Tortoises & Body Temp

[Yourlocalpoet]

Hello TFO!
It's been an absolute age since I last graced the forum and all sorts have changed! Looks good
So summer has arrived in the UK, (finally) which means Esmeralda gets giddy about constant outside playtime (yay) and it's also prompted a question I hope some knowledgable person may be able to answer.
Last night I was sat watching her stomp around the garden, (it was 7.30pm and 11C, 52F) and she'd been out in that temp for a few hours at least, full of beans, no sign of slowing down.
Thing is, I was freezing! It made me wonder, how long can tortoises retain their desired body temp for when it's not that warm outside? Or how quickly do they lose heat when not exposed to a heat source?

I mean, I was cold so I wanted to bring her inside but she was still stomping around like it was midday!




Anyone remember this face?

 

[Tom]

I remember you AND your tortoise! Hi!

There is no set answer for this. It has to do with ground temps, which are warmer after a sunny day, wind, humidity, dampness, but most of all, I think it has to do with motivation. Yvonne and I both noted how our sulcatas come out in the rain on cold nights. They really want to be in that water and so they are able to move about just fine, albeit a bit slower as they cool. Many times I've had females out laying eggs on a January night with temps in the 30s. They can still get about when they want to even when temps drop.

Personally I don't like them out in temps that cold. I lock them up at night now and I always put a heat source over those laying females. Just because they might want it, doesn't mean its good for them.

 

[Yvonne G]

The bigger tortoises keep their inner core temperatures longer than the smaller ones do. I read something a while ago about how digesting food warms up the interior of a tortoise too. I wish I had kept track of that article because it helps one understand 'cold-blooded'.

And, might I say, That is one beautiful-looking leopard tortoise. What a fine job you've done on raising her up smooth.

 

[Grandpa Turtle 144]

From what I understand is a torts belly is like a compost pile ( a compost pile can reach180 degrees ) and the black spots on the shell helps raise the body temps .


Sent from my iPhone using TortForum

 

[Yourlocalpoet]

Hi Tom and Yvonne. Thanks for your replies - awesome to see you both still on the front line of all things tortoise.

I'd love to know the ins and outs of being cold blooded, it's fascinating and also confusing and I can never find any decent literature on the topic, especially for tortoises.

It's interesting that you say 'want' Tom, as that suggests reptiles have an interest in continued life, thus a concept of themselves as continuing subjects of experience, which I'd like to believe they do, but I think that's another discussion.

However, I suppose my question was also, is she clever enough to realise when she needs to go back to a heat source, which kind of would make the aforementioned relevant.

Interesting all the same.

 

[Yvonne G]

The bigger tortoises certainly are (smart enough to go in when they get cold), however the babies cool down so quickly (or heat up, if they're on a heating pad) that they don't realize they must move. Maggie (Maggie3fan) has pictures of Bob (larger sulcata) out in the snow...making all kinds of tortoise tracks. I used to have pictures of my Dudley with frost on his back, but I can't find them anymore.

 

[Maggie Cummings]

I do believe an older bigger tortoise stays out in the cold longer and Bob especially knows when to go in and get under his light. I open his doggie door rain and snow and he has never shown any URTI symptoms...I can't say that for some of my smaller tortoises. One would get a bubbly nose when the temp in the house changed some.
You need to get to know Esmeralda herself and discover if she's smart enough to know to go in when she gets cold. It's kinda trial and error when they are smaller...she's pretty...

 

[Yourlocalpoet]

I do believe an older bigger tortoise stays out in the cold longer and Bob especially knows when to go in and get under his light. I open his doggie door rain and snow and he has never shown any URTI symptoms...I can't say that for some of my smaller tortoises. One would get a bubbly nose when the temp in the house changed some.
You need to get to know Esmeralda herself and discover if she's smart enough to know to go in when she gets cold. It's kinda trial and error when they are smaller...she's pretty...

Thanks Maggie. I know our Esmeralda well, people who say tortoises don't have personalities obviously have never owned one!

When she's had enough or cold she retreats to her favourite corner and parks up and then just looks at me like, 'right, I'm ready to go inside'
(as I live in a temperamental and mostly cold climate she can't live outdoors permanently).

I was just asking more generally about their tolerance and self awareness of their environment I suppose.

How is Bob? It's been about 2 years since I was last here!

 

[N2TORTS]

The regulation of internal body temperature of reptiles/tortoises is produced by the external absorption of heat. Thus, reptiles are ectothermic. Unlike endothermic creatures "Humans", which must use calories from food to regulate body temperature, In general reptiles/tortoises don't require much food to maintain body temperature and survive. It's all about the surrounding temps ,both air born and soil retention and heat producing factors such as decay , that another member pointed out.

 

[N2TORTS]

I remember you AND your tortoise! Hi!

There is no set answer for this. It has to do with ground temps, which are warmer after a sunny day, wind, humidity, dampness, but most of all, I think it has to do with motivation. Yvonne and I both noted how our sulcatas come out in the rain on cold nights. They really want to be in that water and so they are able to move about just fine, albeit a bit slower as they cool. Many times I've had females out laying eggs on a January night with temps in the 30s. They can still get about when they want to even when temps drop.

Personally I don't like them out in temps that cold. I lock them up at night now and I always put a heat source over those laying females. Just because they might want it, doesn't mean its good for them.

*Excellent answer Mr. Tom!

 

[Tom]

However, I suppose my question was also, is she clever enough to realise when she needs to go back to a heat source, which kind of would make the aforementioned relevant.

In my experience, no. they are not "clever" enough. Sometimes they do make their way back to their heat source like Maggie's Bob and most of mine after they are "trained" to retire to their boxes, but often they don't. In the wild where they evolved they are equipped to deal with whatever the weather throws at them. When we move them to a different part of the world, they don't necessarily have the survival mechanisms that tell them what to do. For example: When I move new sulcatas into an enclosure with one of my artificial underground heated boxes. I have to "train" them to go in them. During winter time this is exceedingly difficult and frustrating. Every night I put them in the box and let them walk up and out in the morning whenever they want. Every evening they just park under a bush or in a corner, even though it will get down into the 30s F (0-2 C). This can go on for months. They just don't seem to "get it", even though they have a nice comfy warm area to go to. By contrast, in summer they learn to use their under ground shelters on day one. As soon as the temps start climbing past the high 80s (31+ C) they all bolt underground and stay there. In the wild, there is no such things as "too cold" for sulcatas, so they have no mechanism to deal with it, even though some of our captives get into a habit of coming and going in and out of their boxes. They can and will "park" in areas that will be too cold as night moves in. Also in the wild, there is most definitely such a thing as "too hot" (as in you will die if you stay above ground in the sun), so they have a very good brain mechanism that tells them "You are too hot. Get underground ASAP."

There are many competing factors in whatever decisions our tortoises make. Many times they will choose secure hiding places instead of proper temperatures. This is one reason why I'm not a fan of offering a wide range of temps and conditions and letting the tortoise choose. I prefer to give them what we know to be best. Many argue this, but does any one really want to make the case that it would be better to let my juvenile sulcatas "choose" to stay above ground on a below freezing night, when I know darn well it is "better" for them to be in their heated boxes? People say they have survived for millions of years without human help and we are conceited (or worse) for thinking we know better. Well that is fine if you happen to live in that animals native environment and have a few square miles of suitable habitat for them to do what they need to do to survive, but I don't. I have a few thousand square feet on an entirely different continent than where they evolved, so relying on the tortoise to "choose wisely" often results in a sick or dead animal. Also, let us not forget that living wild is harsh at times and many animals perish out there. Have we not all seen tortoise skeletons out in the wild in areas untouched by humans? I'm not talking about predation. I'm talking about drought or other "natural" occurrences. The weather and harsh conditions often kill some of them. That is not the environment I wish to provide for mine.

I hope this answers your question. I find the subject very thought provoking and worthy of discussion.

 

[Yourlocalpoet]

Every evening they just park under a bush or in a corner, even though it will get down into the 30s F (0-2 C). This can go on for months. They just don't seem to "get it", even though they have a nice comfy warm area to go to. By contrast, in summer they learn to use their under ground shelters on day one. As soon as the temps start climbing past the high 80s (31+ C) they all bolt underground and stay there.

So, they possess the faculty of realizing when to seek cooler temps when essential but not the other way around, given the choice? And this instinct or instrumentality is only absent because in their native environment they wouldn't be faced with it?

That makes perfect sense to me, and with some thought I could have answered my own question, (apologies for you having to write that lengthy reply)!

I think I must overestimate the tortoises' capacity for 'taking care of themselves' as I always assumed, in Esmeralda's case, if it's too warm, she'll seek shade, if it's too cold, she'll seek out heat, etc. Especially since she's a leopard, finding the darkest, smallest, coldest corner to hide in is pretty normal behaviour but as you said about your own, I'm pretty sure if I wasn't here to bring her inside into the warmth she'd probably just stay there all night, freezing her *** off.

I obviously don't have her trained very well (and she's been with me for 10 years) it's a good job there's no tortoise equivalent of Crufts.

She still doesn't come when I shout her either.

 

[Tom]

Its certainly a gray area. Sometimes they DO seem to seek out heat when they are too cold. But are they just going back to where they are comfortable, or are they actually thinking about their body temp being too cold and needing to be warmer.

To relate another experience: Sometimes I will make a new large outdoor enclosure in a new area and I will put the box in the "perfect" spot. Well perfect for my needs anyway. When I put the tortoise in this new enclosure they frequently park themselves in whatever area suits them at dusk. For several weeks I will put them in their house every night in an attempt to "train" (I use that term very loosely here...). SOmetimes is works and sometimes it doesn't. On occasion I will just wait and see where THEY decide to park for the first couple of nights, and then move the box to that spot. Whenever I do it this way, they immediately begin going into their box on their own every night.

Its observations like these that cause me to believe that they just go where they are most comfortable. If it happens to be a warm place, it makes our lives easier. Why is one place more comfortable than another for them? Is warmth a factor? It doesn't seem to be in some cases at least.