Size?

[Jami]

Hi there,

Is there a "size chart" for Hermann's anywhere? I'm wondering how big a 3 month old Hermann's should be? How much growth can we expect to see in the next 2 years? How big at 6 months, 1 year, 2 years?

Thanks!

 

[ascott]

https://sites.google.com/site/tortoiselibrary/health-and-medical/healthy-weight-and-size

 

[Jami]

https://sites.google.com/site/tortoiselibrary/health-and-medical/healthy-weight-and-size

Thanks! I thought I did a good search, but maybe I gave up too soon! I appreciate the link!

 

[Jami]

This one says not for hatchlings too tho. I was just wondering average sizes at certain ages. But thanks.

 

[ascott]

I was just wondering average sizes at certain ages

You know, there are a few things you can check on to see if the tort in your care is doing well....remembering that rarely will two torts ever grow at the same pace...they may end up at the finish line relative to one another...but the race will be different....

Is the tort active?
Is the tort hydrated?
When you lift the tort, is it solid and heavy, relative to overall size?
Is the tortoise eating well, and show what we humans see as excitement when it is chow time?
Does the tort seem to be falling into a routine?

If you have positive outcomes to these points, then I would be fine with their individual growth rates....
(if you are housing a pair, this changes a bit--there should not be significant difference in food excitement nor activity level, as there then may be a subtle bullying issue).

 

[THBfriend]

All those ratios (Jackson, Donoghue, Tortoise BMI, ...) might be suitable as rough guidelines, rules of thumb, but nothing more. If you look at those formulas, you'll see that they use the straight carapax length (SCL) cubed. Any mathematician or physicist can tell you that this makes those formulas very sensitive to even slight changes of the SCL value, be it from inaccurate measurements or from natural variations of a tortoise's shell. Those errors manifest most strongly for small tortoises (e.g. hatchlings), but also for larger adults.

Quick example: let's assume I have an adult tortoise with an SCL of 18.7 centimeters and a weight of 1250 grams.
Jackson ratio says 0.191 (normal, but below the "optimum" for hibernation of 0.21)
Donoghue says the tortoise should weigh 1249 g.
Tortoise BMI says 1.001 - perfect.

But what if my measurement was off by a single millimeter, which is almost nothing (0.04 inches)? For an SCL of 18.8 cm and 1250 g:
Jackson ratio says 0.188 (still normal, but lower than before)
Donoghue says the tortoise should weigh 1269 g.
Tortoise BMI says 0.985 - "a little underweight. Review and correct cares and diet as appropriate"

The assumption that the tortoise BMI has to be at precisely 1.0 is clearly ridiculous. An SCL variation of 1 mm or a bowel movement can throw the results into a different category. Those formulas also assume a perfect shell. If you have a rescue tortoise with a flattened or otherwise deformed shell, the formulas will never apply, simply because of the different shell volume.

Like Angela said, different tortoises grow at different rates. It depends a great deal on what and how much you feed them and whether or not they hibernate/brumate. And even if those factors are nearly identical, there's still variation between individuals, as can be seen on the weight development chart I posted here.

 

[Jami]

Thank you both! I think he's doing well, I just wasn't sure how big he could be in a few months. Thanks!