Brumation / Hibernation

[codie]

I guess this is as good a place as any for this discussion.
First let me ask for leniency if this topic is old or settled. Forgive my ignorance.
Typically we assume reptile "hibernation" is an attempt to stay warm during inhospitable weather. And to a degree that would be true especially in truly lethal conditions. But are all reptiles seeking the HIGHEST temperature available? In many other animals, (notably Bats) hibernation means finding the COLDEST tolerable temperature. Hibernation is not just avoiding dangerous cold, but also serves as away to conserve energy whey food resources may be limited or completely unavailable. Low body temperature equals low metabolic cost. It would seem to only make good biological sense to spend the winter as COLD as possible without freezing rather than seek out the WARMEST refuges available and burn energy when it least obtainable.
I am not suggesting that keepers of reptiles buy refrigerators for their herps. It has obviously been demonstrated that most reptiles do not REQUIRE massive cooldowns. But this is an artificial environment and animals may respond artificially to certain conditions.
I am just curious if anyone has explored how wild reptiles actually respond to the onset of inclement weather.

 

[hotlips]

I guess this is as good a place as any for this discussion.
First let me ask for leniency if this topic is old or settled. Forgive my ignorance.
Typically we assume reptile "hibernation" is an attempt to stay warm during inhospitable weather. And to a degree that would be true especially in truly lethal conditions. But are all reptiles seeking the HIGHEST temperature available? In many other animals, (notably Bats) hibernation means finding the COLDEST tolerable temperature. Hibernation is not just avoiding dangerous cold, but also serves as away to conserve energy whey food resources may be limited or completely unavailable. Low body temperature equals low metabolic cost. It would seem to only make good biological sense to spend the winter as COLD as possible without freezing rather than seek out the WARMEST refuges available and burn energy when it least obtainable.
I am not suggesting that keepers of reptiles buy refrigerators for their herps. It has obviously been demonstrated that most reptiles do not REQUIRE massive cooldowns. But this is an artificial environment and animals may respond artificially to certain conditions.
I am just curious if anyone has explored how wild reptiles actually respond to the onset of inclement weather.

Our reptiles are not trying to "stay warm" during hibernation, they're trying to stay alive with temperatures too cold for them to function normally. In doing so, they're conserving body weight while fasting but also the cool down is essential for maximum reproductive fertility. They instinctively know to stop eating when the temperatures fall & days get shorter, so as not to be "caught" with food in their digestive tract that would then spoil when they're too cold to digest it, causing them a reduced likelihood of survival. I think it's pretty amazing the way they can survive such adversity.

 

[Helenthereef]

I am keeping my Candoia bibroni bibroni (Fiji boas) in their native country and in natural conditions and temperatures.

In our winter months (roughly July to September) the males stop eating completely, but they are not inactive - in fact it's the opposite, as it is also their mating season and they spend a LOT of time roaming around their tank trying to get to the females.

On the other hand, the females reduce their intake but do not stop feeding, yet are less active than the non-feeding males.

So I suppose I am suggesting (in this species at least) that maybe the males want to be lean and mean to travel far and find the females, whilst the females need to conserve energy and food supplies in order to support pregnancy.

Just guesswork....

 

[codie]

Hibernation

I guess I didn’t make myself clear in my original post.
Reptiles have obviously evolved to adapt to include cool downs in their lifestyles, often to the point of requiring them. And that in itself is amazing. It just wasn’t my question.
Imagine yourself to be a Eastern garter snake in northern Illinois. Winter is approaching and it is imperative to find shelter from the coming sub-freezing to sub-zero temperatures. Suppose you have access to various refuges that provide a range of temperatures from barely above freezing to nominally below normal active temperature. Do you choose to stay as WARM as possible where danger from the cold is minimal yet metabolism stays high and you risk starving to death before spring arrives? Or do you choose to stay as COOL as possible where a lowered metabolism allows you to survive longer periods of fasting, but the risk of being exposed to lethal temperatures is greater? Remember that winter may last four months or more. That is a long time when energy reserves are only being depleted and virtually never replenished.
Both methods seem to be valid means of survival. But which one is more correct in nature? Or is the answer more complicated than that?
As I stated originally, some bats choose to stay as cold as possible to conserve energy. That is their strategy for survival. That is why some bat caves are barred from winter visitors. One or two disturbances per winter may cause a bat to burn so much energy that it could starve to death before spring. Bats and snakes are two completely different animals, but they are both facing the same threats to survival. Is it possible that their solutions are similar?
(By the way, I am aware that snakes and bats are not making those choices consciously. They are simply following the dictates of their instincts and lifestyles. I framed the question the way I did to (hopefully) make my question more clear.)
Unfortunately, captive care experiences do not really address these question as the animals are not responding to a natural environment. Captives often enter brumation with significantly greater fat reserves than they would in nature. They are are rarely exposed to a wide range of cool temperatures. ( I fully understand that. I wouldn’t risk my reptiles future with exposure to extreme temperatures if I know a minimal drop in temperature is sufficient to achieve the desired results.) Safe and secure “hibernacula” are provided for them. The animals may benefit from the increased security of captivity, but it doesn’t necessarily reflect nature.
I realize this may have little bearing on how we treat our animals. That is isn’t the question. This is just kind of a thought experiment. Reptiles have evolved to cope with a wide range of environments - some of them very extreme. Consider my example...garter snakes can survive in Canada where dealing with cold is a way of life, as well as Florida where frosts are rare and temporary. How they manage to do that is pretty amazing as well.
By the way, may I pose a another related question? Could an Eastern Garter snake from sub-tropical Florida be transplanted to northern Illinois given the proper conditions and conditioning? It has been shown that Burmese pythons are unable to “learn” to hibernate - one of the factors preventing their spread out of southern Florida. But can the same be said about a reptile that has very close relatives in northern climates? It would seem that a north to south transition would be easily accomplished but not south to north. Are instincts based on local conditions deeply enough ingrained to prevent such drastic change?
More food for thought...

 

[hotlips]

Many snakes are known to return to the same place for "hibernation" (or brumation) & surely they do not know in advance what temperatures the winter will actually bring, so I fail to see how they could be making any real choices about the matter. They rely on instincts to survive, & don't travel that far from where their lives started. Any snakes deliberately placed in far off areas have only a remote chance of surviving, but that's not entirely because they'd be in a new climate...even a snake that is relocated in their proper area but in territory unfamiliar to them stands a huge chance of non-survival simply because they must learn their way around by scent, feel & luck more than by vision. Snakes
in captivity are known to have poor survival even when their temperatures are only off by a modest amount...so I think that's your answer: don't mess with "mother nature".

 

[Socratic Monologue]

Could an Eastern Garter snake from sub-tropical Florida be transplanted to northern Illinois given the proper conditions and conditioning?

Answering this would probably require academic study of the species (and perhaps of certain groups within the species); there's likely no general, cross-species answer. Consider trees: you can transplant or grow from seed any white pine (P. strobus) anywhere in suitable habitat. But Eastern Redbud (Cercis candadensis) will grow in certain parts of its range only from local stock; that is, you can't grow Redbud here in central WI from seed or transplants from, say, Missouri. Non local strains don't survive winter here.

So I don't think you can extrapolate from Asian Pythons to garters, and certainly not to reptiles in general, nor can you likely make any general claims about reptile hibernation.

There's a little bit of anecdotal evidence in the hobby for some of your questions. Mountain kingsnake keepers report better breeding results from males hibernated at the low end of the temp range. Hibernating at temps in the warmer end of an animal's tolerable range is thought to lead to excessive weight loss and susceptibility to opportunistic infection.

Your questions are quite interesting; hopefully someone can chime in here with links to academic papers. There's likely a lot of data on some aspects of these issues (e.g. rattlesnake hibernation).

 

[codie]

Brumation

Thanks for the response, Socratic Monologue,
That's more along the lines of the answers I was seeking. I know I may not get definitive answers, but I did want people to think. Discussions are good for the brain even if they don't always culminate in results.
Your comments on trees were new to me, and I appreciate your input. I was also unaware of the research done on kingsnakes.
So there! I learned something! Good for me!
Again, thanks for the info.

 

[Socratic Monologue]

You're welcome, John.

I don't think what's believed in the hobby about mountain kings -- that males are better breeders when hibernated cool -- is known from (empirical) research; it is simply 'the word on the street', so to speak. I thought I recall Bob Applegate writing something along these lines years ago, based only on his results in his collection in the early days of snake breeding.

If it is based on academic research, it is likely listed here; Bob Hansen maintains an epic bibliography, though only on L. mexicana and related species:

http://www.sierraherps.com/bibliography

A Google Scholar search turns up a couple interesting looking papers; some you can read the full text with only a free JSTOR account:

https://scholar.google.com/scholar?start=10&q=reptile+hibernation&hl=en&as_sdt=0,50

More specific search terms would likely get you even better results.

I don't know where you are in IL, but a good academic library would have copies of a lot of the relevant journals, and likely a photocopier that accepts credit cards

 

[HiddenHerps]

I can add a personal observation. I grow a large Potager Garden and every fall I use my chicken's old substrate as a combo mulch and fertilizer. The first year I tried to take it off very early spring but found several toads beneath it. I was shocked to find them so close to the surface. Why were they not underground? After closer inspection I saw there were holes near them thqt went deeper down into the soil. I asked a biologist I know and she said that they were likely to be using the heat from the litter decomposition to keep warm and thermoregulating by traveling back ans forth. I now leave my litter on untill the spring rains start.

 

[HiddenHerps]

Please excuse typos I can't edit.

 

[codie]

Hi Lauren,
I appreciate the input.
While I'm not saying you're wrong, let me point out that Wood Frogs will use the thinnest cover in winter and allow themselves to freeze solid. They are then capable of "re-animating" in spring. In this case the frogs are certainly not trying to stay warm, but are in fact allowing themselves to reach extremely cold temps. So the matter can be fairly complicated. So in your case are the toads "trying to stay warm", or are they "trying to stay cold"?
Some turtles seek out water that won't freeze but is very cold and allow their metabolism to slow down so much that they do without normal breathing for the duration of winter. (There may some gas exchange in their throats and/or cloacae, but no lung respiration.)
I am glad to see people thinking. That is always a good thing.
So, Lauren, I don't know if you're right, but keep exercising your brain.

 

[Socratic Monologue]

Bufo thermoregulate during hibernation, says empirical science in agreement with Lauren:

https://www.jstor.org/stable/3682705?seq=1#page_scan_tab_contents

No offense, but cross-species inference is pure speculation, and pales in comparison to scientific research.

 

[codie]

John,
Of course you’re correct that cross species inferences are speculative, just as you are right that true scientific research is the preferred path to discovery.
But often speculation is the driving force to initiating research. Certainly an idea must exist before investigation can confirm or discount that thought. A question must be asked before an answer can be given. Even the most empirical of researchers must first begin with a question. Darwin “speculated” about evolution and then spent decades trying to scientifically prove it, That’s, in part, the point of my initiating this discussion. I have questions and I’m looking for answers.
Also cross species comparisons are not necessarily invalid. Animals facing similar strong evolutionary pressures can share common solutions. Look at hibernation/brumation itself. That response to weather extremes has developed in a wide range of unrelated animals. The mechanisms for doing so may not be identical in all cases, but the similarities exist. Perhaps dealing with inclement weather while simultaneously losing one’s food source has limited options (e.g. hibernation or migration).
Many animals fly and they do so in widely different ways with widely different evolutionary histories. But how they do so is restricted by laws of physics. As a result, there are certain characteristics that they must share. That fact invites comparison even though we may be comparing an albatross to a little brown bat to a honey bee.
Again, I’m not saying that I’m right or that anyone else is wrong. I certainly don’t have the credentials or the experience for that. And, yes, I am speculating. But that isn’t automatically a bad thing. It may open one’s eyes to different way of seeing common things.

And to Lauren,
If I seemed to imply you were wrong, I apologize. I brought up the info about Wood Frogs only to suggest that the similar observations can result in different conclusions. If the research John cited does in fact ( and I have doubt that it does) support you then GREAT! I have learned something! Thank you. That alone, I my mind, validates the opening of this discussion.