5 Year Member
Platinum Tortoise Club
- Jan 17, 2012
- Location (City and/or State)
- Sacramento, CA (Central Valley)
I just posted this on anther thread, but as it developed, I thought the title of that thread took away from the message and was best in a thread of its own titled appropriately.
I have come to believe through all my trial and error, all the things I read and study, all the experiments done - heat, no heat, night heat, no night heat, fast growth, slow growth, higher protein, more calcium, better UVB, on, and on, and on - all to me only fit one basic take on this. I can't imagine a variable that hasn't been tried, yet all do fit one conclusion. Pyramiding is seen when you have high metabolism triggered WITHOUT humidity. If you give the tortoise higher heat and more food, without humidity, you will get Pyramiding.
If I think about the tortoise in its natural environment, they ENDURE periods of food scarcity, and hot, dry weather. They basically stop growing and estivate during these periods to survive - waiting for the time to thrive. When the monsoons come, they have ample food with the rains and humidity. They grow in those conditions. They don't grow in food-scarce, dry conditions. It's really logical - food is available when it is wetter allowing the food to grow. So warm + humid = grow time. In dry times, the food dries up, and tortoises stop growing. It's when we create an artificial condition they would never see naturally in their home environments that we see pyramiding. We provide ample food and heat & UVB in DRY conditions. We get their metabolism going, yet without one key ingredient - proper hydration. So they grow, but don't grow naturally.
Sulcatas seem to follow this pattern the most strictly. It seems where they come from, when it dries up, there is no water available, nor food, so they go in a real slow or no growth mode in those dry times. If you look at leopards and stars, some seem get pyramided in the wild. But they also come from areas where it may end up a dry year, but water sources may linger longer into dry periods, and I believe you would see tortoises (especially growing their first few years) through abnormally dry years - actually finding food and growing in dry conditions - and pyramiding.
3 1/2 months ago now I got a group of Burmese Stars from the Behler Center. Their philosophy is to purposely slow grow their Star tortoises a bit along the belief that fast growth would lead to more pyramiding. I got them and they were pretty significantly pyramided and quite small for their age. So despite purposeful slow growth in conditions meant to more mimic a natural environment temperature wise - They pyramided. The humidity in their enclosures was always quite low. They do keep other species in greenhouses with controlled humidity, but the Burmese are kept drier. The average weight of the goup when they arrived was 454.2 grams despite being just over 5 years old. I have since convinced them the monsoon season has finally arrived, with a closed chamber I posted my build in that was a basic copy of @Tom 's chambers. So in 3 1/2 months the group had now averaged adding 301.8 grams! So the average for the group was going from 454 g (in five years) to 756 g in 3 1/2 more months. So, I grew them too fast and they will surely pyramid after 5 years of a set growth pattern - right? NO! All the new growth is coming in flat. Here's a picture I just went out to take of the growth pattern you can see in one of them...
For me this continues to confirm that fast growth has nothing to do with pyramiding. This study this thread is about says high heat may cause pyramiding. While actually, my closed chamber is in my second garage that the past several weeks has been close to 93 dropping to 80 at night. The chamber constantly struggled to stay in the low 90's as I had to put the basking lights on a separate thermostat to turn off at 90 to avoid overheating. Their nighttime temps averaged 85. Despite this higher heat, faster growth, AND 5 years of a pyramiding growth pattern in a drier environment - I saw immediate change in growth pattern and what looks to be a total stop to the pyramiding. I did not expect to see it so immediate!
For me - I'm still convinced more than ever, if they grow - it must be humid!
After posting that, @mark1 posted a reply mentioning what he had learned in a study about the growth of keratin in horns in cattle. He referenced that article - I read it and a the light bulb went on in my head...
NOW THAT'S INTERESTING AND SHOWS CAUSE FOR PYRAMIDING!!!
According to that study, keratin, while forming, if exposed to dry conditions will become more stiff and resistant to additional swelling if later exposed to water, while hydrated keratin will swell more resulting in a thicker layer.
I just seems to me all this mystery about pyramiding causes could be something simple. What would fit all scenarios is that the keratin as it fills in over new growth areas, will stiffen, and become resistant to filling in in a thicker layer above, yet add additional keratin below. That would cause downward growth with successive layer. As the bone growth beneath (especially in younger tortoises) is much more pliable, it would follow this growth pattern. However when kept in a moist environment, the keratin retains it ability to swell and add volume to the new scute in a more even, top to bottom, profile. Thus an even, straight growth pattern.
Everything would fit this... extremely slow growth would not pyramid and the keratin layer is barely filling in over new bone and this effect does not have a chance to happen. However, whenever there is faster growth, the larger new bone area we all see as those white lines in many species, will require faster keratin growth as well to follow. If in a dry environment, this effect will then cause the keratin to push the bone downward as the top layer of keratin becomes stiffer much faster than the bottom of the keratin. Through measurements over the years I had always believed pyramiding was not an UPWARD growth of the scute, but a downward growth of the seams. A pyramided tortoise most always measured just as tall to the top of the pyramid as a smooth tortoise is to the top of the smooth shell. So valleys are forming, not peaks.
Every scenario we have seen of pyramiding vs no pyramiding, including this study, exactly fits this proposed cause.
A few more responses were posted, and I explained my hypothesis further. Asked if that meant I was proposing "the shell needs moisture to grow properly in the up and out direction? That without the moisture it may stiffen too quick, causing the growth to pyramid?" I responded...
Basically, yes. But I'm proposing an actual CAUSE.
@Tom showed so well in his experiments that growth in a very humid environment resulted in virtually no pyramiding, However, we still don't know what CAUSES that. @deadheadvet mentions above his belief that temperature is a factor that drier air is a more stable temperature. Yet I personally have grown dozens of tortoises in very controlled stable temperature environments, and only when humidity was increased, and still using the exact temperatures as before, did I see a dramatic decrease in Pyramiding. For decades fast growth was also stated as a factor. Yet again I personally tired that, and did different diet experiments, yet only now see consistent and repeatable results of no pyramiding if humid - despite very fast growth, and different diets.
deadheadvet's assertion that pyramiding obsession is way too extreme has merit. The overall health is of chief concern. However, Everyone, including deadheadvet take pride in showing off the beauty of the animals we raise. All of us loving to post prideful pictures. That is a great satisfaction of raising tortoises, or any animal successfully. A smooth, non-pyramided shell, I believe, is a very desirable and sought after result. Although in a vast majority of the cases it is cosmetic, I personally see it as a sign of great husbandry. Not to eliminate it, but to minimize it.
In extreme cases, I believe some may actually be bone problems. But I don't feel we are talking about that here. It's the "cosmetic" deformity of the shell growth I feel is reflected in husbandry techniques.
So many of us have spent decades experimenting with FACTORS that will contribute to or minimize pyramiding. But what is the CAUSE metabolically? I'm 1proposing that the growth of the scute above the bone is the primary cause of pyramiding. The study Mark! referenced showed that Keratin acts and forms differently in a dry vs moist environment. When dried the fibers actually form differently and become more stiff and resistant to a swelling that occurs with keratin that has not been excessively dried. SO...
I'm proposing that in dry environments, and very slow growth, the keratin as it forms at the edges of the scutes does so in a fairly uniform manner. But when moderate to fast growth occurs - the faster spread of keratin, exposed to dry conditions, will cause the top to stiffen, and not continue to swell as it continues to form, while the bottom of the new scute keratin continues to grow in a thicker way. This pressure is exerted on the bone below and causes the new scute seam to be lower than the previous seam. In a humid environment, the keratin as it spreads, does so much more evenly, with stiffness and swelling equal top and bottom - and grows straight.
The more I think this over, the more it makes sense to me. I went back and reread Tom's "the End of Pyramiding" thread. It answers all the issues and questions always posed on this contentious subject. Many always seen to refute the humidity, or say there is no scientific basis - based on the way metabolically bone grows. They're right -its not the bone affected - its the scute affecting the bone! Just a braces can straighten teeth in a jaw or a corrective helmet's gentle pressure can straighten the growth of an infants head. Or they partially accept it and say it is complex and many factors come into play. Yet we see time and again examples of smooth growth with humidity no matter which of the other "contributing factors" are left out in the care of the tortoise. Smooth with inadequate D3, Smooth with no sunlight, smooth with fast growth, food with inadequate calcium and even metabolic bone disease - yet smooth! Yet we never see smooth without humidity somewhere in the equation. It also speaks directly to the issue I have noticed, and Tom and others have mentioned but there was never a WHY... How come tortoises seem to be very resistant to pyramiding once they reach a certain size? Well, it would make sense that as the tortoise ages, it reaches a point where the underlying bone hardens enough to resist the pressure the scute applies.