It's a pond owner's worst nightmare.
You have dozens of fish that you've spent years raising into beautiful, beloved pets. They take treats out of your hand, and everyone who visits can't wait to check out your finned friends.
Then you glance out the window and catch a heron flying away with your 20-year-old koi.
Birds - heron in particular - and other predators, like raccoons, are the bane of any pond owner's existence. But don't take any drastic measures just yet. You have a few options for keeping the birds at bay.
At a Glance: How to Stop Predators from Eating Pond Fish
- Motion-activated sprinklers are the best deterrent in warm months.
- Floating alligator decoys work year-round.
- Decoy heron don't work well because they don't move.
- Nets are effective, but some people find them unattractive
1. Decoy Heron
Decoy heron are probably the best-selling predator deterrents on the market. Heron are solitary predators, and, the logic goes, will avoid a pond another bird has already claimed as its own.
But we'll let you in on a secret: Heron decoys don't work. At least not very well.
Heron are smart animals, and they'll figure out pretty quickly that the bird staring at them from the edge of your pond isn't moving.
If you do want to try your lucky with a heron decoy (or even a painted yard flamingo), moving the decoy to a different spot by your pond every couple days will probably give you the best results. Still, heron are intelligent birds, and your attempts to trick them probably won't work for very long.
2. Motion-activated Sprinklers
Motion-activated sprinklers are one of the best ways to deter predators in warmer months. You can find these sprinklers at your local pond store under a variety of brand names, the most popular being one called the ScareCrow.
The ScareCrow and similar motion-activated deterrents connect to your garden hose and shoot a small stream of water at anything nearby. It won't hurt predators, but it confuses them enough to make them give up after a few attempts at entering your pond.
We have found that sprinklers are the most effective way to keep predators like heron and raccoons away from ponds. A spritz of water to the face is a lot harder to ignore than a plastic bird. They do, however, come with a few caveats. For one, they have to remain connected to a garden hose, which may not flow with the look of your pond. They also run on 9V batteries that you will have to change every so often. Finally, these sprinklers don't discriminate between heron and Aunt Harriet. Any guests walking past your pond will be in for a surprise if you forget to turn off the ScareCrow.
3. Floating Alligators
ScareCrows work great in the summer, when you don't mind keeping a hose on. But what about winter?
Decoy alligators that float on top of your pond are surprisingly adept at scaring away predators. Unlike stationary heron decoys, they bob with the movement of your pond water, making them look like a legitimate threat to any critters eyeing up your fish.
4. Fish Caves
Fish in the wild depend on their camouflage to avoid predators. Not so for the orange and yellow koi in your pond.
The combination of brightly colored fish and shallow water in most backyard ponds make them the perfect all-you-can-eat buffets for predators. A few fish caves will help your fish hide, despite the brightly colored targets on their scales.
Fish caves are built-in underwater structures that give your finned friends a place to hang out when predators loom overhead. You can also buy cave-like shelters to place in the bottom of your pond, or add natural cover like waterlilies and lotus.
Things We Don't Recommend:
Heron are too smart for that (see the video above).
Some pond owners feel that the only way to protect their pond is to encase it in a bird-proof net. While a net will keep the predators out, it also obstructs your view of the oasis you've put so much time and money into beautifying. Still, some people swear by them as the only foolproof way of keeping their fish safe.
The one time of year when you should definitely have netting over your pond is in the fall, when dead leaves might otherwise overwhelm your skimmer.
The Great Blue Heron is federally protected by the Migratory Bird Treaty Act of 1918, so don't do anything drastic. Take appropriate safety measures for your fish and embrace your new backyard friends.
Getting Rid of Your Fish
Fish are one of the most enjoyable parts of owning a pond, as well as one of the most effective tools for keeping mosquitos away. Just keep them safe, and you'll have nothing to worry about.
What's Eating Your Fish?
So who exactly are the culprits making fish disappear from your pond?
If you live in the Northeast U.S., you probably have a bird to blame: heron, osprey, egret, hawk, eagle or some other type of feathered fisherman. Ground-dwelling predators, like minks and raccoons, also occasionally dip into ponds for a treat.
We've found that household pets rarely bother pond fish. Lots of our pond owners have dogs that drink from or even play in their ponds without issue. Neighborhood cats likewise tend to leave fish alone, preferring to watch them from the safety of dry land.
Fun Facts about Heron
It's good to know your enemy. Great Blue Heron are actually pretty interesting creatures, once you look past their fish-stealing tendencies:
- If there's a heron in your yard, you won't miss it. These lanky birds stand 3 to 4 feet tall and can have a wingspan of more than 6 feet.
- These big birds only weigh 5 to 6 pounds, thanks to their hollow bones and thin build.
- Heron are not bright blue like a Blue Jay, but rather a bluish gray with a bright orange beak.
- Heron don't dive for their prey. Instead, they use their long legs to wade into the water, where they stand completely still to wait for fish. When they see one, they use their long necks to quickly propel their sharp beaks forward and spear it.
- Heron live along rivers, shorelines and backyard ponds throughout much of the United States and parts of Central America and Canada. One subspecies that appears primarily in Florida is pure white instead of the more common bluish gray.
- Heron can hunt during the day and night thanks to special receptors in their eyes that help with night vision.
- Heron spend about 90 percent of their waking hours on the hunt.
- You can identify an in-flight heron by the S-shape it bends its neck into. This flying habit differentiates heron from the similar-looking crane, which flies with its necks outstretched.