Does Diet Effect Shell Pyrmiding

[Len B]

I would like to have a discussion about pyramiding of young tortoises shells. Do you think their diet can cause pyramiding? I have thoughts mainly for sulcatas and hermanns tortoises. Because they are the ones I have worked with and raised from hatchlings. People here on the Forum always say diet doesn't cause pyramiding and I say it can, if not offered in the proper way and not fed items to counteract it.

 

[Alex and the Redfoot]

From what I read in papers and other sources besides TFO, pyramiding is a multi-factor equation:
1. The primary cause is "too dry conditions": keratin dries out, puts pressure on underlying bones (rather soft in early years) and deforms them.
2. "Too dry" itself depends on complimentary factors:
* with artificial heat sources like basking lamps keratin dries out fast and we mitigate it with rising humidity
* "power feeding" and low calcium diet result in faster growth of softer bone tissue and wider keratin "rings" which put extensive pressure when harden - we mitigate it with higher humidity too.
* genetics - some species are more prone to pyramiding and among one species there is some variation too

We can encounter pyramiding in wild tortoises too (who, presumably, have right diet and only natural sunlight). Some keepers/researchers attribute this to years of draught and deforestation of habitats.

Len, can you share some thoughts on proper diet? (As I understand, you feed a lot of items with high moisture content and sprayed with water to promote internal hydration)

 

[dada625]

From what I read in papers and other sources besides TFO, pyramiding is a multi-factor equation:
1. The primary cause is "too dry conditions": keratin dries out, puts pressure on underlying bones (rather soft in early years) and deforms them.
2. "Too dry" itself depends on complimentary factors:
* with artificial heat sources like basking lamps keratin dries out fast and we mitigate it with rising humidity
* "power feeding" and low calcium diet result in faster growth of softer bone tissue and wider keratin "rings" which put extensive pressure when harden - we mitigate it with higher humidity too.
* genetics - some species are more prone to pyramiding and among one species there is some variation too

We can encounter pyramiding in wild tortoises too (who, presumably, have right diet and only natural sunlight). Some keepers/researchers attribute this to years of draught and deforestation of habitats.

Len, can you share some thoughts on proper diet? (As I understand, you feed a lot of items with high moisture content and sprayed with water to promote internal hydration)

I totally agree with you.
I have recently been studying the factors that affect the width of the keratin "rings". The tortoise's carapace consists of two layers, the upper layer is the keratin and the lower layer is the bone. If tortoise take in a lot of protein but not the same amount of calcium, the growth rate of the lower layer will not keep up with the upper layer, causing the keratin "rings" to become wider or the pyramiding. (The lower layer does not grow fast enough and does not provide enough surface area for the upper keratin, which put extensive pressure when keratin be harden)

 

[Alex and the Redfoot]

I totally agree with you.
I have recently been studying the factors that affect the width of the keratin "rings". The tortoise's carapace consists of two layers, the upper layer is the keratin and the lower layer is the bone. If tortoise take in a lot of protein but not the same amount of calcium, the growth rate of the lower layer will not keep up with the upper layer, causing the keratin "rings" to become wider or the pyramiding. (The lower layer does not grow fast enough and does not provide enough surface area for the upper keratin, which put extensive pressure when keratin be harden)
View attachment 393377

If you are researching this topic I strongly suggest to look at Markw84 posts about pyramiding. For example:
1. https://tortoiseforum.org/threads/smooth-to-pyramiding.224107/#post-2177103
2. https://tortoiseforum.org/threads/pyramiding-–-solving-the-mystery.164261/
3. https://tortoiseforum.org/threads/the-cause-of-pyramiding.143520/

P.S. I hope it's not your tortoise on the photo

 

[dada625]

If you are researching this topic I strongly suggest to look at Markw84 posts about pyramiding. For example:
1. https://tortoiseforum.org/threads/smooth-to-pyramiding.224107/#post-2177103
2. https://tortoiseforum.org/threads/pyramiding-–-solving-the-mystery.164261/
3. https://tortoiseforum.org/threads/the-cause-of-pyramiding.143520/

P.S. I hope it's not your tortoise on the photo

Thank you! This is very helpful to me.
Nooo, it's just a photo I found on the Internet.

 

[Fluffy]

There are lots of people who raise Mediterranean tortoises in a naturalistic way. Starting them outside without a closed chamber. There are so many variables when raising tortoises this way that it's sometimes hard to quantify exactly what factors are at play. I'm sure diet plays a huge part when doing it this way. I know closed chambers work but I also know it's not the only way to raise smooth tortoises. It is probably the easiest way and allows you to have other factors that are not ideal, such as food. Very interesting discussion Len. Lets hope we get a chance to explore it further.

 

[Markw84]

I would like to have a discussion about pyramiding of young tortoises shells. Do you think their diet can cause pyramiding? I have thoughts mainly for sulcatas and hermanns tortoises. Because they are the ones I have worked with and raised from hatchlings. People here on the Forum always say diet doesn't cause pyramiding and I say it can, if not offered in the proper way and not fed items to counteract it.

In countless experiments over the past 6 decades I have not been able to find any relationship between diet and pyramiding. I've tried all kinds of diets in side by side experiments raising tortoises and diet had no effect. The same with rate of growth. Fast growth groups and slow growth groups from the same clutches had no change in the amount of pyramiding.

In studying the way the tortoise shell grows, I also find no way diet or fast growth can affect pyramiding. Bone growth drives keratin production. It is the expansion of the shell by the growth of the underlying bone that then widens the gap between scutes and stimulates new keratin to be laid down at the seams. Keratin growth is stimulated by bone growth and the separation of the scutes.

Poor diet and low calcium will affect bone and can then lead to MBD. It also can lead to poor metabolic function in general. That, however, does not lead to pyramiding.

It is the keratin that is the key to pyramiding. Keratin is the only driver of pyramiding. It is the imbalance of moisture content - upper vs lower - that causes keratin to curl and put pressure on the underlying bone. New keratin is very hygroscopic. The exposed top side of the new keratin if not able to maintain proper hydration will harden and not swell, while the bottom side will. I think most of us think of this as pressing down on the bone and making it deform. However, it is not just pressure. It is the stimulation of subsequent osteoclast genesis that actually breaks down bone under pressure and reforms (osteoblast gensis) on the underside of that bone that is now under slight tension. The bone rebuilds. Valleys begin to form. This is independent of whether the bone is dense or more porus due to improper calcium/ Vit D levels.

So to look at the causes of pyramiding, we must look at causes for the keratin moisture imbalance. Humidity. UV light exposure. Excess heat. Plus the way altered behavioral patterns will affect exposure to those things. A young captive tortoise will not behave the way a true wild tortoise would once they become accustom to the security and food and routines of your care.

AND... I believe we see wild pyramided tortoises, not because it is a natural thing that can occur. But because we have altered their environment and we are not seeing true wild tortoises. They now have reservoirs providing food growth and irrigated crops to feed on in dry times where before there was not food available that time of year and they did not grow. Many "wild specimens" are actually ones that had been kept in pens and/or fed by locals until poachers or researchers came to collect them.

 

[zovick]

In countless experiments over the past 6 decades I have not been able to find any relationship between diet and pyramiding. I've tried all kinds of diets in side by side experiments raising tortoises and diet had no effect. The same with rate of growth. Fast growth groups and slow growth groups from the same clutches had no change in the amount of pyramiding.

In studying the way the tortoise shell grows, I also find no way diet or fast growth can affect pyramiding. Bone growth drives keratin production. It is the expansion of the shell by the growth of the underlying bone that then widens the gap between scutes and stimulates new keratin to be laid down at the seams. Keratin growth is stimulated by bone growth and the separation of the scutes.

Poor diet and low calcium will affect bone and can then lead to MBD. It also can lead to poor metabolic function in general. That, however, does not lead to pyramiding.

It is the keratin that is the key to pyramiding. Keratin is the only driver of pyramiding. It is the imbalance of moisture content - upper vs lower - that causes keratin to curl and put pressure on the underlying bone. New keratin is very hygroscopic. The exposed top side of the new keratin if not able to maintain proper hydration will harden and not swell, while the bottom side will. I think most of us think of this as pressing down on the bone and making it deform. However, it is not just pressure. It is the stimulation of subsequent osteoclast genesis that actually breaks down bone under pressure and reforms (osteoblast gensis) on the underside of that bone that is now under slight tension. The bone rebuilds. Valleys begin to form. This is independent of whether the bone is dense or more porus due to improper calcium/ Vit D levels.

So to look at the causes of pyramiding, we must look at causes for the keratin moisture imbalance. Humidity. UV light exposure. Excess heat. Plus the way altered behavioral patterns will affect exposure to those things. A young captive tortoise will not behave the way a true wild tortoise would once they become accustom to the security and food and routines of your care.

AND... I believe we see wild pyramided tortoises, not because it is a natural thing that can occur. But because we have altered their environment and we are not seeing true wild tortoises. They now have reservoirs providing food growth and irrigated crops to feed on in dry times where before there was not food available that time of year and they did not grow. Many "wild specimens" are actually ones that had been kept in pens and/or fed by locals until poachers or researchers came to collect them.

Do you believe that wild Sri Lankan Stars also have pyramiding due to altered habitat or some other human factor? It seems rather unlikely to me based on what I have observed. I have seen photos of Sri Lankan Stars taken in the wild 50-60 years ago which exhibited what would be called fairly severe pyramiding while others did not have the pyramiding.

Also the Star Tortoise illustrated in Sowerby and Lear's book from 1871 is shown with fairly high pyramids. It is hard to imagine that human interference was taking place when that tortoise drawing was done.

Also the South African Psammobates ssp. have fairly pyramided shells as illustrated in that same book. I had some wild caught P. tentorius verroxii in the early 1970's which were quite pyramided.

What do you think? Are some species just naturally pyramided or is there another explanation?

 

[Tortoise Mom TRAVIS 2025]

I would like to have a discussion about pyramiding of young tortoises shells. Do you think their diet can cause pyramiding? I have thoughts mainly for sulcatas and hermanns tortoises. Because they are the ones I have worked with and raised from hatchlings. People here on the Forum always say diet doesn't cause pyramiding and I say it can, if not offered in the proper way and not fed items to counteract it.

No One ever talks about Oxalates from Spinach, Kale, maybe other etc... They do interfere w/ metabolism. No one Ever talks about their Gut Microbes either. Because Travis does not like to stay in water to soak I began using towels or wash cloths soaked in Spring Water . I do not put them in Chlorinated water except on rare occassions.

In countless experiments over the past 6 decades I have not been able to find any relationship between diet and pyramiding. I've tried all kinds of diets in side by side experiments raising tortoises and diet had no effect. The same with rate of growth. Fast growth groups and slow growth groups from the same clutches had no change in the amount of pyramiding.

In studying the way the tortoise shell grows, I also find no way diet or fast growth can affect pyramiding. Bone growth drives keratin production. It is the expansion of the shell by the growth of the underlying bone that then widens the gap between scutes and stimulates new keratin to be laid down at the seams. Keratin growth is stimulated by bone growth and the separation of the scutes.

Poor diet and low calcium will affect bone and can then lead to MBD. It also can lead to poor metabolic function in general. That, however, does not lead to pyramiding.

It is the keratin that is the key to pyramiding. Keratin is the only driver of pyramiding. It is the imbalance of moisture content - upper vs lower - that causes keratin to curl and put pressure on the underlying bone. New keratin is very hygroscopic. The exposed top side of the new keratin if not able to maintain proper hydration will harden and not swell, while the bottom side will. I think most of us think of this as pressing down on the bone and making it deform. However, it is not just pressure. It is the stimulation of subsequent osteoclast genesis that actually breaks down bone under pressure and reforms (osteoblast gensis) on the underside of that bone that is now under slight tension. The bone rebuilds. Valleys begin to form. This is independent of whether the bone is dense or more porus due to improper calcium/ Vit D levels.

So to look at the causes of pyramiding, we must look at causes for the keratin moisture imbalance. Humidity. UV light exposure. Excess heat. Plus the way altered behavioral patterns will affect exposure to those things. A young captive tortoise will not behave the way a true wild tortoise would once they become accustom to the security and food and routines of your care.

AND... I believe we see wild pyramided tortoises, not because it is a natural thing that can occur. But because we have altered their environment and we are not seeing true wild tortoises. They now have reservoirs providing food growth and irrigated crops to feed on in dry times where before there was not food available that time of year and they did not grow. Many "wild specimens" are actually ones that had been kept in pens and/or fed by locals until poachers or researchers came to collect them.

Animals really treat themselves by instinct too so there is the likelihood what they need at any given time is not there. Most are not helping their tortoises to burrow either...they may eat roots as well. We had Iguanas for 24 years. We had one that was robust but died at 22 YRs from Kidney failure. She was trained to go Potty in the shower and would climb over...into chlorinated water. She could have gotten into runoff water from fertilized lawns next door. Or Virus. Our other Iguana had metabolic issues from the start. We bought her from a per store at about a year old. At first glance we thought it was calcium deficiency but our vet figured out it was Potassium. Now in Texas we often drink a couple of teaspoons of Vinegar w/ mint/lemon in ice water for muscle cramping in the heat. Vinegar does even out acidity. So.... And against the idea that it is too much protein. I think a varied diet rich in weeds and grasses and Hay is great. Grasses and Hay are 18-22% Veggie Protein. So one has to wonder if the Burrowing in mineral rich dirt does a lot more for them than we think. Especially when they are going thru immense growth spurts...supposedly they urinate and defecate in their own burrows...probably as identification but also for moisture and ," Fast Food" in case they need it in drought....I want to mention here the Indians of America and Including Alaska use CHAGAS Mushrooms for treating Illnesses, including cancer---supposedly 100% tumor suppressive: because it is so nutritious. It might be a great source of Trace minerals. It grows wild all over...especially on birch, cottonwood and aspens...

 

[Alex and the Redfoot]

In countless experiments over the past 6 decades I have not been able to find any relationship between diet and pyramiding. I've tried all kinds of diets in side by side experiments raising tortoises and diet had no effect. The same with rate of growth. Fast growth groups and slow growth groups from the same clutches had no change in the amount of pyramiding.

In studying the way the tortoise shell grows, I also find no way diet or fast growth can affect pyramiding. Bone growth drives keratin production. It is the expansion of the shell by the growth of the underlying bone that then widens the gap between scutes and stimulates new keratin to be laid down at the seams. Keratin growth is stimulated by bone growth and the separation of the scutes.

Poor diet and low calcium will affect bone and can then lead to MBD. It also can lead to poor metabolic function in general. That, however, does not lead to pyramiding.

It is the keratin that is the key to pyramiding. Keratin is the only driver of pyramiding. It is the imbalance of moisture content - upper vs lower - that causes keratin to curl and put pressure on the underlying bone. New keratin is very hygroscopic. The exposed top side of the new keratin if not able to maintain proper hydration will harden and not swell, while the bottom side will. I think most of us think of this as pressing down on the bone and making it deform. However, it is not just pressure. It is the stimulation of subsequent osteoclast genesis that actually breaks down bone under pressure and reforms (osteoblast gensis) on the underside of that bone that is now under slight tension. The bone rebuilds. Valleys begin to form. This is independent of whether the bone is dense or more porus due to improper calcium/ Vit D levels.

So to look at the causes of pyramiding, we must look at causes for the keratin moisture imbalance. Humidity. UV light exposure. Excess heat. Plus the way altered behavioral patterns will affect exposure to those things. A young captive tortoise will not behave the way a true wild tortoise would once they become accustom to the security and food and routines of your care.

AND... I believe we see wild pyramided tortoises, not because it is a natural thing that can occur. But because we have altered their environment and we are not seeing true wild tortoises. They now have reservoirs providing food growth and irrigated crops to feed on in dry times where before there was not food available that time of year and they did not grow. Many "wild specimens" are actually ones that had been kept in pens and/or fed by locals until poachers or researchers came to collect them.

Mark, can you tell more about experiment settings (main and control groups)?

My common sense tells me that wider keratin layers should "curve" more (have higher tension) and as such trigger more intensive bone remodelling. Some EU keepers seem to work under the same assumption and limit food intake to control width of growth rings. Presumably, this gives more time for bone matrix to harden. Photos of their collections show nice results of that approach (I should note that hydration and heat sources exposure are also managed, so it's not the diet alone).

Another thing is that we have a lot of "backyard tortoises" here in Cyprus and many young Testudo tortoises hatch/brumate outdoors and grow pretty smooth. In summer, daytime humidity is usually in 50-60% so, probably, we naturally provide the optimum conditions.

 

[Tom]

Mark, can you tell more about experiment settings (main and control groups)?

My common sense tells me that wider keratin layers should "curve" more (have higher tension) and as such trigger more intensive bone remodelling. Some EU keepers seem to work under the same assumption and limit food intake to control width of growth rings. Presumably, this gives more time for bone matrix to harden. Photos of their collections show nice results of that approach (I should note that hydration and heat sources exposure are also managed, so it's not the diet alone).

Another thing is that we have a lot of "backyard tortoises" here in Cyprus and many young Testudo tortoises hatch/brumate outdoors and grow pretty smooth. In summer, daytime humidity is usually in 50-60% so, probably, we naturally provide the optimum conditions.

Something to keep in mind in discussions like this is microclimate. The humidity stats you quote are collected from the international standard of 2 meters above the ground and out in the open. Obviously, this is not whee the tortoises are spending their time. Humidity is much higher down in the brush, or dug into pallets or root balls of bushes.

 

[Tom]

In agreement with Mark's eloquent and technical explanation, I'll word it in my much more simplistic terms: In practice, you can feed just about any reasonable diet and if conditions are dry, the tortoise will pyramid. If fed a spartan diet in dry conditions, the tortoise will grow slowly, but still pyramid. If fed a rich, high protein diet in dry conditions, the tortoise will grow faster and demonstrate the same pyramiding.

The converse is also true: You can feed any diet you want to a tortoise in humid conditions and they will not pyramid. I've seen sulcatas eating cat kibble and living in a burrow in Florida that were smooth as a bowling ball and very large for their age. I've seen sulcatas nearly starved to death here in CA, fed a diet of dry hay or grass and little else ever, completely undersized for their age, that were severely pyramiding due to the dry conditions.

It is because of these experiences with my own tortoises, and observation of thousands of other tortoises all over the whole world, that I don't think the food has anything to do with pyramiding, other than affecting the rate of growth.

 

[The_Four_Toed_Edward]

Something to keep in mind in discussions like this is microclimate. The humidity stats you quote are collected from the international standard of 2 meters above the ground and out in the open. Obviously, this is not whee the tortoises are spending their time. Humidity is much higher down in the brush, or dug into pallets or root balls of bushes.

And with some species, these micro climates include burrows, humid and cool burrows.

 

[Markw84]

Do you believe that wild Sri Lankan Stars also have pyramiding due to altered habitat or some other human factor? It seems rather unlikely to me based on what I have observed. I have seen photos of Sri Lankan Stars taken in the wild 50-60 years ago which exhibited what would be called fairly severe pyramiding while others did not have the pyramiding.

Also the Star Tortoise illustrated in Sowerby and Lear's book from 1871 is shown with fairly high pyramids. It is hard to imagine that human interference was taking place when that tortoise drawing was done.

Also the South African Psammobates ssp. have fairly pyramided shells as illustrated in that same book. I had some wild caught P. tentorius verroxii in the early 1970's which were quite pyramided.

What do you think? Are some species just naturally pyramided or is there another explanation?

Bill, have thought a lot about this over my research time. I believe the "design" of the tortoise shell is the issue. It will only work to have unprotected keratin growing when you can keep the upper side hydrated. That was perhaps not the issue when tortoises first started evolving and the earth (and their range) was much different. The design was "made" for tropical conditions. As earth's climate changed and the range of tortoises extended into less desirable areas, this design becomes a challenge. Mammals/predators out-competed tortoises for foods and the tortoises ended up in the fringe environments in may cases. In the drier periods of climate, like we are in now, tortoises have to adapt to borrow or stay hidden in plant cover more and more to grow "naturally". In some areas, and in some periods this can become impossible.

We tend to look at things in our human perspective in a very short-term way. For example, look at all the people who look at the climate of the 'natural range" of a tortoise to try to figure out what a tortoise really needs. Well... that tortoise evolved and lived for 100s of thousands, if not millions of years in a very different climate than what you see now. It is now "toughing it out" in the hard times! Look at the sulcata. Just 6000 years ago the Sahel of Africa was a tropical forest. Sulcatas lived with that for more time than the conditions you see now. So what are the true conditions that allow a sulcata to thrive?

I see tortoises as partly relics from the past. Evolved to live in climates that for many, do not exist currently. They are so resilient, they can survive these tough times, and as the climate cycles back, they can find times again to thrive.

 

[The_Four_Toed_Edward]

We tend to look at things in our human perspective in a very short-term way. For example, look at all the people who look at the climate of the 'natural range" of a tortoise to try to figure out what a tortoise really needs. Well... that tortoise evolved and lived for 100s of thousands, if not millions of years in a very different climate than what you see now. It is now "toughing it out" in the hard times! Look at the sulcata. Just 6000 years ago the Sahel of Africa was a tropical forest. Sulcatas lived with that for more time than the conditions you see now. So what are the true conditions that allow a sulcata to thrive?

I think this is an important point. If you look at studies about Russian tortoise behavior in the wild, you will notice their climate seems to be far from ideal as their activity is very limited. Most of their time is spent in burrows, brumating or aestivating.

 

[The_Four_Toed_Edward]

I think this is an important point. If you look at studies about Russian tortoise behavior in the wild, you will notice their climate seems to be far from ideal as their activity is very limited. Most of their time is spent in burrows, brumating or aestivating.

For example:
"The annual activity period of steppe tortoises can be quite short, depending on the geographic location. ATAEV (1985) reports an annual activity period in Turkmenistan of about 100 days. In general, the tortoises emerge from hibernation in February/March and use the short time until the dry period begins for intensive foraging, mating, and for oviposition. After hibernation, the tortoises sometimes deliberately ingest soil that is rich in minerals, as do the American desert tortoises (MARLOW & TOLLESTRUP 1982). Then they feed on almost all available plants, which are young and juicy at first, but become drier and more straw-like later. In most of the distribution area, the onset of aestivation is already in May. Often aestivation directly proceeds into hibernation, and only rarely specimens are seen in autumn. We do not have any data about the temperature in the burrows during the summer months. Temperatures of 5 to 10 °C have been measured in winter, air and body temperatures were the same."

Fritz, Christoph, and Beate Pfau. 2002. “Care and Breeding of the Afghan or Steppe Tortoise, Testudo horsfieldii.” ResearchGate

https://www.researchgate.net/profile/Beate-Pfau/publication/279193394_Care_and_Breeding_of_the_Afghan_or_Steppe_tortoise_Testudo_horsfieldii/links/558db0d208ae1e1f9bab241a/Care-and-Breeding-of-the-Afghan-or-Steppe-tortoise-Testudo-horsfieldii.pdf

I remeber reading on another article, that during the active period tortoises were observed to be active for as little as 15 minutes per day. As for recreating natural conditions, I don't know anyone recreating aestivation or overall striving for that little activity. With the care promoted here on the forum, russians are way more active.

It would be interesting to see what the humidity and temperatures in the burrows are like year round though.

 

[Markw84]

Mark, can you tell more about experiment settings (main and control groups)?

My common sense tells me that wider keratin layers should "curve" more (have higher tension) and as such trigger more intensive bone remodelling. Some EU keepers seem to work under the same assumption and limit food intake to control width of growth rings. Presumably, this gives more time for bone matrix to harden. Photos of their collections show nice results of that approach (I should note that hydration and heat sources exposure are also managed, so it's not the diet alone).

Another thing is that we have a lot of "backyard tortoises" here in Cyprus and many young Testudo tortoises hatch/brumate outdoors and grow pretty smooth. In summer, daytime humidity is usually in 50-60% so, probably, we naturally provide the optimum conditions.

The keratin does not curve in the sense of changing direction of existing keratin. Perhaps explained this way; When the bone grows and pulls the scutes apart, new keratin is formed in a very thin layer to fill in that gap. It will then thicken to match the existing scute thickness. However, if the keratin on top dries out - no new keratin growth happens there, The keratin beneath remains hydrated and new keratin continues to form on the bottom only. Since the top is now "set" the only growth is expanding down. This puts the thin, epithelial layer that is between the keratin and bone under compression. That triggers the bone remodeling (osteoclast genesis) and the valley starts to form.

Actually a wide growth seam creates a smaller angle of pyramiding than a narrow seam. The most dramatically pyramided tortoises grew rather slowly in very dry conditions. The keratin layer is quite thin in tortoise shells. So think of it as a wide seam of 2mm ends up growing down the 1/2mm thickness. A 1/2mm growth seam also grows down the 1/2mm. A very different angle!

As @Tom mentions, microclimate is key. The biggest difference I can make once I have created a well designed enclosure that maintains humidity, it providing plant cover. Hiding under plants is the most natural thing for a tortoise. Lowers stress and protects hydration. Even in the best of enclosures some pyramiding can occur as tortoises remain out and under the light more than they would naturally. Given plant cover, they will use that much more, and grow much smoother.

 

[Neal]

Do you believe that wild Sri Lankan Stars also have pyramiding due to altered habitat or some other human factor? It seems rather unlikely to me based on what I have observed. I have seen photos of Sri Lankan Stars taken in the wild 50-60 years ago which exhibited what would be called fairly severe pyramiding while others did not have the pyramiding.

Also the Star Tortoise illustrated in Sowerby and Lear's book from 1871 is shown with fairly high pyramids. It is hard to imagine that human interference was taking place when that tortoise drawing was done.

Also the South African Psammobates ssp. have fairly pyramided shells as illustrated in that same book. I had some wild caught P. tentorius verroxii in the early 1970's which were quite pyramided.

What do you think? Are some species just naturally pyramided or is there another explanation?

Interesting thoughts and observations.

I have seen a lot of evidence to support some species, and even variants of species, are more prone to pyramiding than others. I could never conclude that it was genetically caused as a fact because I simply don't have the ability to test that variable separately from any different traits or behaviors that an individual tortoise naturally inherits.

More recently, I've thought less that genetics is the inherent reason that some are more prone to pyramid than others. Over the years I've raised a lot of leopards of my own and from other breeders. I can certainly say that some were more prone to pyramid than others despite being raised side by side. The South African type leopards, and those with more of those SA physical traits we generally observe will almost never pyramid, whereas the "eastern" African leopards would be all over the place as far as level of pyramiding despite being raised in identical environments. Even specimens from the same parents showed a lot of variation.

Several years ago I had several different groups of ground hatched leopard tortoises. The space the adults had access to varied a lot, and I had nests all over in wet and dry areas. I observed an impressive difference between the hatchlings from clutches laid in the grass area (soft dirt, cool temperatures and more moisture) from those that hatched from the rocky areas (hard dirt, warmer temperatures and no moisture).

The first two pictures below show the carapace and plastron of one example of the grass area hatchlings:




And an example from the dry group:




Even the plastron development was impacted by the dryer and less nutrient rich nest environment. Both groups had the same parents and the clutches were laid during the same season.

This leads me to believe that the propensity to pyramid is not a genetic factor, but entirely environmental beginning from the egg development process. As we know, tortoise eggs will absorb environmental moisture during development. I have to think that the absence or limited available moisture would impact the tortoise throughout all of its life and not just during the beginning phases of its life. I have kept limited contact with one individual that has one of my dry specimens above, and I know the pyramiding continued despite the humid environments and high-hydration husbandry it was offered.

If I were to apply these observations to what might be observed in the wild, I would think more that pyramided wild tortoises might be that way because of the environment they grew up in, not that they were destined to become that way no matter what. There seems to be some illusion with a lot of hobbyists that wild tortoises are exposed to perfect environmental conditions all the time, but of course that's not the case. Monsoon and rainy seasons are never consistent. Female tortoises don't always lay their nests in the "optimal" locations (as what we might consider optimal), and tortoises don't always behave by keeping themselves in optimal environments.

All this doesn't quite answer the question exactly of whether some species or variants are naturally more prone to pyramid or not. To really test this the entire process beginning with egg incubation would need to be controlled, and I don't want to intentionally expose a control group to "dry" egg development conditions for my own self study.

So anyway, to address the original question posed here, I don't believe diet has anything to do with pyramiding at all. In looking at an old thread of mine that shows down below, I remember asking the question about the origin of dietary impact on pyramiding and there really didn't seem to be much basis for it. The most common response is that the idea of dietary impact was just an assumption made without being thought out or studied intentionally.

 

[Markw84]

Interesting thoughts and observations.

I have seen a lot of evidence to support some species, and even variants of species, are more prone to pyramiding than others. I could never conclude that it was genetically caused as a fact because I simply don't have the ability to test that variable separately from any different traits or behaviors that an individual tortoise naturally inherits.

More recently, I've thought less that genetics is the inherent reason that some are more prone to pyramid than others. Over the years I've raised a lot of leopards of my own and from other breeders. I can certainly say that some were more prone to pyramid than others despite being raised side by side. The South African type leopards, and those with more of those SA physical traits we generally observe will almost never pyramid, whereas the "eastern" African leopards would be all over the place as far as level of pyramiding despite being raised in identical environments. Even specimens from the same parents showed a lot of variation.

Several years ago I had several different groups of ground hatched leopard tortoises. The space the adults had access to varied a lot, and I had nests all over in wet and dry areas. I observed an impressive difference between the hatchlings from clutches laid in the grass area (soft dirt, cool temperatures and more moisture) from those that hatched from the rocky areas (hard dirt, warmer temperatures and no moisture).

The first two pictures below show the carapace and plastron of one example of the grass area hatchlings:
View attachment 393427

View attachment 393430

And an example from the dry group:
View attachment 393428

View attachment 393429

Even the plastron development was impacted by the dryer and less nutrient rich nest environment. Both groups had the same parents and the clutches were laid during the same season.

This leads me to believe that the propensity to pyramid is not a genetic factor, but entirely environmental beginning from the egg development process. As we know, tortoise eggs will absorb environmental moisture during development. I have to think that the absence or limited available moisture would impact the tortoise throughout all of its life and not just during the beginning phases of its life. I have kept limited contact with one individual that has one of my dry specimens above, and I know the pyramiding continued despite the humid environments and high-hydration husbandry it was offered.

If I were to apply these observations to what might be observed in the wild, I would think more that pyramided wild tortoises might be that way because of the environment they grew up in, not that they were destined to become that way no matter what. There seems to be some illusion with a lot of hobbyists that wild tortoises are exposed to perfect environmental conditions all the time, but of course that's not the case. Monsoon and rainy seasons are never consistent. Female tortoises don't always lay their nests in the "optimal" locations (as what we might consider optimal), and tortoises don't always behave by keeping themselves in optimal environments.

All this doesn't quite answer the question exactly of whether some species or variants are naturally more prone to pyramid or not. To really test this the entire process beginning with egg incubation would need to be controlled, and I don't want to intentionally expose a control group to "dry" egg development conditions for my own self study.

So anyway, to address the original question posed here, I don't believe diet has anything to do with pyramiding at all. In looking at an old thread of mine that shows down below, I remember asking the question about the origin of dietary impact on pyramiding and there really didn't seem to be much basis for it. The most common response is that the idea of dietary impact was just an assumption made without being thought out or studied intentionally.

Excellent observations and thoughts, Neal.

That leads to the problem tortoises have in nesting. Too dry an area, and/or too dry a year during incubation - and we have a baby tortoise dead, or started with more propensity to pyramid.

Also, tortoises that have survived the past 1000 years or so in areas that are more temperate have perhaps "learned" to seek cover more reliably. While tortoises in more tropical areas that don't experience cooler nights, aren't as good at that. Stars, "northern" leopards, sulcatas, radiated, redfoot - all "prone to pyramid" but also all more tropical. Put them in an environment that is not tropical and they don't "know" what to do!

 

[Len B]

Yes

From what I read in papers and other sources besides TFO, pyramiding is a multi-factor equation:
1. The primary cause is "too dry conditions": keratin dries out, puts pressure on underlying bones (rather soft in early years) and deforms them.
2. "Too dry" itself depends on complimentary factors:
* with artificial heat sources like basking lamps keratin dries out fast and we mitigate it with rising humidity
* "power feeding" and low calcium diet result in faster growth of softer bone tissue and wider keratin "rings" which put extensive pressure when harden - we mitigate it with higher humidity too.
* genetics - some species are more prone to pyramiding and among one species there is some variation too

We can encounter pyramiding in wild tortoises too (who, presumably, have right diet and only natural sunlight). Some keepers/researchers attribute this to years of draught and deforestation of habitats.

Len, can you share some thoughts on proper diet? (As I understand, you feed a lot of items with high moisture content and sprayed with water to promote internal hydration)

Yes I do feed a very varid diet, I don't spray, I soak the greens in a 5 gallon bucket that has a hole in the bottom
so the water drains out in a few minutes when I cut with the fresh grass and weeds for today's feeding. During the winter when I'm feeding dried greens and rehydrating them I let them soak in a bucket that doesn't have a hole for drainage for good absortation. I don't do this procedure just for the shell but also to stop stones from forming. In another thread I told Barb that I no longer dry leaves for winter feedings. But I've am going to try something new since I have so many leaves that will go to waste. While green I'm going to cut them up with the electric mower and dry them. Then reduce them down and add some to what I usually feed them during the winter months for a more varied winter diet. I also feed opuntia cactus year round. I already have enough grass and weeds dried for next winter but didn't do good with arugula,dead nettle and dandie lions. Haven't seen any dandies for over a month. But I do have a bumper crop of a variety of leaves.