How We Heat Our Tortoises

[Tom]

When my new sulcata babies hatch out this spring, I'm going to raise some of them in a large closed tub. It will be like a giant humid incubation chamber. I'm trying to find a way to heat it from below instead of using basking lights. This leads me to the debatable question. For many years, I've been a proponent of over head heat bulbs for reptiles. However, I've seen many situations were tortoises and other animals are perfectly healthy and doing well in a warm room, but with no overhead heat. There is no desiccating "basking spot" in nature. You are either in the sun or you are not. I've always told people and been told by people that reptiles NEED a thermal gradient within their enclosure so that they can regulate their own temp. Yet the ones living with just a warm-ish background temp seem to thrive and do well. Richard Fife starts his babies this way, for example. Many redfoot enclosures are somewhat like this too.

So my idea is too set up a thermostat on a timer and heat the whole enclosure up to 90-95 during the day and then let it cool to the room temp of 80 at night. I'll give them some flourescent light to see by during the day, but all their heat will be more "environmental" instead of in just one spot. Isn't this closer to nature? Either its a warm day outside, or its not.

The goal is to NOT dry out the air and their shells while they are little babies. I would keep them this way until they hit around 6" or so. They would still get daily sunning sessions for an hour or two also.

What do y'all think?

 

[PeanutbuttER]

I think it's a promising idea and am excited to see the eventual experiment that arises out of it.

 

[Yvonne G]

What about UVB?

 

[Balboa]

No surprise, I think you have something there Tom. We're both of a like mind on the current state of Tortoise enclosures.

I'm nervous about leaving NO escape. In nature there is the possibility for a tort to either dig into a cool spot, a burrow, under a shade tree whatever, where it will be substantially cooler than in the open.

I guess I'm just planning on taking a more cautious approach and still providing both warm and cool spots but hope to manage non-dessicating humidity levels in the warmer spots. That may, however, turn out to be unnecessary.

 

[Tom]

What about UVB?

2nd to last sentence in post #1.

 

[Madkins007]

I'm a proponent for thermoclines, and only in favor of basking sites as one way to accomplish this. My thinking is that tortoises are masters of the microclimate- varying temps and humidities for what they are looking for. Even in an 87F rainforest, there are microclimates down to the upper 60's. We know they often seek warmth to digest and fight infections, and seek cooler temps for hiding, etc.

I also suspect that our formulas for heat and humidity do not take the 'feels like' factor into account- high humidity at 90F probably feels a lot different to them than a drier 90F does- just as it does to us. Offering options would be a way to deal with this even though we may not have a real answer yet.

Having said that, I also think the thermogradient has to fit the habitat- there is no reason for a 20 degree variation in a smaller habitat like you are talking about, and overall I think you may be on to something.

 

[Tom]

I don't think the word "thermocline" correctly describes what we are talking about, but I get what you mean. Since I've seen so many torts living in warm rooms with no other heat or basking source, I'm still inclined to think it works just fine for them. It goes against my usual way of thinking too.

I don't think humidity matters to reptiles as far as how hot it "feels". It feels hotter to us, and other mammals, because all the moisture in the air inhibits our evaporative cooling system. 90 is still 90, regardless of the humidity percentage.

I've heard many people reference the 85 degree mark as the minimum needed for torts to digest their food and get all their systems up and running. Thats why I figure if I get them up to 90-95, they should be able to function just fine. Also, whenever I temp gun them when they are out in the sun they as usually 93-97, regardless of wether the outside temp is 65 or 95.

 

[jackrat]

I am one of the ones who simply heats the whole room.I use an oil filled radiator with a digital thermostat and run 2 vaporizors.It stays about 86 degrees and humid like a jungle.The redfoots seem to like it-no problems so far

 

[-ryan-]

You know, this is something I have been thinking about in a slightly different way for a while now. Mostly I have been considering the fact that, as incandescent and halogen bulbs (my preferred cheapskate heating/lighting method) are phased out in favor of more energy efficient bulbs, they will become more expensive and therefore it will start to make more sense to invest in a long-term heating system, rather than bulbs and fixtures that eventually go bad and are replaced.

I have actually been considering utilizing suitably sized radiant heating panels on thermostats. I figure I could mount them from the ceilings of the enclosures, and perhaps even put them on a board held up by chains so that I can lower them down close to the animals. Then just use fluorescent or compact fluorescent bulbs (not the uvb ones) for ambient light. Have the setups run on a thermostat, and it would probably be a more efficient system than using my 45 watt halogen bulbs. It's something I think I will continue to look into. The start-up costs are much more expensive, but quality heat panels should last a decade or more.

I have also been considering using a small radiant heat panel with my red foot to try to produce some ambient heat, and then a pig blanket for "basking", but the problem is that he is in a vision enclosure so the pig blanket won't lay flat, and I would be concerned about mulch getting under or on top of it and becoming a fire hazard.

Just some things I have been contemplating for a while. I'm excited to see what you discover with your experiment.

 

[John]

heres my plan,and its based on the materials and components available too me.im gonna use a small commercial type hot water heater add a pump and pipe coils for radiant heat.then im gonna go with an old idea for humidity and take a second hot water heater and cut the top off this will have a water make up and just boil water into the air controlled by a humidistat.i firmly believe controlling the atmosphere in the room as opposed to each snclosure is the way too go especialy due too the fact that the animals i keep all have similar requirements the only thing i don't like is the timers i prefer too use photocells

 

[kbaker]

Tom-
What's the determining factors of success? It sounds like you are trying to cut back on the amount of work it takes to keep them hydrated (which is always good). I believe the gradient is important, but you talk about the hot spot being too hot and they dry out the tortoise. Hot spots are suppose to be hot to help give the gradient of heat and in nature, there are plenty of hot areas so they do have access to them when desired. If the tortoise can't move from the hot spot to other temps, it is bad. I don't think you this is the case for you and I don't think they are sitting under the hot spot willfully overheating and drying out.

It's hard to keep this scope small because of the different types of tortoise (Sulcatas are different from Redfoots) and captive vs. natural conditions. I look at our tortoises as captive (for lack of a better term) and try to find ways to improve keeping them that way. I know Tom likes to (go off the deep end...LOL) move toward keeping them closer to natural conditions.

One other facter here is whether the pens/cages are enclosed/covered. If the tortoise home is contained, there is less air movement which reduces the 'beef jerk' effect. The larger the cage and the more open the pen, the harder it is to stop the 'beef jerking' effect. And depending on the room's temps and the cage being contained, the moister can condense on the sides of the cage which means that moister is being pulled from somewhere.

In the end, I think many factors need to be considered and a unique balance needs to be applied and re-applied for the best captive environment. The tortoise will tell/show you what you need to know.

Merry Christmas-

 

[Madkins007]

Tom- you are right, the word I am looking for is not thermocline (thermal barrier/layer in bodies of water), but danged if I can remember the right term! Thermograde? That isn't even in the dictionary. Dang again!

I'm not so sure I would dismiss the idea that humidity has little effect on what the temps feel like. Even though reptilian skin is waterproof, there is still some vapor loss (more like Gore-Tex than plastic), which would go faster in drier weather and it would affect the dermal cells 'plumping up' with moisture. The more humid air also carries more heat energy. At least, this is my pet theory why keepers report different behaviors at the same temps!

I DO think you are on to something, and I would bet that even in an 'incubator' style habitat in a warm room, you'll still get plenty of microclimates as the various elements interact.

 

[Balboa]

Kbaker, the problem is that a "hotspot" produced as a focal point of radiant heat has CONSIDERABLY lower relative humidity than the cooler air around it, so even if the enclosure wide humidity isn't bad, that hotspot is a jerky maker, and far too often torts seem to like to hang out there.

Mark has an interesting point there. Exactly the reason humid air feels hotter than dry air of the same temp is it actually packs more thermal energy. How this effects tortoises... I need to think more on.

 

[Maggie Cummings]

Bob's shed is a constant 89 degrees. His basking spot under his Trex bulb is 110 degrees. He never uses his basking spot anymore. When I go into his shed, no matter when or how often, he is sprawled out in the typical basking position in the middle of the room. Same with Queenie. Neither use their basking spot any more. I run a humidifier all day. I don't know what this means, just thought I would bring it up as the it's not necessary to have a hot spot.

 

[kbaker]

Kbaker, the problem is that a "hotspot" produced as a focal point of radiant heat has CONSIDERABLY lower relative humidity than the cooler air around it, so even if the enclosure wide humidity isn't bad, that hotspot is a jerky maker, and far too often torts seem to like to hang out there.

Mark has an interesting point there. Exactly the reason humid air feels hotter than dry air of the same temp is it actually packs more thermal energy. How this effects tortoises... I need to think more on.

First let me say when it comes to discussing things, forums truely suck...if we all could be in the same room and talk, it would be fantastic!!

Just like the 'wet and/or humidity' myth with tortoises/reptiles, there are others that need to be over come. Whether its a six sided glass box or wood box, it's all the same. So using 'fish tanks' should not be voodoo.

"Hot spots" should be better understood. Like you should use a flood lite over a spot lite. Yes, if you have an over sized bulb in a cold room - you do not get the desired results. Don't be afraid to use multiple bulbs. And another myth of keeping the bulb shining straight down needs to change. Putting them on angles give you so much more control of heating and basking. In the end, tortoises need a hotspot, but you need to do it smart like so it does more good than bad.

I have given examples of humidity before with little effect. 'It's a dry heat' we have all heard before. Yes, it makes a difference. Up to 110 degrees F. After that, you feel every degree. If you live in the Midwest you know the end of summer is super humid. Whether it's 80F or 95F, you are dripping in sweat and it's uncomfortable - muggy. It feels different because it is different!!

As for reptiles having waterproof skin...its meant differently than stated because that is obviously not true.

There is a lot of info that people know and ignore. They are happy in their own world and even if they told anyone of the "Secrets", people don't listen or understand. That's the toughest part of wanting to share information.

 

[kbaker]

Bob's shed is a constant 89 degrees. His basking spot under his Trex bulb is 110 degrees. He never uses his basking spot anymore. When I go into his shed, no matter when or how often, he is sprawled out in the typical basking position in the middle of the room. Same with Queenie. Neither use their basking spot any more. I run a humidifier all day. I don't know what this means, just thought I would bring it up as the it's not necessary to have a hot spot.

There are a few missing pieces of the puzzle here. I don't recall everything about Bob and where you are. Can we assume if Bob's in a shed, he has access outside the shed? Are you in Maine or Texas? Is it Spring, Summer, Fall or Winter? If housed outside in a warm enough location, the Sun is the hotspot. I say a hotspot is required, but did not say they should use it all the time or a high percentage of time. In general, tortoises need a hotspot to warm up in the morning, help digest food, fight infection and reproduction. A tortoise can survive long term with out a hotspot, but it's those times when they need it, it hurts if they don't have it. Also, a large tortoise will retain/gain/release heat differently than a small one.

89F is plenty warm and if Bob uses his hotspot, it would not be for very long. Tortoises really don't bask like turtles or other reptiles, but they still require to at times. With the hotspot at 110F, is it air temps or did you prop a 2X4 at Bob's shell height under the bulb for an hour and use a temp gun for surface temps?

I don't expect anwers to all the questions, but the point I am making is that a lot of factors are at play and they all have to be considered. Does Bob's shed have much ventilation? Is it insulated well? Are the walls and floor cold to the touch? Is there dirt on the floor?
Everyone's condition is different and there is not a formula that applies to all. You have to adjust things for a proper balance and then re-adjust again when the factors change. You have to consider the value of each factor...like if you buy and feed certain greens from the same place. Your tortoise may be doing great and then the growing season changes and the store gets their greens some where else and the nutritional values are sure to change.

If you live in warmer climates, I can see were someone might lean towards not having a hotspot. If you live where it gets cold, your tortoise's health may depend on having access to a hotspot. And for those who lean towards natural conditions, the Sun gives very hot hotspots and it is there when they need it.

P.S. I saw Oregon after I posted, but you still see what I mean, right?

 

[Madkins007]

As for reptiles having waterproof skin...its meant differently than stated because that is obviously not true.

I was confused by this comment. The best research I can find confirms that water does not pass from outside to inside through a chelonian's skin- it is waterproof.

Water vapor can, however, pass from the inside to the outside. That is not a violation of the 'waterproof skin' bit as water vapor behaves a bit differently than water when it comes to permeable membranes.

I can't find any good research on the effects of humidity/moisture penetrating from outside to inside, but I would also assume the pressure inside the skin would be high enough to minimize this.

 

[kbaker]

I was confused by this comment. The best research I can find confirms that water does not pass from outside to inside through a chelonian's skin- it is waterproof.

Water vapor can, however, pass from the inside to the outside. That is not a violation of the 'waterproof skin' bit as water vapor behaves a bit differently than water when it comes to permeable membranes.

I can't find any good research on the effects of humidity/moisture penetrating from outside to inside, but I would also assume the pressure inside the skin would be high enough to minimize this.

I was thinking waterproof as both direction...which may not be the excepted definition so you are probably right.

This does go in the direction of reptiles can dehydrate from water moving outward through the skin. Excess external moister and/or humidity does not rehydrate the reptile. The important thing here is that a reptile should be well hydrated and the excess external moister and/or humidity reduces the speed of dehydration throught the skin.