Pond Frogs Didn't Survive

[JBtheExplorer]

Hello, I'm new here but figured I'd get straight to the point. I plan on adding an introduction eventually.

I had four frogs. Two Green Frogs, two Bull Frogs. They aren't technically "mine"; they're wild frogs that moved into my garden pond last summer. They stuck around all summer and through hibernation and now that my pond is thawed I was looking around for them. Sadly, I've found already found two of them dead and scooped them, and at this point I have to expect the other two to also be dead.

I want to prevent future frogs from ending up with the same fate. My pond is 3' deep. At the bottom there is a pile of hornwort and a couple of pots with plants in them. There is a little muck, but only what built up over the summer, not more than a half inch. Ice never got close to the bottom, and I kept a small hole open in the ice with a pond heater for gases to exit and oxygen to enter.

I can't figure out why they didn't survive, so I came here in hopes that you guys could help me figure out how to improve the chances of future frogs. One of the reasons I built my 400g pond is to attract wildlife like frogs, toads, birds, and insects, so the last thing I want to see is them dead because they called my pond their home.

Here's my pond last Fall.

[kueluck]

Sorry to hear they didn't make it over the winter. I don't have any experience in this but hope that one of the "experts" chimes in. Only thing I can think of is that the water PH might be off or some kind of toxin was in the water.

[flybyferns]

Hi,

I'm thinking....maybe they are still there ?
It's really early. What do you you think?

Lynn

[Mentat]

You mentioned in your other thread there were goldfish in the pond; did they survive Winter? Have you done any water tests (pH, ammonia, nitrites, nitrates)?

[JBtheExplorer]

You mentioned in your other thread there were goldfish in the pond; did they survive Winter? Have you done any water tests (pH, ammonia, nitrites, nitrates)?

I actually bring the goldfish indoors since the deepest part of the pond would be too crowded for 9 fish and 4 frogs to all try and hibernate in. The water was fine last year. haven't tested it this year. That will be done in late April/May once we get the pump running, debris cleaned out, do a 50% water change, and prepare to put the fish back in.

[Elldee]

I actually bring the goldfish indoors since the deepest part of the pond would be too crowded for 9 fish and 4 frogs to all try and hibernate in. The water was fine last year. haven't tested it this year. That will be done in late April/May once we get the pump running, debris cleaned out, do a 50% water change, and prepare to put the fish back in.

do frogs hibernate under water?

[JBtheExplorer]

do frogs hibernate under water?

Yes, most do.

[Heatheranne]

Just taking a guess, but I'm wondering if either the water was too warm to entirely slow down enough to hibernate, meaning they would need food, or too cold. At a depth of 4' they can survive if its underground.

Sorry they did not make it. I'm sure more will come. When winter comes kick them out of the pond and cover it. Once they know where water and bugs are they will likely continue to return.

[JBtheExplorer]

I'm sure more will come.

Funny you should say that. I've already got a new Green Frog hanging out. My pond has been taken out to put in a larger one, so he/she has been patiently waiting in part of my stream. It sat out all day today watching me work on digging its new home.

[Ted]

A frog doesn't dig far into the mud in the water or it will suffocate,they usually stay on top of it.depth doesn't matter either as frogs actually freeze in the winter.their body creates a type of anti freeze that keeps them from dying,all body functions slow down ..so it might be in the water...

[UncleChester]

I'll second Heather's advice. We have an artificial pond, also about 3' deep. In particularly long and cold winters, we'd have far too many dead frogs so we've taken to punting them all out in the fall. We'd relocate them to a much deeper and larger spring fed pond (~8' deep and 100' across) at the back of the property. Frogs always find the smaller artificial pond come spring time.

This was a really bad winter. At the large pond, I'd usually find one or two dead frogs around the perimeter when the ice starts to clear (no matter what, they're not all going to make it). It's cleared around the edge as of yesterday and I've found about a dozen Leopard frogs belly up so far.

A frog doesn't dig far into the mud in the water or it will suffocate,they usually stay on top of it.depth doesn't matter either as frogs actually freeze in the winter.their body creates a type of anti freeze that keeps them from dying,all body functions slow down ..so it might be in the water...

Only a handful of frogs have anti-freeze like protection, green frogs and bullfrogs are not among them. They can't handle freezing. Water is densest at about 4C, and the pond hibernating frogs rely on this relatively warm water sinking to the bottom of the pond for them to winter in.

[Ted]

bullfrog needs deeper water in the winter , but yes they produce a antifreeze in their bodies also..Their glucose raises higher to keep them from freezing..

[UncleChester]

bullfrog needs deeper water in the winter , but yes they produce a antifreeze in their bodies also..Their glucose raises higher to keep them from freezing..

Bullfrogs aren't considered freeze tolerant according to any papers I've read. For example, http://www.units.miamioh.edu/cryolab...tanzoLee99.pdf mentions:

"Arnong the ranids, freeze tolerance has been demonstrated only in the most terrestrial species, the wood frog (Rana sylvatica), although it is likely that Palearctic brown frogs with similar habits (e.g., Rana arvalis; Kuzmin 1995) are also freeze tolerant."

I'd love to see any references you have, it could be a matter of degrees of 'freeze tolerance' if bullfrogs produce some level of cryoprotectants.

[Ted]

I'm not an expert,I went to google and typed in "do bullfrogs freeze in the winter?"..

[UncleChester]

I'm not an expert,I went to google and typed in "do bullfrogs freeze in the winter?"..

I'm by no means an expert either. I'm always up for learning something new and open to the possibility that I'm way wrong about just about anything.

I looked at the first couple of results from that google search and neither mention bullfrogs being freeze-tolerant. The first one How do frogs survive winter? Why don't they freeze to death? - Scientific American does mention the usual anti-freeze producing suspects Wood Frogs and Spring Peepers, the second just talks about Wood Frogs. Was there another link you found?

[Ted]

I'm kind of uncomfortable here,,I don't want to get in over my head,ok?..but what I really typed in was "does a bullfrog freeze?"...I found it on opinicon.wordpress....opinicon natural history..just below the graph but right above "conservation status"..

[UncleChester]

Sorry, I'm not trying to make you uncomfortable- we're just talking about some frog biology.

It never hurts to have the links you read on standby for when someone asks for more detail though. It looks like this is the one you had found: American bullfrog / Ouaouaron | Opinicon Natural History They mention that Bullfrogs aren't considered 'freeze tolerant', but have a few adaptations to help survive the cold.

The bit about higher glucose is interesting, and the paper referenced is freely available online Seasonal changes in the cardiovascular, respiratory and metabolic responses to temperature and hypoxia in the bullfrog rana catesbeiana Increased glucose doesn't mean they can handle freezing, or more importantly the extended periods of freezing that a few other species are known to take. The paper I linked to earlier was about Northern Cricket Frogs who produce large amounts of glucose when it gets cold but are decidedly incapable of taking much in the way of freezing. It would be interesting to know just what temperatures bullfrogs can handle and for how long, but honestly these kinds of studies are always a little depressing from the participants point of view.

Anyways, thanks for pointing me to the Opinicon blog, it has plenty of interesting stuff on it as well as piles of references.

[Ted]

Anything that survives the cold where I live has my respect..lol,the participants..yeah,they always have the last say,,actually this has been really great ,so thank you

[Heatheranne]

Remember, "Bullies" also eat a lot in the fall to fatten up. They are pretty tough.

Well, unless you're Heather's big baby "Bully", who is spoiled and warm all winter .

[JBtheExplorer]

Bullfrogs wont survive being frozen in ice, but they can survive in very cold water.