How they grow .. and why..
- Thread starter Redfoot NERD
- Start date
That's not well said.. he's twisting the issue and the point of this post. We are talking about the fact that some in the animal kingdom rely on their diet for D3.. and some rely on sunshine / UVB.. and some rely on both!!!
If anyone will objectively look at the growth pics of mine.. they will notice that some of the pics were taken outside. Does anyone honestly think that those featured never have seen sunshine?
My only concern is that the "universal" caresheet creaters have painted all tortoises with the same brush.. and no tortoise will ever rely on any form of animal protein in their diet.
No other comment GingerLove ...
Morning Mr redstrike
Its not about sticking a tort in a dark enclosure to raise them, I'm assuming there are other health benefits from the sun too, maybe it lifts testosterone levels for example.(MAYBE)
For me it's just about learning facts. Of course the sun has benefits regarding D3, but can and do they get it from the diet ASWELL. Nobody will say yes or no, they must do, hasn't nerd proved that.
It's safe to say in my part of the world compared to Carl's that his will receive far more benefit from the sun, I have to rely more on artificial UVB for long periods. So if it was proved that a 2nd source of D3 intake was available (diet) it would make me feel more confident in raising healthy reds, and I would feel I could push this information on to new keepers in the uk, and hopefully start seeing some healthy redfoots on this side of the pond.
Mammals-reptiles, I get what your saying about apples-oranges. It was merely an example of how the animal world adapts. Im suprised nobody mentioned uv deflection tbh.
One last question to all then I'm going to leave this thread alone.
What are your opinions regarding hatchlings eating bugs/worms etc in the wild.
Do they eat them or not?
Yes, I'm sure some of the D3 could be ingested by hatchling/juvenile redfoots' diet.
I prefer objectivity when "proving" something. The scientific method is about as objective as you can get. I have yet to see a controlled experiment "proving" D3 is absorbed from the diet in redfoots. Instead we are assuming this is the case. All I found on diet & D3 in reptiles was on panther chameleons (http://www.jstor.org/stable/10.1086/597525?seq=1#page_scan_tab_contents). Good article attached on herman's tortoise.
Vitamin D is one of those that is fat soluble, so it's generated and can be stored for later use.
Big Ol Tortoise
Well-Known Member
so do box turtles need a basking light?
So, I've been thinking on the subject of vitamin D3 and the sources for the past days and this is what I believe.
I think it is dangerous to advice on not using a source of UVB in redfoot tortoises, especially for keepers who house their redfoots inside for most of the year. Here is why:
In nature they probably rely on a combination of D3 production in response to UVB light, and D3 from food sources. We do not know at the moment what is the most important source. However:
1. UVB is also present in shaded areas, and wild redfoots are known to bask. Many people argue that because redfoots love shade, they do not come into contact with UVB rays. However, UVB rays are also present in shaded areas [https://www.ncbi.nlm.nih.gov/pubmed/16005208]. Next to this, one of our other members describes that wild redfoots are seen to go to sunny areas (see above) and this behavior is also seen in captive redfoots (see above also). I believe many members that keep their redfoots outside fulltime or parttime are therefore unconsciously providing UVB light.
2. Relying on dietary vit D3 alone poses health risks. There are several reasons I say this:
- We do not know the exact requirements of our tortoises. Do they need a lot of vit D3 because they have more calcified body parts then most animals (shell and bones)? Or are they really efficient with their D3 and do they only need a bit? What happens when the animal is growing or laying? I wouldn't know.
- We do not know the efficiency of the uptake from the diet. We know there are probably differences between different reptiles/animals, based on there living conditions (see above). But for redfoots this is mostly unknown, as far as I know.
- We do not know exact intake of vit D3 from the diet, because the D3 content of many food sources is unknown. Some say mushrooms contain a large amount of D3. But is this also the case for our commercially grown mushrooms? This seems not to be the case [http://www.thehealthyhomeeconomist.com/vitamin-d-in-mushrooms/].
These three reasons could easily lead to under dosage of vit D3 (potentially leading to MBD) or over dosage of vit D3 (potentially leading to for example calcification of soft tissues such as lungs). As I said earlier, no over dosage can occur with vit D3 produced in reaction to UVB light [https://en.m.wikipedia.org/wiki/Hypervitaminosis_D#Suggested_tolerable_upper_intake_level_.28UL.29]. And, when using a correct diet and UVB source (no old UVB light for example) no under dosage will occur either.
I would therefore always recommend to use a UVB source. This can be either natural sunlight, or an artificial UVB light. I think many members here who believe they are not providing UVB are still doing so by keeping their redfoot outside for a large part of the year. Too bad this is not possible for all keepers (such as myself) due to weather conditions. Because most keepers feel their redfoot doesn't like bright lights, I would generally recommend to use a tube UVB light for indoor housing and/or provide a lot of shade. However, because I see my redfoot bask under the MVB every day on multiple occasions I have no reasons to change this setup in my case. This could depend on the personality of your tort maybe. This is way I stated earlier there are more "right" ways to keep a redfoot.
I think it is dangerous to advice on not using a source of UVB in redfoot tortoises, especially for keepers who house their redfoots inside for most of the year. Here is why:
In nature they probably rely on a combination of D3 production in response to UVB light, and D3 from food sources. We do not know at the moment what is the most important source. However:
1. UVB is also present in shaded areas, and wild redfoots are known to bask. Many people argue that because redfoots love shade, they do not come into contact with UVB rays. However, UVB rays are also present in shaded areas [https://www.ncbi.nlm.nih.gov/pubmed/16005208]. Next to this, one of our other members describes that wild redfoots are seen to go to sunny areas (see above) and this behavior is also seen in captive redfoots (see above also). I believe many members that keep their redfoots outside fulltime or parttime are therefore unconsciously providing UVB light.
2. Relying on dietary vit D3 alone poses health risks. There are several reasons I say this:
- We do not know the exact requirements of our tortoises. Do they need a lot of vit D3 because they have more calcified body parts then most animals (shell and bones)? Or are they really efficient with their D3 and do they only need a bit? What happens when the animal is growing or laying? I wouldn't know.
- We do not know the efficiency of the uptake from the diet. We know there are probably differences between different reptiles/animals, based on there living conditions (see above). But for redfoots this is mostly unknown, as far as I know.
- We do not know exact intake of vit D3 from the diet, because the D3 content of many food sources is unknown. Some say mushrooms contain a large amount of D3. But is this also the case for our commercially grown mushrooms? This seems not to be the case [http://www.thehealthyhomeeconomist.com/vitamin-d-in-mushrooms/].
These three reasons could easily lead to under dosage of vit D3 (potentially leading to MBD) or over dosage of vit D3 (potentially leading to for example calcification of soft tissues such as lungs). As I said earlier, no over dosage can occur with vit D3 produced in reaction to UVB light [https://en.m.wikipedia.org/wiki/Hypervitaminosis_D#Suggested_tolerable_upper_intake_level_.28UL.29]. And, when using a correct diet and UVB source (no old UVB light for example) no under dosage will occur either.
I would therefore always recommend to use a UVB source. This can be either natural sunlight, or an artificial UVB light. I think many members here who believe they are not providing UVB are still doing so by keeping their redfoot outside for a large part of the year. Too bad this is not possible for all keepers (such as myself) due to weather conditions. Because most keepers feel their redfoot doesn't like bright lights, I would generally recommend to use a tube UVB light for indoor housing and/or provide a lot of shade. However, because I see my redfoot bask under the MVB every day on multiple occasions I have no reasons to change this setup in my case. This could depend on the personality of your tort maybe. This is way I stated earlier there are more "right" ways to keep a redfoot.
I agree. UVB is certainly present in shaded areas. I got my worst ever sunburn as a teenager under a tree on a cloudy day in mid summer (I learned my Mum was right about sunscreen)
Forest species will be exposed to UVB in the wild and those in captivity may not need much, but I'd not be prepared to recommend none to anyone.
More excellent information. Thanks.
This is great, thank you.
Just some thoughts and observations...I'll admit that much of this conversation regarding D3 uptake, fat soluble or not, UVB/UVA requirements for D3 uptake, is there D3 in bugs?, D3 this and D3 that, have my head spinning. Frankly, much of the science that the friends of this forum have included in their responses is good-- but over my head. I have no problem admitting it either...never even heard of D3 until a few years ago.
But I'll offer this caution that I recently read in a book about bonsai culture..."The challenge in trying to separate the many existing bonsai ( or tortoise) myths from horticultural (or biological) facts is difficult. Myths start from a false premise. Confusion is the result" Larry Morton author of Modern Bonsai Practice.
Morton also adds that misinformation or misunderstandings are often simply repeated by someone who was misinformed by someone else who was misinformed in the past, and then over time the misinformation becomes 'fact' in people's minds.
I've been keeping red-footed tortoises since I was in Jr. High School in 1973. I've read everything I could get my hands on regarding these animals. You know what? I seen a random comment in an old book, or a finding in the stomach of a wild tortoise get turned into absolute 'facts' about the needs of the animal. Over time I've read on this and other forums, or in recent magazine articles, or books about how red-footed tortoises must have animal protein.
Where did this begin? Because one study found snake scales in the feces of a tortoise in northern Brazil or another animal that ate a dead lizard? Or one tortoise pooped some bird feathers? These findings have been repeated and repeated to death to the point where some keepers insist that red-footed tortoises are carnivorous.
This has lead to much hand-wringing about which cat food, or cooked chicken or mice that a captive red-foot must have. Or others inferring that since red-foots need 'so much protein' it must because they are getting D3 from it. It's laughable.
OK, they do really go for animal parts and seem to do quite well when they get some protein in their diets. But how far does one take this? I'll tell you this, I almost NEVER feed my tortoises meat, or cat food-- and certainly not mice. At least not anymore, although I did many years ago.
Here's something else...other tortoise species that are considered to be vegetarian (or mostly vegetarian) have been discovered in the wild eating some pretty interesting things. For example I've read or have been told of leopard tortoises eating hyena poop (try to obtain that for your animals) and dead elephant parts, and wild Aldabra tortoises eating...other Aldabra tortoises that had died! Hermann's tortoises have been found in the wild eating small dead animals too. Should I then conclude that these species require animal protein in their captive diet?
For me the key is common sense. Separating the good information from the misinformation. What is an acceptable, reasonable practice and what is overkill?
Fortunately, our animals are tough and can appear to do quite well while under widely varying captive practices. If it's working for you keep doing it but don't insist that you've unlocked the secret door to successful tortoise keeping.
But I'll offer this caution that I recently read in a book about bonsai culture..."The challenge in trying to separate the many existing bonsai ( or tortoise) myths from horticultural (or biological) facts is difficult. Myths start from a false premise. Confusion is the result" Larry Morton author of Modern Bonsai Practice.
Morton also adds that misinformation or misunderstandings are often simply repeated by someone who was misinformed by someone else who was misinformed in the past, and then over time the misinformation becomes 'fact' in people's minds.
I've been keeping red-footed tortoises since I was in Jr. High School in 1973. I've read everything I could get my hands on regarding these animals. You know what? I seen a random comment in an old book, or a finding in the stomach of a wild tortoise get turned into absolute 'facts' about the needs of the animal. Over time I've read on this and other forums, or in recent magazine articles, or books about how red-footed tortoises must have animal protein.
Where did this begin? Because one study found snake scales in the feces of a tortoise in northern Brazil or another animal that ate a dead lizard? Or one tortoise pooped some bird feathers? These findings have been repeated and repeated to death to the point where some keepers insist that red-footed tortoises are carnivorous.
This has lead to much hand-wringing about which cat food, or cooked chicken or mice that a captive red-foot must have. Or others inferring that since red-foots need 'so much protein' it must because they are getting D3 from it. It's laughable.
OK, they do really go for animal parts and seem to do quite well when they get some protein in their diets. But how far does one take this? I'll tell you this, I almost NEVER feed my tortoises meat, or cat food-- and certainly not mice. At least not anymore, although I did many years ago.
Here's something else...other tortoise species that are considered to be vegetarian (or mostly vegetarian) have been discovered in the wild eating some pretty interesting things. For example I've read or have been told of leopard tortoises eating hyena poop (try to obtain that for your animals) and dead elephant parts, and wild Aldabra tortoises eating...other Aldabra tortoises that had died! Hermann's tortoises have been found in the wild eating small dead animals too. Should I then conclude that these species require animal protein in their captive diet?
For me the key is common sense. Separating the good information from the misinformation. What is an acceptable, reasonable practice and what is overkill?
Fortunately, our animals are tough and can appear to do quite well while under widely varying captive practices. If it's working for you keep doing it but don't insist that you've unlocked the secret door to successful tortoise keeping.
Great observations @cdmay
and this part is 100% on point
"For me the key is common sense. Separating the good information from the misinformation. What is an acceptable, reasonable practice and what is overkill?
Fortunately, our animals are tough and can appear to do quite well while under widely varying captive practices. If it's working for you keep doing it but don't insist that you've unlocked the secret door to successful tortoise keeping".
and this part is 100% on point
"For me the key is common sense. Separating the good information from the misinformation. What is an acceptable, reasonable practice and what is overkill?
Fortunately, our animals are tough and can appear to do quite well while under widely varying captive practices. If it's working for you keep doing it but don't insist that you've unlocked the secret door to successful tortoise keeping".
i am of the opinion you can paint all turtles and tortoises with a broad brush when it comes to sunlight . for animals kept indoors replicate the sunlight portion of their environment as best you can , and let them use it as they see fit , it's never going to be a bad thing ......... your never gonna do better than a decent job of replicating sunlight anyway .......... sunlight and reptiles , i'd think it's a no brainer how important it is to their long term well being , and it goes well beyond just d3 synthesis ...........
Wonderful! Thanks for sharing.I called him Butterscotch -
After 1 1/2 months -
2 years 2 months -
3 1/2 years -
5 years old -
This is insightful, especially in the context of your 4+ decades caring for redfoots. Well stated.
It's common among many vegetarian species to opportunistically consume animal proteins. Based on field observations (worked with Mojave desert tortoises for some time) and what I've read, I don't think turtles and tortoises are an exception.
saginawhxc
Well-Known Member
You aren't the only one. I consider myself as fairly bright person, but once we start diving into the science behind some of this stuff I start to feel pretty lost.
It's okay though, I am happy to sit back and read the debate of those who understand it so much better than I do.
Overall this is a fantastic thread and I've really enjoyed it thoroughly.
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