How much should a Redfoot weigh?

[RosieTortoise]

I introduced myself and Rosie here. She is still at the pet store and I'm still caring for her there. Hopefully my husband will okay bringing her home soon!

I know that she is severely underweight. I did some research and found that a tortoise her size should weigh three pounds! Is that right? She is about 6 inches from one end of her shell to the other.

Aside from wondering how much she should weigh, how can I help her up her weight. She's only .75 lbs. and I can't seem to get her to gain. I know she might be dehydrated and I give her lots of baths, but I'm concerned. I really think once I get her into an appropriate enclosure she will start gaining and just improve in general. I'm hoping I can bring her home tomorrow.

 

[lisa127]

With proper hydration she will show a weight gain. I would say at 6 inches scl she should be at least a couple lbs. Once she's getting proper care weigh her weekly and see if she starts to gain.

 

[Anyfoot]

I'm pretty sure this formula is in the book 'Redfoot Manual'.

SCL(cubed) in cm x0.191 = weight in grams.
This seemed to be accurate with mine to about 10%.

 

[RosieTortoise]

I'm pretty sure this formula is in the book 'Redfoot Manual'.

SCL(cubed) in cm x0.191 = weight in grams.
This seemed to be accurate with mine to about 10%.

Awesome! Thanks! I will measure her today.

 

[Pearly]

Hi Rosie, while formulas are great to have for reference, I'd caution you to not get too preoccupied with "the numbers". In my view, torts like people are all different. It is good to kinda know how the growth curve goes in the tort baby or juvenile, but there will always be exceptions. Example: i think my 2 juvies are way too big/heavy for their age, but somehow I think that they will slow down and their tort friends will be catching up with them. What people on here have taught me as basic rule of thumb is that when you pick up your tort, he/she should feel solid, like a rock! One of my babies was light as feather when we first got them and he was not interested in food at all. You hear those stories of sickly hatchlings being sold to people all the time. After 19 months of intense research and relentless trials/errors, I can summarize it like this: FEED, FEED, FEED! 3-4 times a days! Put them in front of their food! Don't wait for them to come out and eat if they are already compromised. They won't do it. Keep them nice and warm day and night and humid, temps never lower than 80F! Humidity at least 80%. Give nice warm bath not hot but warm enough for their bodies to warm up to at least 85F in water bcs at this temp their metabolism will kick up, they'll pee/poo and likely be interested in eating right after such bath. Provide opportunity to exercise, but safety first! Their "gym" has to be tortproof, they are know to ingest nonedible/or poisonous stuff, keep predators (dogs) away, keep them from climbing heights, or dangers of falling on their back when unsupervised... things like that. Safe, warm, hydrated, exercised little tort when offered variety of food items of different color, texture, scent, flavor... is bound to catch on which is my wish for you. Best of luck! Keep us posted

 

[Redstrike]

I'm pretty sure this formula is in the book 'Redfoot Manual'.

SCL(cubed) in cm x0.191 = weight in grams.
This seemed to be accurate with mine to about 10%.

Using math to quantify and objectively assess and evaluate whether a tortoise is underweight is simple with the equation outlined above.

Here is a thread that demonstrates ranges of tortoise body mass indices (BMI) to evaluate whether your tortoise is truly under or over weight given it's Straight Carapace Length. http://www.tortoiseforum.org/threads/tortoise-weight-formula-tbmi.38420/

In case others are wondering but don't read the linked thread (or there's an issue there), the idea is that the BMI follows a distribution where the Mean = 1. One or two standard deviations from this mean puts you into the other categories:

- 0.66 or lower: There is less than a 2.5% chance that this tortoise is healthy at this weight. It is probably very dehydrated and/or underfed and should be seen by a vet.
- 0.66 to 0.83: There is only about a 15% chance that this tortoise is healthy at this weight. It is probably dehydrated and/or underfed and needs appropriate care.
- 0.83 to 1.00: This is a normal range, but statistically a little underweight, which may signal mild dehydration and/or being underfed. Review and correct cares and diet as appropriate.
- 1.00 to 1.16: This is a normal range, but statistically a little overweight, which may signal mild overfeeding. Review and correct cares and diet as appropriate.
-1.16 to 1.33: There is only about a 15% chance that this tortoise is healthy at this weight. It is probably at least somewhat obese and needs appropriate care.
1.33 or over: There is less than a 2.5% chance that this tortoise is healthy at this weight. It is probably obese and needs appropriate care.


Because tortoises are poikilotherms ("cold blooded") they require far fewer calories than mammals and birds. I fed my four hatchlings once/day without issues - though I too brought them to the food until they started catching onto the process.

Is your tortoises eating regularly? What type of water dish are you using? What is your humidity at? Excuse me if you've already outlined these questions previously (feel free to steer me to that conversation) I'm not on here as often as I'd like.

 

[Yvonne G]

Every time I read the title of this thread I read it as, "How much should a redfoot weigh if a woodchuck could chuck wood?"

 

[Pearly]

Every time I read the title of this thread I read it as, "How much should a redfoot weigh if a woodchuck could chuck wood?"

Bwahahaha! Right there with you!

 

[lisa127]

I'm pretty sure this formula is in the book 'Redfoot Manual'.

SCL(cubed) in cm x0.191 = weight in grams.
This seemed to be accurate with mine to about 10%.

This formula does not work for me. Maybe I can't do math!

 

[Anyfoot]

This formula does not work for me. Maybe I can't do math!

What is the SCL of your tortoise Lisa?

 

[lisa127]

What is the SCL of your tortoise Lisa?

Between 9.5 and 9.75 inches. It's hard to get it really accurate.

 

[Anyfoot]

Between 9.5 and 9.75 inches. It's hard to get it really accurate.

Lisa, I've played with this formula before and I accepted a 10% error in my own mind. Since then I've gained quite a few more torts, I'll have to use this on some of those to see what the outcome is, whatever the outcome I won't be worrying, if it feels heavy it's OK if not it needs some food. I know I have one male that is extremely light in weight. He's slowly putting weight on now. I've had him about 4 months now.
Anyway, I'll put down your sums for both 9.5 and 9.75" SCL. See if you can get same values on your calculator. I cant write down the cubed symbol, which is a small 3.
The figures in brackets represent CUBED.

9.5" x 2.54 = 24.13cm.
(24.13 x 24.13 x 24.13) x 0.191 = 2683g

9.75" x 2.54 = 24.765cm.
(24.765 x 24.765 x 24.765) x 0.191 = 2901g

 

[lisa127]

Lisa, I've played with this formula before and I accepted a 10% error in my own mind. Since then I've gained quite a few more torts, I'll have to use this on some of those to see what the outcome is, whatever the outcome I won't be worrying, if it feels heavy it's OK if not it needs some food. I know I have one male that is extremely light in weight. He's slowly putting weight on now. I've had him about 4 months now.
Anyway, I'll put down your sums for both 9.5 and 9.75" SCL. See if you can get same values on your calculator. I cant write down the cubed symbol, which is a small 3.
The figures in brackets represent CUBED.

9.5" x 2.54 = 24.13cm.
(24.13 x 24.13 x 24.13) x 0.191 = 2683g

9.75" x 2.54 = 24.765cm.
(24.765 x 24.765 x 24.765) x 0.191 = 2901g

Well, he weighs 2305 grams (5.1 lbs.) So he's underweight? He feels very heavy!

 

[Anyfoot]

Well, he weighs 2305 grams (5.1 lbs.) So he's underweight? He feels very heavy!

I'm not convinced any formula can work accurately. It's only a guide. Thinking back I think the worst case for me was 13% out.
I'll do some measuring when I get the chance.
What I don't understand is,
Males are concave and females are not.
Females can be carrying eggs.
I have 2 torts the same SCL, the old one has a super thick plastron and carapace, all these things are variables.

 

[Redstrike]

I'm not convinced any formula can work accurately. It's only a guide. Thinking back I think the worst case for me was 13% out.
I'll do some measuring when I get the chance.
What I don't understand is,
Males are concave and females are not.
Females can be carrying eggs.
I have 2 torts the same SCL, the old one has a super thick plastron and carapace, all these things are variables.

This equation was likely formed using a linear regression for 76 individuals representing multiple turtle and tortoise species.

Because it used different species and a small sample size, it is unlikely a representative sample for one particular species.

It could be conducted again for one species and partitioned by sex but it seems to do a decent job answering the healthy weight question.

 

[Redstrike]

Well, he weighs 2305 grams (5.1 lbs.) So he's underweight? He feels very heavy!

Assuming your tortoise is 6.75", you have to divide your observed weight (2305) by the expected/calculated weight. 2305/2901= 0.795.

This puts your Body Mass Index at slightly lower than expected (1), but not drastically so. The difference could be water (needs hydration) or simply error in the fit of this regression to your tortoise.

 

[Anyfoot]

This equation was likely formed using a linear regression for 76 individuals representing multiple turtle and tortoise species.

Because it used different species and a small sample size, it is unlikely a representative sample for one particular species.

It could be conducted again for one species and partitioned by sex but it seems to do a decent job answering the healthy weight question.

So you think it's possible to make a more accurate formula for individual species, like our redfoots. Sounds like a mammoth task, maybe even split northern from Brazilian.
Sounds like a job for you Mr redstrike. Is it doable.

 

[Redstrike]

So you think it's possible to make a more accurate formula for individual species, like our redfoots. Sounds like a mammoth task, maybe even split northern from Brazilian.
Sounds like a job for you Mr redstrike. Is it doable.

Very doable. Just need SCL, weight, locale, and sex for specific tortoise species.

It would be more interesting to me to quantify the difference between a species-specific linear model versus the current model.

 

[lisa127]

Assuming your tortoise is 6.75", you have to divide your observed weight (2305) by the expected/calculated weight. 2305/2901= 0.795.

This puts your Body Mass Index at slightly lower than expected (1), but not drastically so. The difference could be water (needs hydration) or simply error in the fit of this regression to your tortoise.

9.75 inches, not 6.75 inches. But still applies as 2901 was determined on the 9.75 inches. He could be closer to 9.5 though.

 

[RosieTortoise]

Hi Rosie, while formulas are great to have for reference, I'd caution you to not get too preoccupied with "the numbers". In my view, torts like people are all different. It is good to kinda know how the growth curve goes in the tort baby or juvenile, but there will always be exceptions. Example: i think my 2 juvies are way too big/heavy for their age, but somehow I think that they will slow down and their tort friends will be catching up with them. What people on here have taught me as basic rule of thumb is that when you pick up your tort, he/she should feel solid, like a rock! One of my babies was light as feather when we first got them and he was not interested in food at all. You hear those stories of sickly hatchlings being sold to people all the time. After 19 months of intense research and relentless trials/errors, I can summarize it like this: FEED, FEED, FEED! 3-4 times a days! Put them in front of their food! Don't wait for them to come out and eat if they are already compromised. They won't do it. Keep them nice and warm day and night and humid, temps never lower than 80F! Humidity at least 80%. Give nice warm bath not hot but warm enough for their bodies to warm up to at least 85F in water bcs at this temp their metabolism will kick up, they'll pee/poo and likely be interested in eating right after such bath. Provide opportunity to exercise, but safety first! Their "gym" has to be tortproof, they are know to ingest nonedible/or poisonous stuff, keep predators (dogs) away, keep them from climbing heights, or dangers of falling on their back when unsupervised... things like that. Safe, warm, hydrated, exercised little tort when offered variety of food items of different color, texture, scent, flavor... is bound to catch on which is my wish for you. Best of luck! Keep us posted

The poor baby feels like a wiffle ball.