Tortoise project for school!

[TechnoCheese]

I was doing more research, and I found that tortoises put an upwards force on the skeleton when it's growing new keratin on its shell. What if when the tortoise has MBD, or the bones aren't very strong from lack of humidity or too much protein, the bones try to grow with the the upwards force and cause the lumps we call pyramiding. It would explain why after the first few years of life you can't really fix it. What does everyone think?

 

[TechnoCheese]

Does anyone have different theories?

 

[HI Tortoise Rescue]

Well, the humidity here in Hawaii stays fairly constant, with a minimum of 51% & a maximum of 100% (reference https://www.currentresults.com/Weather/Hawaii/humidity-by-month.php), so I consider that as qualifying for "always humid." But more than half of the Sulcatas we rescue have pyramiding, 2/3 of the redfoots have it, & all of the Pardalis are pyramided. I haven't been able to correlate that with what they have been fed, mostly because nearly all people don't even think about mentioning/admitting that they have fed high-protein diets when we ask (which we always do), but I have trouble believing that lack of humidity is a major cause of pyramidization. Before someone asks, no, it's not air-conditioning-related, either, because almost no homes out here have either air conditioning or heating, including my own home, so whatever the temperature & humidity is outside, is what it is inside.

Check out http://www.chelonia.org/Articles/whatcausespyramiding.htm for what I personally consider to be the most-reasonable causes for pyramiding.

Ken

 

[Big Charlie]

I was doing more research, and I found that tortoises put an upwards force on the skeleton when it's growing new keratin on its shell. What if when the tortoise has MBD, or the bones aren't very strong from lack of humidity or too much protein, the bones try to grow with the the upwards force and cause the lumps we call pyramiding. It would explain why after the first few years of life you can't really fix it. What does everyone think?

I read one article that described pyramiding as when scutes grow upwards instead of outwards. Normal growth should be horizontally, pyramiding is when scutes grow upwards, with the centers having the most upward growth.
You can't fix it because when you fix the conditions that cause pyramiding, the new growth might be even and horizontal, but you can't make those parts that didn't grow vertically catch up to those that did (the centers of the scutes).

Many people believe the greatest risk to developing pyramiding is in the first few years. Once you get past that time and your tortoise remains smooth, it will continue to grow mostly smooth no matter what kind of conditions you provide. It would be interesting to see if you can find anything to prove this.

 

[TechnoCheese]

I'm a little late, but thanks!

 

[KevinGG]

I had worked with Dr. Paul Gibbons of the Behler Chelonian Center on conducting a pyramiding study. Unfortunately, things didn't work out with scheduling, but I can share some thoughts from our conversations. There are no scientifically accepted studies on pyramiding. So, echoing other forum members, no one truly knows the cause. Humidity seems to have become the definitive answer on the forum and many members provide great examples of smooth tortoises raised in these conditions. But I've also seen many cases where tortoises were kept humid and did develop pyramided shells. The best example I have is at the BCC. They hatch out huge numbers of radiated tortoises every year and many of them are kept in their large greenhouse that is kept at very high humidity for forest species, yet most do pyramid. There are just too many variables to decide what the cause is without a large study(we had planned on using ~80 sulcata tortoises, provided and raised by @Tom, monitored from egg to juveniles)
Regarding sulcatas, there is no literature on how young sulcatas grow. If hypothesis was humidity was key factor, some questions we had: Do they stay in the humid hide all day, all year? If so, how do they regulate their temperatures? Where do they get food, water? While humidity may be a factor, our guess was that it wasn't the only factor. The idea that seemed most interesting was that water directly on the shell was the main factor in preventing pyramiding. This also seemed to make sense in the context of wild tortoises as it is likely that, at the very least sulcatas, come in contact with dew on a regular basis. Of course humidity could contribute. Or perhaps they only work in tandem, which would explain why certain keepers experience better results. And of course it could be caused by more than just those two. What seems true(at least from what I've seen), is that the combination of proper husbandry(diet, lighting, temps), humidity, damp substrate, and daily water directly on the carapace ensures smooth growth. I know many of you have hypothesized similarly. Don't want to seem like I'm presenting this for the first time. Interested in hearing people's experience with this.

About the school study: You could use just two tortoises(guessing you can't use more) Give them identical enclosures. Need to be separate of course. You'll need to pay attention to everything that you do. You don't want any more variables than the ones you're testing. That also means you'll have to monitor as much as you can(temps, humidity, weight, shell growth, etc) Use identical diet, substrate, lamps, temps, etc. Only two variables would be humidity and misting of shell. Another way you could do it is keep them in same enclosure with a divider so humidity is identical and have only variable be misting of shell.

These wouldn't be scientific studies, but you should get interesting results for your class. For an idea on how to measure pyramided growth, look at this study: http://www.amazonreptile.com/tortoisepyramiding.pdf This isn't a respected study in the scientific community but should give you some ideas. If you have questions along the way, feel free to PM me.