What is the physiology behind pyramiding?

lpcullum

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This is just because I'm curious, and like to learn about this stuff, so don't hold back! What causes the shell to form the way it does normally? And why does the keratin stack the way it does when there is a nutritional issue?
 

Tom

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Intra and extra cellular hydraulic pressure is the theory that I have seen.

The keratin and underlying bone does not malform due to nutritional issues. It malforms due to excessive dryness from the inside and out. This is the primary cause of pyramiding. Other issues can accelerate it or complicate it, but this is the main issue.
 

Yvonne G

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There was a very good thread about this just a short while ago. Maybe Jaizei can find it for us. He's real good at that.

We do have this thread in the "important threads" section of the Health section:

http://www.tortoiseforum.org/thread-41201.html

But the one I'm thinking of was just a post in someone else's thread and it gave a very good explanation and easy to understand.
 

Testudoresearch

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Tom,

I have read your reports of your experiences with G. pardalis and G. sulcata in various threads posted here. I note you recommend rearing in a high humidity environment. Your results are interesting, and I applaud your tenacity in pursuing this research. Your results are meaningful and useful. However.... I do believe that you may be misinterpreting certain causes and effects. I also note that you state, above, that you believe in some form not only of external, but some form of "internal" or"cellular" dehydration as one of the causes. This would be quite remarkable, because physiologically, it would be unique in the animal kingdom. No such process is known to science. Living cells, within an organism, are invariably in a state of homeostasis - and if dehydrated to the point of "collapse", as proponents of the theory you appear to subscribe to suggest, then they would be no longer living cells, but dead cells. There is no cytological evidence, anywhere, that this is occurring.

The areas just below the outer keratin are very well supplied by numerous blood vessels. The underlying bone too, is also well supplied and is invariably at homeostasis. If any localised "drying" did take place at that level, it would cause cell death and localised necrosis. Examination of numerous 'pyramided' carapaces fails to reveal any such condition.

So, I think we have to look beyond that theory (which remains a theory, as absolutely no-one has produced a sliver of real, hard evidence to support it). This is particularly important when a theory contradicts the established physiological and biological sciences.

I have two questions.

The first concerns Leopard tortoises in the wild which exhibit a type of raised scute phenomenon. I note you have said that you believe these are most probably ex-captives that have been released into the wild? (I hope I am not misquoting you here). While I have no count that this does occur (I have studied G. pardalis in South Africa), I believe it highly improbable it accounts for all of them - by a long way. Furthermore, there are numerous specimens in natural history museums, some dating back almost 200 years, that display identical scute formations. These were collected, in many cases from extremely remote areas, long before anyone, anywhere was keeping these animals in captivity. This is significant evidence. In the same context, it is useful to look at another species from the same part of the world, Psammobates tentorius (the Tent tortoise). These display, as a matter of course, very similar scute formations to some of these wild Leopards tortoises. Clearly, they are not all ex-captives, and again, we have collection material going back a very long way. It is quite clearly normal for them - not a result of any pathology or incorrect environment. How do they fit into the scheme of things, and if it is normal for them, why is not possible that it might also be normal for some populations of G. pardalis?

My second question is more of a practical nature. You are using a very high humidity environment to rear G. pardalis. I understand you have seen these natural habitats... if so, you must surely recognise that the environment you are using is totally different from that in the wild. It is, in general, a semi-arid, scrubby habitat. Finding pockets of high humidity in that habitat is very, very difficult. I have recorded the actual conditions right next to both juvenile and adult wild Leopard tortoises, and typically, RH ranges from 35-60% for most of the year. Very high levels are only seen at certain times of year, during and immediately following rain. For most of the time, RH is in the 40-50% range.

So as far as this goes, I have to question why people feel that such an entirely different set of microclimate conditions from that in the wild are needed in captivity? Surely, it should not be necessary. An intensely artificial method is being used here that bears almost no relation to conditions this species experiences in nature, in its natural habitat. It is important to enquire why, and what else is going wrong that demands such an approach?

Thank you for your time. I do believe these are important questions that all serious keepers and investigators have an interest in seeing addressed.
 

Yvonne G

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Hi T.R. and Welcome to the Forum!

I can speak to the second question - you say you've tested the humidity around juvenile and adult tortoises. We only recommend the high humidity approach for the first year of life. Baby leopard/sulcata tortoises hatch out during the monsoon season when there is plenty of grassy ground cover and the ground is fairly wet. So, the humidity/pyramid issue starts at birth and is usually set by the time they reach about a year of age.
 

Testudoresearch

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Yvonne G said:
Hi T.R. and Welcome to the Forum!

I can speak to the second question - you say you've tested the humidity around juvenile and adult tortoises. We only recommend the high humidity approach for the first year of life. Baby leopard/sulcata tortoises hatch out during the monsoon season when there is plenty of grassy ground cover and the ground is fairly wet. So, the humidity/pyramid issue starts at birth and is usually set by the time they reach about a year of age.

They actually tend to hatch during the very first rain or two of the season, as the ground saturates somewhat causing O2 levels in the nest and in the egg to fall dramatically, prompting emergence. This species does have a very large range, of course, and so climate generalizations are dangerous, but.... your description of climatic conditions does not concur with my observations. I studied them in Namibia (among other places), for example, where there are two periods in the year when rainfall is likely (it is quite a drought ridden area, so these are by no means a certainly), but typically there will be some rain from September-November, then again from February-April (approximately). Between these periods the ground is pretty dry, and humidity very low. There is most categorically no period of 'constant' high humidity. There are approximately 300 days of sunshine a year. Rain usually lasts for a few days at most, then dries off very quickly. It is formally classed as a semi-arid environment with a maximum annual rainfall of 600mm. This occurs in very intense downpours typically, interspersed with long-lasting, very dry periods. To put this into context, the precipitation in that locality is only twice that of AZ in the US, and is very similar to that seen in much of Testudo habitat in Southern Europe. It is not a vastly dissimilar pattern in many other habitats occupied by G. pardalis throughout its range. Periods of 'high humidity' are therefore very limited in duration. Certainly none of the areas either in Namibia or elsewhere in South Africa where I personally have studied this species have anything I would describe as a sustained period of very high humidity. They are found predominantly in dry, grassy/scrubby habitats that for most of the year are really very arid indeed, with the exception of periodic rainfall as above.

It is always difficult to really understand a habitat from mere figures. Tortoises are superb at utilizing microclimates, and have a highly developed set of behavioral tools which they use to maximum advantage. I highly recommend not drawing too many conclusions from generalized weather and climate data, but to try to visit such habitats in person, as only then do you really begin to get an accurate picture of what is going on.
 

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Testudoresearch said:
I highly recommend not drawing too many conclusions from generalized weather and climate data, but to try to visit such habitats in person, as only then do you really begin to get an accurate picture of what is going on.

I was repeating information that I gleaned from a person who actually lives in Africa and operates a sulcata reserve...Tomas Diagne.
 

julietteq

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Testudoresearch said:
Tom,

I have read your reports of your experiences with G. pardalis and G. sulcata in various threads posted here. I note you recommend rearing in a high humidity environment. Your results are interesting, and I applaud your tenacity in pursuing this research. Your results are meaningful and useful. However.... I do believe that you may be misinterpreting certain causes and effects. I also note that you state, above, that you believe in some form not only of external, but some form of "internal" or"cellular" dehydration as one of the causes. This would be quite remarkable, because physiologically, it would be unique in the animal kingdom. No such process is known to science. Living cells, within an organism, are invariably in a state of homeostasis - and if dehydrated to the point of "collapse", as proponents of the theory you appear to subscribe to suggest, then they would be no longer living cells, but dead cells. There is no cytological evidence, anywhere, that this is occurring.

The areas just below the outer keratin are very well supplied by numerous blood vessels. The underlying bone too, is also well supplied and is invariably at homeostasis. If any localised "drying" did take place at that level, it would cause cell death and localised necrosis. Examination of numerous 'pyramided' carapaces fails to reveal any such condition.

So, I think we have to look beyond that theory (which remains a theory, as absolutely no-one has produced a sliver of real, hard evidence to support it). This is particularly important when a theory contradicts the established physiological and biological sciences.

I have two questions.

The first concerns Leopard tortoises in the wild which exhibit a type of raised scute phenomenon. I note you have said that you believe these are most probably ex-captives that have been released into the wild? (I hope I am not misquoting you here). While I have no count that this does occur (I have studied G. pardalis in South Africa), I believe it highly improbable it accounts for all of them - by a long way. Furthermore, there are numerous specimens in natural history museums, some dating back almost 200 years, that display identical scute formations. These were collected, in many cases from extremely remote areas, long before anyone, anywhere was keeping these animals in captivity. This is significant evidence. In the same context, it is useful to look at another species from the same part of the world, Psammobates tentorius (the Tent tortoise). These display, as a matter of course, very similar scute formations to some of these wild Leopards tortoises. Clearly, they are not all ex-captives, and again, we have collection material going back a very long way. It is quite clearly normal for them - not a result of any pathology or incorrect environment. How do they fit into the scheme of things, and if it is normal for them, why is not possible that it might also be normal for some populations of G. pardalis?

My second question is more of a practical nature. You are using a very high humidity environment to rear G. pardalis. I understand you have seen these natural habitats... if so, you must surely recognise that the environment you are using is totally different from that in the wild. It is, in general, a semi-arid, scrubby habitat. Finding pockets of high humidity in that habitat is very, very difficult. I have recorded the actual conditions right next to both juvenile and adult wild Leopard tortoises, and typically, RH ranges from 35-60% for most of the year. Very high levels are only seen at certain times of year, during and immediately following rain. For most of the time, RH is in the 40-50% range.

So as far as this goes, I have to question why people feel that such an entirely different set of microclimate conditions from that in the wild are needed in captivity? Surely, it should not be necessary. An intensely artificial method is being used here that bears almost no relation to conditions this species experiences in nature, in its natural habitat. It is important to enquire why, and what else is going wrong that demands such an approach?

Thank you for your time. I do believe these are important questions that all serious keepers and investigators have an interest in seeing addressed.

Very interesting! I have tried to create a table that allows for a very humid climate, to a dry one and everything in between. The torts themselves can decide where they want to be. I am keeping track of how much time each tortoise spends in each habitat. For a setup of my enclosure you can check http://www.tortoiseforum.org/thread-84008.html
 

Neal

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Testudoresearch - I was excited to read your posts as the questions you have asked are ones that I keep challenging myself with having raised smooth tortoises in non-high humid environments. And reading that you have apparently done some detailed research on wild leopard tortoises, I find absolutely fascinating.

Let me ask you a general question. What do you believe causes and/or influences pyramiding in tortoises? If you have a theory (or theories), have you any pictures or data as support that you could share with us?
 

Testudoresearch

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Yvonne G said:
Testudoresearch said:
I highly recommend not drawing too many conclusions from generalized weather and climate data, but to try to visit such habitats in person, as only then do you really begin to get an accurate picture of what is going on.

I was repeating information that I gleaned from a person who actually lives in Africa and operates a sulcata reserve...Tomas Diagne.

That is a very different locality (Senegal) indeed than G. pardalis inhabit. Totally different - a huge distance away. When referencing tortoise habitats, even a few miles can have a massive impact, due to coastal influences and particularly altitude effects. I could take you to some localities with very high density Testudo populations, but if you look only 7 miles away, there are none at all. The maximum-minimum temperatures are different, precipitation is different, and average humidity levels are different. So different that one area offers an evidently very good set of climatic conditions, but the other area does not. Exactly the same situation applies in other habitats. G. sulcata also has a different behavior pattern, utilizing very deep burrows, whereas G. pardalis uses shallow scrapes... the microclimates they experience are utterly dissimilar. It is also important to take into account that within Senegal you find both G. sulcata and Kinixys belliana - reflecting the range of climatic variability and microclimates available.
 

Saleama

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Interestingly enough, with the tent tortoise, the ones from the drier areas happen to be the smoothest? Still, I have been using the humid method with Leopards and Sulcatas in the exact same conditions and I am seeing pretty smooth leopards and not a whole lot of pyramiding in the Sulcatas started humid and noticable decreases in the ones started dry. Of course, I can only speak for my very limited number of animals and the short time I have had them, five months.
 

Testudoresearch

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Saleama said:
Interestingly enough, with the tent tortoise, the ones from the drier areas happen to be the smoothest? Still, I have been using the humid method with Leopards and Sulcatas in the exact same conditions and I am seeing pretty smooth leopards and not a whole lot of pyramiding in the Sulcatas started humid and noticable decreases in the ones started dry. Of course, I can only speak for my very limited number of animals and the short time I have had them, five months.

I am not really trying to dispute the fact that the development of scutes can be affected by varying levels of humidity - especially at both extremes, very dry and very wet. The empirical evidence is pretty convincing that it can be, and furthermore, there are straightforward physical reasons as to how and why this is possible. None of these answers requires breaking any established laws of either physiology or materials science.

What does concern me is where recourse is made to claims which are not accurate, and where conclusions are drawn that have absolutely no evidence to support them. Indeed, in some instances, all available evidence flatly contradicts the claims being made. Also, some of these conclusions can be very damaging to the long-term health of the animals involved. It also concerns me greatly that broad claims are often made which are incredibly easy to disprove conclusively, yet those claims gain wide acceptance among many keepers. One such example of this is that a high humidity rearing environment is "necessary" to produce excellent, smooth growth in tortoises. This is categorically untrue. I am quite happy to post photos of a number of species I have personally captive-bred over the years, not one of which was subjected to these artificial high humidity conditions and which I feel are good examples of what can be achieved without employing such methods.

The article by Wolfgang is interesting, because he does at least illustrate the critical difference between a pathological 'pyramiding' typical of animals raised on poor diets and in poor conditions in captivity and a class of 'pyramiding' that may be seen in apparently 100% healthy wild tortoises living in their natural habitat (G. pardalis being one example where this occurs). The bone sections are particularly revealing, and fully match my own findings in that regard.

I have some very interesting (similar) sections of G. pardalis and G. sulcata skeletal material, also many hundreds of examples of various Testudo.
 

wellington

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I would love to see pictures of your smooth tortoises. Also, with description of where you live and how you did raise them. Raising a leopard smooth in Florida is much easier then raising one in Arizona. Although,we have seen torts raised in Florida that does not benefit from some of the methods mention on this forum and they have pyramiding, where others, that do benefit from the suggestions of this forum don't. The high humidity way works for the different areas that we all live. If we all lived in Africa we probably wouldn't have to give such a high humidity if we left our torts to live outside and let them roam the whole range of area they naturally have. Duplicating the wide range available to them in the wild is impossible to duplicate in captivity. Keeping them as pets, prevents most or all if us from wanting to just let them loose in an area to fend for themselves.
It also depends on what some consider smooth. A couple other members, have experimented with different ways of raising smooth leopards and have admitted that theirs are not as smooth as Toms and his closed chambers high humidity. My leopard, unfortunately was raised with the natural humidity of my house for about 6 months of his life and has pyramiding.
Proper diet and hydration is an important factor, but the results of the high humidity speaks for itself. I sure would hate for people to go back to low or no humidity, just to have a bunch of unnatural pyramiding tortoises being the end result.
 

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I'm not very science-y and I'm fairly new to tortoises...but what if humidity, daily soaks, and hydration ARE helping prevent pyramiding, but not at a cellular level as you asked about before? Could it be aiding in digestion and therefore the absorption of nutrients, or other processes like that? Being very well hydrated has been proven to be beneficial in many species (duh)...for instance, I probably don't drink as much water as I should and eat and drink a lot of dehydrating foods, but I feel noticeably better when well hydrated. It's not necessarily that I am DEhydrated normally, but function better when I am focused on staying hydrated. By forcing our tortoises to stay in environments that aren't drying to the skin/keratin/whatever (obviously, you'd stay better hydrated in a rainforest than a desert), "force hydrating" them in daily soaks, and having water available at all times, we're keeping their body at a higher functioning level, aren't we? It makes sense then, that most, if not all, of their bodily processes would be functioning better by staying hydrated and these processes combined could be helping to prevent pyramiding.

Maybe these aren't "natural conditions," but when kept in a back yard or small indoor pen, tortoises can't take advantage of the various microclimates they would have access to in the wild.
 

nearpass

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It was presented to me several years ago by a European tortoise keeper, the source I do not remember, that 'over feeding' and too rapid growth contribute to excessive pyramiding in captive tortoises. By over feeding, I mean that in captivity our animals have to work very little for foods that may well be much more nutrient dense than what they would ever scrounge for much of the time in the wild. I suspect many captive raise animals have accelerated growth compared to wild roaming ones, and much less exercise is involved in their finding food. This is certainly not the complete picture, and I am no biologist, but might it not play a part?
 

Team Gomberg

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The OP isn't doubting that high humidity in a closed chamber produces a smooth shell. He is doubting that raising them in high humidity for the first year mimic's their natural environment.
Is this correct?
Let's make sure we discuss the correct point.

When you take temperature and humidity readings, what level do you sample? Measuring from 6' above the ground will have different readings than measuring under a bush or at the base of thick grass. The moisture at the leopard hatchling level is much higher.

@ nearpass, do we "know" that wild ones grow slower than captive ones? I'm not asking sarcastically. I want to know if any studies can prove this. It seems like we assume this.
The smaller you are in the wild, the longer you are lower on the food chain. This makes me think they aren't as slow growing as some claim. Especially when we see how fast they grow in good conditions. There are also those who have been free fed that are smooth and ones with restricted food intake that are pyramided.

I'd love to see any information that documents wild hatchling growth, one way or the other.
 

wellington

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Heather, maybe some clarity is needed. I took it that the high humidity (80%)is not what they would naturally get in the wild, that it is more like 40-60% and that they would not get it as long or constant as it would be in the closed chambers.
 

Team Gomberg

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Hydration is what matters. The constant high humidity is one way of achieving that.

This is obvious but I'll say it anyway. In the wild they have access to micro climates. They don't walk around in 80% humidity 24/7 like they do inside my chamber or inside Tom's. However, their environment is humid and they do spend time at the base of plants with even higher humidity than what is recorded at "people level".

Once Levi hit 4" in length he spent all day outside here in SoCal. His pen was heavily planted with tall grasses and lots of overgrown plants. I'm a stay at home mom so I went out multiple times a day and watered it down. He then slept inside the humid chamber. He was perfectly smooth with this routine. I knew inside the chamber was 80% RH minimally but outside in his grasses? I don't actually know because I never recorded the numbers. (This just inspired me to start recording that)
So, even if Africa isn't 80% RH all the time at our level, I bet its still pretty high at the base of plants where they are and that they spend enough time in those conditions to be hydrated enough for smooth growth.

Remember, we are raising babies in the high humidity. Not juveniles or adults. The reason we don't know much about what babies do in the wild is because no one sees enough of them. But we know they are there because the species hasn't gone extinct. If the babies aren't seen it is probably because they are hiding under all the brush. That humidity level is what matters. That is why they stay hydrated and grow smooth. That is why we create a close chamber to efficiently and cost effectively create that micro climate.
 

Testudoresearch

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nearpass said:
It was presented to me several years ago by a European tortoise keeper, the source I do not remember, that 'over feeding' and too rapid growth contribute to excessive pyramiding in captive tortoises. By over feeding, I mean that in captivity our animals have to work very little for foods that may well be much more nutrient dense than what they would ever scrounge for much of the time in the wild. I suspect many captive raise animals have accelerated growth compared to wild roaming ones, and much less exercise is involved in their finding food. This is certainly not the complete picture, and I am no biologist, but might it not play a part?

Absolutely it plays a major role. This is not a theory - it is an established fact, and has been known for years. It is not only true in chelonia, but in other animals too. It is discussed in most veterinary nutritional texts. In the vast majority of cases, captive bred and raised animals can be anything from 100% to 400% larger than an equivalent aged wild specimen of the same species after 3 or four years growth. Wild growth, in most situations, is really quite slow. This is especially true of semi-arid habitat tortoises which experience strong seasonal variations in food availability (typically two fairly short periods of abundance, one in Spring (March-May) and again in Fall (September-October). Activity, and feeding, are (in the Mediterranean, for example) very low to non-existent over the heat of summer, and again very low to non-existent from December-February (there are a few exceptions to this, but that is very average and typical). There are only a few months of the year when what you might call 'serious' feeding and high activity occur, and even then, it takes place on a daily cycle, of short period in the mornings, very little at mid-day, and often again in late afternoon. They are most certainly not feeding constantly, or every day. There can be periods of days, or even weeks, or months between feeds. In many areas they both brumate (hibernate) and estivate. The precise pattern varies according to locality and altitude, but it is very different from a typical captive situation where daily feeding and (often) a 365-day-a year activity cycle is the norm. Also... the digestibility of wild foods tend to be considerably lower than most captive diets. A combination of a highly digestible diet plus extended feeding cycles predictably result in excess growth compared to a wild example.

As mentioned, veterinary nutritional texts recognize this link. Donoghue and and Langenberg (1996) state that "the demands of shell growth may predispose juvenile chelonians to MBD”. MacArthur (2004) observes that “metabolic bone disease is most frequently encountered in the rapidly growing juvenile”. Ware (1998) points out that “because the majority of nutritional problems become apparent during growth, bone disease often occurs where young animals are being reared”. Rapid growth is therefore clearly established as an important co-factor in the development of shell deformities in chelonia, as it is an established and very common co-factor in MBD in mammals, birds and other reptiles, such as iguanas and bearded dragons (Rubel, Isenbugel and Wolvekamp, 1990). I am not aware of a single reputable text that disputes or challenges this in any way. It is also recognized in agricultural nutrition (hence high energy diets deliberately designed to produce high growth rates).

In simple terms... rapid growth makes achieving good bone density very difficult. As has been pointed out regularly for over over 20 years in terms of tortoise keeping "Any deficiency-induced skeletal disorders will obviously manifest much more rapidly and with greater severity in an animal undergoing a rapid growth phase than in a fully grown adult". If you grow animals at a high rate, it makes nutrition very, very critical indeed in terms of calcium and D3 supply in particular. Any deficiency at all will result in irreversible poor bone density and general MBD issues arising. The evidence for this is overwhelming and is easy to verify. The captive carapace section illustrated in Wolfgang's text is typical. I will post some further examples shortly for you to compare.


wellington said:
Heather, maybe some clarity is needed. I took it that the high humidity (80%)is not what they would naturally get in the wild, that it is more like 40-60% and that they would not get it as long or constant as it would be in the closed chambers.

Correct.
 
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