come into site as they must have been skitish and hiding for a couple of weeks so maybe there is hope that some of my bigger fish did survive and are just hiding cause the heron keeps coming back. Not holding out to much hope for that though. Most ,ikely it happened over several days and I didn't notice till the weekend they were gone. Thankfully the majority of my koi were in my newer pond.

 

[lovekoi]

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[Waterbug]

Everything I read about them says the are territorial hence why decoys are supose to work. But when I mentioned the missing fish to my neighbour a few doors down she said that the heron(s) have been around for a couple of months and cleaned them out and another neighbour out several weeks ago and that 2 of them were sitting on their roof at the same time.

They are territorial but that doesn't mean they like a 1 sq mi territory. Just means they don't generally hang to together.If one sees another one catching a fish they might try to drive that one off their spot. And if hunting is good their territory might be very small, like 10 sq ft, pecking range. Bears are territorial but can be very close to each other under certain conditions.

If by decoys "working" you mean draws them in then yes. If you mean keep herons away then no. As you say, Great Blues are territorial, when one sees a Great Blue decoy it's likely to come see what that bird is eating. They seem to have the mind set of "there's a another Great Blue...cool...I'm going to go kick its ass".

There's a bunch of very funny videos of Great Blues ignoring decoys. They seem to catch on very quickly. There's also some videos of Great Blue stacking up at fish farms. When one catches a fish another one flies in and drives off the one that just caught a fish. This repeats over and over with Great Blues perched all around wait for their turn.

However, the people selling the decoys like to spin the territorial angle their way. Great Blue hunt fish, retailers hunt suckers.

 

[addy1]

The floating gator heads I had seemed to work, I watched the heron stare at the head then leave the pond. One did ignore the head in the one end of the pond, it was totally covered in lilies. It flew over the chicken wire fence, did a dive bomb into the pond, tangled in the fishing line, baled for the sky when I yelled at it.

This year the netting I hung high over the water, wide weave, black, maybe they see it. I have not had one heron arrive, so far, they do fly over every darn day, most of the summer. I am beginning to think they can see it. No clue until summer is over and they are gone for the winter.

 

[brc]

I hate to admit it, but every time one of these heron threads comes up, this is what pops into my head:

http://www.airgundepot.com/rws-350p-magnum-22-caliber-1000-fps.html

 

[fishin4cars]

I had a heron clean my pond out three years ago, In four days it got 20+ fish, some near the 20" mark. The two biggest it removed and left on the ground then came back to resume the hunt. I guess to get them out of the way so it could continue catching smaller fish. Once they find a honey hole they are really good/bad at what they do.