Questions concerning attracting American bullfrogs to backyard ponds

[Wayfarin]

Hello, folks!

As I've mentioned on an older post, I was planning on changing the design of the outdoor red-eared slider pond (which, a year later, hasn't been built yet).

The pond would be designed in a way to keep our turtle contained, while still allowing frogs, dragonflies, birds, butterflies, bees, backswimmers, and diving beetles easy access to the pond. There would also be some small fish in the pond to eat mosquito larvae and pupae.

I originally planned to obtain bullfrog tadpoles for release in the pond. But apparently, it's illegal in our state to release tadpoles or frogs into an outdoor pond if they originate out of the state.

There's really no need to release tadpoles into the pond, though. Bullfrogs are common in our area and can colonize any backyard pond on their own.

However, does anyone have any suggestions regarding attracting bullfrogs to outdoor ponds?

I've heard that they prefer shallow, still, warm, and vegetated water. Our pond would be most of those things.

I'm aware that bullfrogs can be big. Do they need more space than other frogs?
The pond would probably be no more than 6' x 4' in diameter and 2' deep. It would probably have a capacity of only 150-300 gallons.

I'm also aware that they (and their huge tadpoles) hibernate under the ice. Are they hardier than goldfish, or do they also require an open area of the surface to allow oxygen penetration?

Also, if the pond is too shallow, will they migrate to deeper water before winter and return in the spring? I believe I've heard of frogs breeding and overwintering in different ponds from some sources, but I'm curious about how often that occurs.

I've also heard that bullfrogs tend to be nomads, moving from one pond to the next and rarely settling down in one place.

Any input, especially from experience, would be appreciated.
Thanks! God bless!

 

[WaterGardener]

We don't allow bullfrogs to stay here. They will eat anything that they can fit into their mouths and their mouths can open very widely. Their diet includes birds that they can jump up to catch, and fish up to 12" long, as well as other frogs. So those small fish you are planning to have would only be lunch for them.

We do have green frogs and tree frogs here. They are welcome to live in the pond.

 

[BKHpondcritters]

When it comes to ponds & frogs, the general rule is 'If you build it, they will come.' (provided they live in your area, that is)

That being said, a pond of that small size is going to be hard pressed to provide habitat for even one bullfrog. You might attract some young ones, but I'm thinking that when they start to get large they will move on. My pond is **much** larger than yours (3200-ish gallons, two separate levels & lots of surface area) and I've noticed that, although we have numerous bullfrogs of all sizes (as well as resident green & pickerel frogs and seasonal/spawning wood & gray tree frogs) when they get full grown they seem to 'disappear'. The adults tend to stake out 'territories' within the pond area, usually we have one pair that lives up top in the upper pool area and one pair that stays down below in the main pond. The smaller ones spread out where ever they find a bit of real estate. Unique markings & colorations allow me to keep track of who's who & who's where. They don't limit themselves to the pond when it comes to foraging, though, and will move out into the surrounding gardens at night (shine a flashlight & look for eyes in the dark!) And, yes, they do eat smaller fish, birds, etc.... whatever they can grab & stuff in their mouths!

Now a pond of your size will probably bring in a small frog or two. We also have a little container water feature up by our garage & we usually find a young bullfrog or two living in there during the summer. We relocate the back to the main pond in the yard when we take it down in the fall. Any frogs living in or around the pond are otherwise on their own as far as winters go. I don't worry about them & they all seem to do just fine.

 

[Wayfarin]

We don't allow bullfrogs to stay here. They will eat anything that they can fit into their mouths and their mouths can open very widely. Their diet includes birds that they can jump up to catch, and fish up to 12" long, as well as other frogs. So those small fish you are planning to have would only be lunch for them.

We do have green frogs and tree frogs here. They are welcome to live in the pond.

I'm aware that bullfrogs can eat birds. But bullfrogs need to eat, too.
And they are simply too big to eat nothing but minute bugs and beetles.

We could set up multiple birdbaths on our property where birds can bathe and drink without worrying about the bullfrogs.

I'm more worried about the cats and birds of prey that stalk our property. Cats are much worse predators since they hunt and kill birds as a kind of game.

I'm not worried too much about the small fish. Goldfish can breed like crazy given the right conditions and sufficient cover, and mosquitofish/minnows are almost guaranteed to breed like crazy.
In a pond of such a size, I'm more worried about overpopulation.

I also doubt that any bullfrogs of sufficient size would show up at the pond to eat the goldfish once they grow a foot long. Maybe I will only add one. If a bullfrog eats it, they are 25 cent feeder fish anyway.

I'm only worried about protecting the turtle, and red-eared sliders are big and aggressive. I'm more worried that she'll slaughter the bullfrogs and their tadpoles.

 

[WaterGardener]

Birds have to eat, too, and they spend a great deal of time on the ground. Bullfrogs don't stay in a pond 24/7. They leave the pond and hunt for food on land as well as in the water.

Do an image search on Google for bullfrogs eating and you will be surprised at what you find. They are serious predators.

But what you have around your pond is up to you. I happen to have a different opinion and everyone is entitled to their own.

I have many feeder fish along with others in my pond, but I have them for my enjoyment, not as food for other animals. I don't allow raccoons or owls or herons or bears to eat them either, if I can possibly prevent that. But each to his own.

Here is an example:

Google Image Result for https://i.ytimg.com/vi/mI0MjQaW8Lo/sddefault.jpg

 

[Jhn]

Agree with what was said about adult bullfrogs vbeing territorial, with your size pond who knows if they will stay or not. I have 2 that stay year round in about an 8x6 pond about 2’ deep.

Yes they will need an opening in the ice to winter over in the pond, as will any living animal. They still use oxygen even during hibernation, so not having an opening for gas exchange would be deadly, especially in a small pond.

 

[JBtheExplorer]

However, does anyone have any suggestions regarding attracting bullfrogs to outdoor ponds?

I've heard that they prefer shallow, still, warm, and vegetated water. Our pond would be most of those things.

Sounds like you have all you need to attract them! I'm not sure what they prefer in terms of pond size, but I imagine yours would be big enough for a few to call home. My frogs particularly love hanging out in the waterlilies and bogbean, and they'll also sit in between the sedges.

also, if the pond is too shallow, will they migrate to deeper water before winter and return in the spring? I believe I've heard of frogs breeding and overwintering in different ponds from some sources, but I'm curious about how often that occurs.

If the pond is too shallow, they might try to overwinter in it anyway and die. I don't know where you live, but 2' deep is probably deep enough for most areas in the U.S. It just depends on how cold it gets and how long it stays that cold. I live in southeastern Wisconsin and I don't think my pond has even frozen much more than a foot deep. But you will also need to make sure the pond stays aerated so the frogs can breathe throughout winter. They need good oxygenated water, maybe even more so than fish. Frogs are very sensitive to water conditions.

I've also heard that bullfrogs tend to be nomads, moving from one pond to the next and rarely settling down in one place.

This is true. Most of my frogs that are here in spring will leave through the year. New ones will eventually show up as well. Although the big ones tend to stick around, probably because there's so much for them to eat, including other frogs.

I'm aware that bullfrogs can eat birds. But bullfrogs need to eat, too.

I share this same opinion. Ponds are in an outdoor space and wild animals do what wild animals do. It's just apart of life. However, I do think it's also worth recognizing that our homemade garden ponds do tend to shift the balance in the predator's favor quite heavily. Our little garden ponds make predation much easier than big natural ponds. So I think it's good to have the opinion that nature does what nature does, as long as it's not to an extreme. When I saw one of my bullfrogs kill three birds in two weeks, it was time for me to intervene and re-home it. Otherwise it was just going to keep sitting in my bog and killing everything that landed there. Otherwise, bullfrogs are welcome here, and most of the ones that arrive are too small to be a threat in the immediate future anyway,

 

[Wayfarin]

Birds have to eat, too, and they spend a great deal of time on the ground. Bullfrogs don't stay in a pond 24/7. They leave the pond and hunt for food on land as well as in the water.

Do an image search on Google for bullfrogs eating and you will be surprised at what you find. They are serious predators.

But what you have around your pond is up to you. I happen to have a different opinion and everyone is entitled to their own.

I have many feeder fish along with others in my pond, but I have them for my enjoyment, not as food for other animals. I don't allow raccoons or owls or herons or bears to eat them either, if I can possibly prevent that. But each to his own.

Here is an example:

Google Image Result for https://i.ytimg.com/vi/mI0MjQaW8Lo/sddefault.jpg

They forage on land, but when it comes to birds, they prefer to drag them into the water and drown them before eating them. Bullfrogs consider catching birds on land to be difficult. Birds can scratch and peck and panic, and they aren't as easy to swallow alive as, say, a smaller frog.

All of the pictures online show the bullfrogs swallowing wet birds right by the water. They clearly drowned them. They're a bit like crocodiles. They don't catch many big animals far from water.

Also, I'm adding feeder fish for my enjoyment, because I enjoy watching them as well. But fish that breed prolifically shouldn't be protected from predators. Being overpopulated is a problem for the fish, too. And even if they don't breed, they are too cheap for me to want to deter bullfrogs from eating.

Teresa is the real star of the pond. Turtles sometimes turn on fish and eat them. They can kill frogs and tadpoles, too. But I don't plan on becoming attached to the fish or the frogs (although we'll do what we can to protect them from predation).

We are entitled to our own pond preferences. I'm more worried about Teresa eating the frogs than the frogs eating the fish. While I'd prefer to watch birds, butterflies, and other wildlife around the pond, I also don't mind if it's just Teresa and the big frogs.

You're also entitled to your pond preferences. Whether or not you want bullfrogs around isn't my concern, and there's nothing wrong with wanting to protect your pond fish. My concern is attracting them to our backyard pond, because I don't mind when they eat the fish.

 

[Wayfarin]

How big do they get? I've heard that they can grow to 8" long, but is that the average size?
Also, are big frogs only found in big ponds?

Even a 6" bullfrog seems a bit small to devour a 12" goldfish. Although I believe that the average goldfish is smaller than that.

 

[JBtheExplorer]

How big do they get? I've heard that they can grow to 8" long, but is that the average size?
Also, are big frogs only found in big ponds?

Even a 6" bullfrog seems a bit small to devour a 12" goldfish. Although I believe that the average goldfish is smaller than that.

I always have at least one massive bullfrog in my pond, usually a pair of really big ones. Definitely in the 6" range. The size of what they're going after doesn't really matter to them. They'll go after anything that moves, even if they can't swallow it. But they'll try for a while and eventually give up and spit it out for you to clean up. They'll even hop toward my hand when I'm cleaning leaves/debris out of my bog. They're just programmed to react to motion.

 

[j.w]

I always have at least one massive bullfrog in my pond, usually a pair of really big ones. Definitely in the 6" range. The size of what they're going after doesn't really matter to them. They'll go after anything that moves, even if they can't swallow it. But they'll try for a while and eventually give up and spit it out for you to clean up. They'll even hop toward my hand when I'm cleaning leaves/debris out of my bog. They're just programmed to react to motion.

View attachment 162312

Yikes they'd eat us if we'd fit

 

[WaterGardener]

I'm sure they would try!

Are they considered an invasive species where you live? Is that why it's illegal to release them? I have read that some states are trying to eradicate them since they are a threat to the native inhabitants.

 

[j.w]

Not native here and considered a problematic, invasive species here. Brought here from the east. They are prohibited for transport w/o a permit. The unlawful release of a prohibited aquatic animal species is a gross misdemeanor. A second violation within five years is a class C felony. I'll not be inviting them to my pond!

 

[Wayfarin]

I'm sure they would try!

Are they considered an invasive species where you live? Is that why it's illegal to release them? I have read that some states are trying to eradicate them since they are a threat to the native inhabitants.

Bullfrogs are native here. We live along the Vermont/New Hampshire border in the latter state.
Apparently, it is illegal to release all reptiles and amphibians originating outside of the state, native or not.

Despite this, online pond stores will sell tadpoles to all states where bullfrogs are native, apparently assuming that these states don't care about the release of bullfrog tadpoles. But some states ban it anyway, believing that bullfrog tadpoles can carry diseases.

I can still keep my captive red-eared slider outdoors, even though she isn't native, if the pond is enclosed to prevent escape. The same is applicable to bullfrog tadpoles. It isn't as easy to contain baby bullfrogs, though, when they want to escape.

 

[Wayfarin]

What would be the minimum pond size to attract a breeding pair of adult bullfrogs?

What's the smallest pond or pool that they would use for breeding and bringing up tadpoles?