Thermal gradients - good or bad?

[bladeblaster]

have touched on this in other posts, but thought I would give the subject a thread of its own, please feel free to discuss.

As we all know, reptiles are ectothermic, they take heat from their surroundings, rather than generating their own body heat (although most reptiles have some very small control over body temperature). However there are 2 sub-groups within this ectothermic bracket.

Stenothermal - Reptiles that accurately control their body temperature constantly within a few degrees.

Eurythermal - Reptiles that allow their body temperature to fluctuate to extremes.

Generally speaking, the more terrestrial the reptile the more Stenothermal.

In other words, and genealy speaking, most terrestrial snakes, only bask because they have to, they would prefer as stable a temperature as possible. So whilst to some degree, giving a large temperature gradient mimics what it would need to do in the wild, is it actually what the snake needs?

The optimum operating body temperature for a snake is the Prefered Optimum range, here is the prefered optimum range for a few commonly kept snakes, some might surprise you.

Boa Constrictor - 84 - 86
Royal - 84 - 86
GTP - 75 - 82
Carpet - 80 - 85
Corn - 77 - 84
Garter - 75 - 80

[Norm66]

Very interesting thought. It's something I've thought about ever since I read a few big breeders don't use heat in their cages but rather just heat their rooms and their snakes do fine.

I can see this getting fairly contentious because providing a gradient is such an established part of captive husbandry. I know my snakes go from side to side in their (gradient provided) tubs and sometimes feel warm and sometimes cool to the touch (though this is obviously subjective) but do they really require it or would they do fine in a constant temp?

I look forward to hearing people's opinions.

[red ink]

It would depend on what people would define as a thermal gradient.

A heat mat or a heat cord under a spot in an enclosure or a spot is not a thermal gradient it's a hot spot. In this case a terrestrial stenothermal specimen would probably be having a hard time of it where as a Eurythermal specimen would do fine in that set up.

An enclosure with a lamp on one spot controlled by a thermostat can have a thermal gradient but unless set up properly all it is really is an enclosure with a basking spot... One hot end and one cool end is not a gradient it's a temperature zoned differential in a small space.

IMO thermal gradient is dependant more on air temps rather than one hot side and one cool side in an enclosure.

The predominant snakes in the reptile hobby are nocturnal all pythons and boas are predominantly nocturnal so their thermal adaptation is actually attuned to air temps rather than a hot spot in an enclosure.

[bladeblaster]

I was refering to thermal gradient as dif in temps across the enclosure, so zonal temp differences as you have described it. I suppose it would also include varying night time temps etc as well.

[StudentoReptile]

I would think that for diurnal species more active and more likely to bask in direct sunlight would benefit more from a "zonal" thermal gradient set-up; i.e. species like garter snakes, Nerodia, racers, cribos/indigos sp., etc. These snakes, from what I understand, also have higher metabolisms.

I have spoken with other colubrid keepers, and a few have said they have better success with their animals just providing a universal ambient temperature. When offered a gradient (heat tape on one end), nearly all the snakes would stick to the cool end and bowl-wrap, or soak in their water bowls.

[shaunyboy]

i find all my carpets do great,in the thermal gradient i give them

cool end 76F TO 82F,hot end 84F to 88F,depending on the individual snakes needs

its ceramics i use,so they have good ambient air temps

imo,it gives them the choice,to go to a temp that suits their needs for that particular day

i have found they will use different parts of the tank when,my ambient room temperatures change,or during certain phases of the shedding proccess

imo,giving them different temperatures to choose from is important,because during shedding and digesting food etc their requirements differ

^^^^^
hope that all makes sense


cheers shaun:)

[red ink]

If we are going the heat up the whole room to a stable temp that provides the correct temperature requirements for the specimens to attain their PBT then I believe there would be no need for a thermal gradient within the enclosure.

The key thing to this is a stable temp over a large area i.e. the room as all heating for the ectothermic specimens is dependant on this.

A thermal gradient in the enclosure is needed due to one factor... unstable external ambient temperature. This is largely for the safety of the specimen rather than it achieving PBT.

If the ambient temps are unstable what happens when they get too high i.e. a hot summer day, hot ambient temps plus an internal heat source in an enclosure can cause the internal temps in the enclosure to go beyond the specimens health threshold and could result in a very nasty situation. How do we provide a safeguard to this scenario if we can not control the fluctuations of external ambient... create a safe haven within the enclosure where they can escape from the heat, a cool side (thermal/zonal temperature gradient).

Most of us can't create a stable ambient for a whole room so given that then I would have to take the stance that yes.. thermal gradients are good and in some cases where the ambient temps can fluctuate to extreme heat I would even say it's necessary and negligent not to have one.

[Terranaut]

I am expecting a gradient in my new JCP enclosure. But verticaly not horizontaly. I think this will be easier to achieve.

[red ink]

I am expecting a gradient in my new JCP enclosure. But verticaly not horizontaly. I think this will be easier to achieve.

It is definitely easier to achieve a vertical thermal gradient... I have a vertical thermal gradient in both my JCP enclosures.

[red ink]

i find all my carpets do great,in the thermal gradient i give them

cool end 76F TO 82F,hot end 84F to 88F,depending on the individual snakes needs

its ceramics i use,so they have good ambient air temps

imo,it gives them the choice,to go to a temp that suits their needs for that particular day

i have found they will use different parts of the tank when,my ambient room temperatures change,or during certain phases of the shedding proccess

imo,giving them different temperatures to choose from is important,because during shedding and digesting food etc their requirements differ

^^^^^
hope that all makes sense


cheers shaun:)

A thermal gradient is definitely needed in a DP enclosure as you know... I would hate to see what would happen to a DP in a one thermal zoned enclosure with the temperature constantly set for their optimum temperature range.

[bladeblaster]

i find all my carpets do great,in the thermal gradient i give them

cool end 76F TO 82F,hot end 84F to 88F,depending on the individual snakes needs

its ceramics i use,so they have good ambient air temps

imo,it gives them the choice,to go to a temp that suits their needs for that particular day

i have found they will use different parts of the tank when,my ambient room temperatures change,or during certain phases of the shedding proccess

imo,giving them different temperatures to choose from is important,because during shedding and digesting food etc their requirements differ

^^^^^
hope that all makes sense


cheers shaun:)

I am quite sure they all do great mate, as do mine with a thermal gradient within the viv. What I want to do is conduct an experiment to see if there is actually any difference between 2 snakes kept in these different ways, and over a period of many years to see if it actually could have an impact on lifespan.

If we are going the heat up the whole room to a stable temp that provides the correct temperature requirements for the specimens to attain their PBT then I believe there would be no need for a thermal gradient within the enclosure.

The key thing to this is a stable temp over a large area i.e. the room as all heating for the ectothermic specimens is dependant on this.

A thermal gradient in the enclosure is needed due to one factor... unstable external ambient temperature. This is largely for the safety of the specimen rather than it achieving PBT.

If the ambient temps are unstable what happens when they get too high i.e. a hot summer day, hot ambient temps plus an internal heat source in an enclosure can cause the internal temps in the enclosure to go beyond the specimens health threshold and could result in a very nasty situation. How do we provide a safeguard to this scenario if we can not control the fluctuations of external ambient... create a safe haven within the enclosure where they can escape from the heat, a cool side (thermal/zonal temperature gradient).

Most of us can't create a stable ambient for a whole room so given that then I would have to take the stance that yes.. thermal gradients are good and in some cases where the ambient temps can fluctuate to extreme heat I would even say it's necessary and negligent not to have one.

I suppose this does depend on where you live and what set up you have for your reptile room. My own reptile roon has a very stable temperature. What I am suggesting though is have the temperature control within the enclosure not just in the room.

A thermal gradient is definitely needed in a DP enclosure as you know... I would hate to see what would happen to a DP in a one thermal zoned enclosure with the temperature constantly set for their optimum temperature range.

Of course I have tried to use wording such as 'gerneral' and 'typically' as there will always be excpetions, and Diamond are the exception the the rule where pythons are concerned.

[jarich]

Using the terms 'reptile' or 'snake' in this thread makes the hypothesis essentially void though. This would have to be a very species specific situation. For instance, if it was a rain forest snake that lived under the canopy, which rarely has access to direct sunlight and temperature fluctuations, then it seems like a gradient wouldnt be that necessary. However, reptiles with access to direct sunlight or the effects of direct sunlight make use of, and I would say, need the gradient. Even nocturnal species are often found on the road, or on rocks that retain the heat of the sunlight for gaining extra heat.

The thing is, the gradient has to be within the parameters of what the reptile wants/needs, not just what you provided. A keeper who provides one side with heat tape and finds all their snakes wrapped around water bowls on the cool side? Obviously this is just a problem with having the hot side too hot. I would bet that if they dropped the temps, they might find that the snake used the entire enclosure. Which is the other reason why a gradient is good. There are too many people who do not pay close enough attention to the cues their animals are giving them. As Red Ink said, the gradient leaves room, not just for husbandry errors, but for the keeper to be able to see what the animal actually wants. If you provide a wide gradient, and find that it only uses part of that gradient, then adjust it accordingly.

[bladeblaster]

Even nocturnal species are often found on the road, or on rocks that retain the heat of the sunlight for gaining extra heat. .

but only because they have to?

[jarich]

Its a dangerous argument, in my opinion, to say that we are 'improving' on nature, when we do not understand the totality of the systems we are discussing. Sure its easy to use the argument that we improve on nature because we take away their predators, but what about beyond that simplicity? Does anyone understand the interplay of heat and enzymes well enough to say that thermal gradients arent necessary? Similarly, what about the lack of hormonal dynamics due to a total lack of thermal gradation? How does the seasonality of our day/night cycle effect this? What about the snakes own ability to regulate this. Do we somehow know better than they themselves? I have a hard time believing that any proponent of 'improvement' of nature understands these or the many other facets involved.

Its an interesting argument, and Id love to see your testing of this hypothesis over time, but Im skeptical about this for most reptiles, to say the least.

[Snakesitter]

Excellent point, Jarich. The arguments on diet are similiar: snakes, for example, often get a mixture of prey in the wild, not all rodents. And even that ignores what trace elements and chemicals may be entirelty absent in captivity.....

More on topic, I try to offer my Brazilians a gradient of 82F on the warm wide to 72F on the cool side...though during the summer heat the cool end is more like 76F during the day.

[Caylan]

Personally, I have my room heated to 80* and a few of the snakes have heat tape under them controlled by herpstats. But even with carpets on and off heat tape, they both have the same feeding response they've always had, it just takes a day longer to digest without the hot spot. Different snakes have different requirements, but there is no one way to keep a snake. They outlived the dino's for a reason yuh know :D

[exwizard]

...Different snakes have different requirements, but there is no one way to keep a snake... I like your thinking. :)

[bladeblaster]

Its a dangerous argument, in my opinion, to say that we are 'improving' on nature, when we do not understand the totality of the systems we are discussing. Sure its easy to use the argument that we improve on nature because we take away their predators, but what about beyond that simplicity? Does anyone understand the interplay of heat and enzymes well enough to say that thermal gradients arent necessary? Similarly, what about the lack of hormonal dynamics due to a total lack of thermal gradation? How does the seasonality of our day/night cycle effect this? What about the snakes own ability to regulate this. Do we somehow know better than they themselves? I have a hard time believing that any proponent of 'improvement' of nature understands these or the many other facets involved.

Its an interesting argument, and Id love to see your testing of this hypothesis over time, but Im skeptical about this for most reptiles, to say the least.

I like your thinking. :)

A very good and valid argument. Now don't get me wrong I am not trying to improve on nature, and neither am I suggesting people take this on as an alternative husbendry technique. As I have said, I don't know if its good or bad, I am just throwing it out there for discussion ;)

Clearly there are snakes that are so adapted and reliant on temperature cycles that you couldn't possibly even contemplate trying it with them. However it is no accident that the closer you get to the equator (most stable temperature on the planet) the bigger the snakes get.

I intend to use 2 sibling boa contrictors for the experiment. One kept with a cool end of 75 basking spot 90, with a night time drop of 3 - 5*, and one with a uniform temp of 85* day and night.

[Jlassiter]

I would think that for diurnal species more active and more likely to bask in direct sunlight would benefit more from a "zonal" thermal gradient set-up; i.e. species like garter snakes, Nerodia, racers, cribos/indigos sp., etc. These snakes, from what I understand, also have higher metabolisms.

I have spoken with other colubrid keepers, and a few have said they have better success with their animals just providing a universal ambient temperature. When offered a gradient (heat tape on one end), nearly all the snakes would stick to the cool end and bowl-wrap, or soak in their water bowls.


I beg to differ with the colubrid "keepers" you got your information from.
My past few decades' experience has been with kingsnakes....mainly those from the mexicana complex. When provided options such as hot, cold, damp, dry, dark, light (room lighting) and combinations of each a kingsnake can choose what it wants not what the keeper forces upon it.

The trick is to use deepened Aspen, a room temp of 72F and back-heat that holds around 85F to 90F instead of belly heat....At least it works best for me this way....

The Aspen will isolate the hot area in the back of the enclosure....Another thing that must be considered is the number/amount of ventilation holes. Or screen top coverage for aquarium keepers.....

Another optimal option is a tub of Sphagnum moss......The tub should be placed in a fashion so that it has a cool/damp and a warm/damp area......

In my opinion, providing Thermal regulation and humidity options is the optimal way to keep colubrids.....

Once all the options are provided a keeper then can learn from their snakes. If the snake is "bowl-wrapping" or always near the water bowl the humidity is wrong or the keeper is using a light that is drying the air and the snake. Colubrids need no lighting at all except for room lighting.

If a colubrid is on the cool end........FEED it!
It is conserving instead of metabolizing.......

My two cents....

[StudentoReptile]

I beg to differ with the colubrid "keepers" you got your information from.

Nothing wrong with that. Different strokes for different folks.

In my opinion, providing Thermal regulation and humidity options is the optimal way to keep colubrids.....

I didn't say one way was right over the other. Just sharing what others shared with me. These individuals have been breeding colubrids for many years as well, so I would generally assume they're not "noobs".

[shaunyboy]

i'm looking forward to details,of the progression of your boa experiement Terry

cheers shaun:)

[hellosugaree]

Not every snake has the same self-preferred temperature. Having a gradient allows them to choose their own temperature. Some snakes prefer to be a bit hotter or cooler.

[Jlassiter]

Nothing wrong with that. Different strokes for different folks.



I didn't say one way was right over the other. Just sharing what others shared with me. These individuals have been breeding colubrids for many years as well, so I would generally assume they're not "noobs".

Cool...I just wanted to share my opinion.....
There are certainly many ways to reach a common goal but I am one to believe in a certain way being optimal......

[bladeblaster]

Not every snake has the same self-preferred temperature. Having a gradient allows them to choose their own temperature. Some snakes prefer to be a bit hotter or cooler.

science would beg to differ on that.

How they achieve it differs, however the optimum operating temperature range for all royals (for example) is the same.

[bladeblaster]

I beg to differ with the colubrid "keepers" you got your information from.
My past few decades' experience has been with kingsnakes....mainly those from the mexicana complex. When provided options such as hot, cold, damp, dry, dark, light (room lighting) and combinations of each a kingsnake can choose what it wants not what the keeper forces upon it...

I like this method of keeping, and one reason I am edging towards ever smaller species, as you can easily create may microclimates within a realstic space. :D

[hellosugaree]

science would beg to differ on that.

How they achieve it differs, however the optimum operating temperature range for all royals (for example) is the same.

Please cite your references if you are invoking the good name of science. Also, optimum and preferred are two different things. A gradient allows the snake to pick it's own temperature and how it wishes to achieve it. You will find that snakes move around all the time to adjust their temperature even in an environment with a stable gradient. This would suggest that they don't prefer the same temperature 24 hours a day 365 days a year. Factors like digestion, day/night cycle, activity, etc would likely influence the area/temperature chosen by the snake.

[bladeblaster]

Please cite your references if you are invoking the good name of science. Also, optimum and preferred are two different things. A gradient allows the snake to pick it's own temperature and how it wishes to achieve it. You will find that snakes move around all the time to adjust their temperature even in an environment with a stable gradient. This would suggest that they don't prefer the same temperature 24 hours a day 365 days a year. Factors like digestion, day/night cycle, activity, etc would likely influence the area/temperature chosen by the snake.

How about Douglas Mader?

No what is shows is that they need to move around to maintain an optimum temperature, not that they want to move around. You are confusing survival instinct with choice.

[Caylan]

Honestly... I find your experiment unnecessary... People all over already keep boas in different ranges of temperatures, and I have seen many thriving boas kept in various conditions and enclosures. I think you are under estimating the adaptability of an individual snake, also the fact that they do in fact sometimes have preferences when it comes to their surroundings. I've done my own experiments with poor feeding ball pythons in regards to trying completely different enclosures for weeks at a time to see what they prefer to live in. So far I have had a lot of success with this technique, but I also have the resources available to do so. I have had had to start hatchling ball pythons at my own house(from work obviously) because they simply did not like the plain enclosures they were being offered there... I took it home and offered it a slightly more exotic enclosure, larger and warmer, and the snake started eating that week... after 8 months of assist feeding, a move helped a feeding response... odd right?? Well the snake is now back at work and I had to actually bring over the hide I had at home to get it to start eating again, it didn't like the plastic cave, it wanted my half log for some reason... Snakes do have preferences, and they can live in a variety of conditions and enclosures. Just please use whats best for the snake in question, not what just what you think it needs. Good luck with your experiment if you choose to continue with it, I would be curious the results as I just don't have much experience with young boa constrictors yet...

[shaunyboy]

Honestly... I find your experiment unnecessary... People all over already keep boas in different ranges of temperatures, and I have seen many thriving boas kept in various conditions and enclosures. I think you are under estimating the adaptability of an individual snake, also the fact that they do in fact sometimes have preferences when it comes to their surroundings. I've done my own experiments with poor feeding ball pythons in regards to trying completely different enclosures for weeks at a time to see what they prefer to live in. So far I have had a lot of success with this technique, but I also have the resources available to do so. I have had had to start hatchling ball pythons at my own house(from work obviously) because they simply did not like the plain enclosures they were being offered there... I took it home and offered it a slightly more exotic enclosure, larger and warmer, and the snake started eating that week... after 8 months of assist feeding, a move helped a feeding response... odd right?? Well the snake is now back at work and I had to actually bring over the hide I had at home to get it to start eating again, it didn't like the plastic cave, it wanted my half log for some reason... Snakes do have preferences, and they can live in a variety of conditions and enclosures. Just please use whats best for the snake in question, not what just what you think it needs. Good luck with your experiment if you choose to continue with it, I would be curious the results as I just don't have much experience with young boa constrictors yet...

Terry has a lot of experience with snakes mate,he wouldn't willingly cause any harm or take risks with them (not being cheeky)

he works with lots of different species and due to his enquisitive mind is always looking for herp related answers

Caylan,sorry if i've got the sentiments of your post wrong,i thought you may be " worried " that,Terry's some random guy doing experiments for the sake of it.

he know his snakes and works with one of the top morelia breeders in europe (imo the top morelia breeder outside australia)

my apologys if i got this wrong Caylan,i was just trying to allay any worrys you may have,about Terry's experiment mate

cheers shaun

[bladeblaster]

Honestly... I find your experiment unnecessary... People all over already keep boas in different ranges of temperatures, and I have seen many thriving boas kept in various conditions and enclosures. I think you are under estimating the adaptability of an individual snake, also the fact that they do in fact sometimes have preferences when it comes to their surroundings. I've done my own experiments with poor feeding ball pythons in regards to trying completely different enclosures for weeks at a time to see what they prefer to live in. So far I have had a lot of success with this technique, but I also have the resources available to do so. I have had had to start hatchling ball pythons at my own house(from work obviously) because they simply did not like the plain enclosures they were being offered there... I took it home and offered it a slightly more exotic enclosure, larger and warmer, and the snake started eating that week... after 8 months of assist feeding, a move helped a feeding response... odd right?? Well the snake is now back at work and I had to actually bring over the hide I had at home to get it to start eating again, it didn't like the plastic cave, it wanted my half log for some reason... Snakes do have preferences, and they can live in a variety of conditions and enclosures. Just please use whats best for the snake in question, not what just what you think it needs. Good luck with your experiment if you choose to continue with it, I would be curious the results as I just don't have much experience with young boa constrictors yet...

The welfare of the animal is paramount, if at any point during this experiment I felt that it was detrimental to the snake, then I would halt it immeadiately and that would form the conclusion of the experiment.

The idea is to use 2 as identical snakes as possible, pure locality brothers, in identical set ups, identical feedng regimes, with the only difference being the heat they get, and see if there is any notable difference in behaviour and/or growth.

I closely monitor the behaviour of all of my snakes as a matter of course, its the best and earliest indictor for any keeper that something is amiss.

Terry has a lot of experience with snakes mate,he wouldn't willingly cause any harm or take risks with them (not being cheeky)

he works with lots of different species and due to his enquisitive mind is always looking for herp related answers

Caylan,sorry if i've got the sentiments of your post wrong,i thought you may be " worried " that,Terry's some random guy doing experiments for the sake of it.

he know his snakes and works with one of the top morelia breeders in europe (imo the top morelia breeder outside australia)

my apologys if i got this wrong Caylan,i was just trying to allay any worrys you may have,about Terry's experiment mate

cheers shaun


Thanks Shaun ;)