Tortoise Mythbusters Part 2!

[Madkins007]

I was not expecting this thread to be so interested. Great thread. I amn amazed at how smart/knowledgable some of you are.

Ha! I just don't have many other hobbies and really like to read about stuff and share what I learn. If the thread was something like the upcoming Superbowl, I could not contribute squat. I honestly do not know who is even playing.

But since I like research, I looked it up to see that NFL and AFL are involved somehow. Further research shows that the AFL is the Australian Football League and their Grand Finale is October 1, 2011, so I am not sure why all the hype this early. I am also a bit unsure why they would play the National Forensics League here in the US? Debate and Aussie football go hand in hand, certainly, but this seems to be taking it too far.

Oddly, I find no info on the Superbowl site anything about Australia or Forensics, so apparently they are hugely confused about it all too. Heck, the ball they call a 'football' doesn't even look like a BALL, much less the football the Australians use.

Further, all of the players in the Superbowl site are wearing some sort of helmet-like headgear that none of the people in the AFL or NFL's sites show. I can sort of see the need for headgear playing Aussie 'football', but why would debaters need it?

 

[Balboa]

ROFLMAO

 

[Redfoot NERD]

I haven't done near the level of research that either Mark or Carl have, but I have gotten the distinct impression that even when living in the "savannah" type biomes, redfoots prefer what's called gallery forests. If you have ever driven through arid parts of the midwest you've probably seen them before. These are the narrow forests that grow along river banks, but get more than a stones throw from the river and it goes to grassland.

It makes me think the term "near-forest" is perfect for redfoots. Its like they ideally want to be at most a days walk from either forest or field at any given time.

I agree with the "close-to" idea Balboa.. and they proby don't get much more than a few hours away - why would they?.. nothing to speak of to eat, drink or hide in!

Since '05 I've claimed they were "near-forest".. on my caresheet - so you know I believe it to be a perfect term.

The main difference is Mark researches and Carl has experienced many of these characteristics [ as well as a few others ] first hand or have friends/acquaintances that live where these creatures live.

[ I'm looking for a related email from a keeper in Rio De ]

NERD

 

[Candy]

Ha! I just don't have many other hobbies and really like to read about stuff and share what I learn. If the thread was something like the upcoming Superbowl, I could not contribute squat. I honestly do not know who is even playing.




Are you kidding me Madkins? GREENBAY ALL THE WAY!

 

[Madkins007]

I haven't done near the level of research that either Mark or Carl have, but I have gotten the distinct impression that even when living in the "savannah" type biomes, redfoots prefer what's called gallery forests. If you have ever driven through arid parts of the midwest you've probably seen them before. These are the narrow forests that grow along river banks, but get more than a stones throw from the river and it goes to grassland.

It makes me think the term "near-forest" is perfect for redfoots. Its like they ideally want to be at most a days walk from either forest or field at any given time.

I agree with the "close-to" idea Balboa.. and they proby don't get much more than a few hours away - why would they?.. nothing to speak of to eat, drink or hide in!

Since '05 I've claimed they were "near-forest".. on my caresheet - so you know I believe it to be a perfect term.

The main difference is Mark researches and Carl has experienced many of these characteristics [ as well as a few others ] first hand or have friends/acquaintances that live where these creatures live.

[ I'm looking for a related email from a keeper in Rio De ]

NERD

Apparently, the word 'forest' is causing confusion. A forest or 'forest edge' animal needs the trees. They provide food, shelter, ways to hunt or hide, etc. They regulate the climate, lighting, etc. Yellow-foot Tortoises are a true forest animal. They eat more fruit, are more light and climate sensitive, and do not even dig nests or use burrows since they would just flood.

Red-foots do not need trees in the same way. Some of their fruit still comes from trees but as much or more comes from cacti, shrubs, etc. They don't need trees to block the light, provide shelter, hunt from, hide from predators in, etc. Trees are around, but relatively unimportant in most Red-foot habitat.

Red-foots are also almost always found near water, but we do not call them riparian or riverine animals because they are not using the riverside habitat in a special way. However, the presence of water is MUCH more important to them and their habitat selection than the trees are. The trees are there for the same reason- reliable access to water.

Since they don't need forests, they are not a forest or forest edge animal.

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Heck, NERD, you don't need to wait for an email, just look at the tortoise farm sites http://www.geochelone.com.br/usa/index.cfm and http://www.carbonaria.com/index.html. They are by people who live in the Cherry-head tortoise zone, and have raised thousands of Red-foots in or near their native habitat. They are actually between Rio de Janerio and the Amazon Rainforest, so should be more 'foresty' than Rio, right?

The first site (Santa Rita) says "Bahia's countryside is very dry. When the drought time comes ,the animals and plants die because of the hot sun and the lack of rain ; the animals try hard to survive and find some food and water , but the weakest ones always perish."

The second site (Santa Cruz) says "Geographically it is inside of the semi-arid zone of the Bahia state where the average rainfall is 600mm yearly.

Nothing to eat, drink, or hide in? How do grassland tortoises around the world live in savannah habitats then?

.......................................................

In an earlier post, NERD said
"Does maintaining [ like a few of us have ] redfoot tortoises for at least the first 'phase' of their life count for anything? - that would be the first 10+ years from hatchling to a mature adult demonstrating the ability to produce off-spring.

Would that experience indicate where they prefer to abide 'most' of the time?

A few of us ( Carl in particular ) know those that have maintained a multitude of redfoot tortoises for decades - but it's virtually impossible to get them to talk......... they being a much better source than someone who has spent a much shorter time [ in comparison ] traveling around in South America observing smaller areas and numbers.... and then writing about them."

I was going to ignore this, but as long as I am responding to another NERD post, I may as well hit this as well.

1. I consider NERD knowledgeable in raising Red-foots in Tennessee. He has 5-10 years of experience and has seen about 200 torts. He has certainly bred them, but seems to have low reproductive success so far, which he even comments about on his site.

2. The people I trust for references and advice have bred more animals for a lot longer. I have not asked for permission to use any of their names here.

3. Besides the experienced breeders I have listened to, I have also read the books, articles, reports, abstracts, etc. of dozens of researchers working over a hundred years and documenting thousands of tortoises.

4. Some of the researchers actually LIVE IN THE AREA where Red-foots are found. NERD mentions a contact in Rio de Janerio- a place on the very edge of Red-foot territory. Many other people have lived in the heart of the territory and have added their own writings to the collection.

5. Sources? Check out http://www.tortoiselibrary.com/bibliography.html for articles and books by De Sousa, Fidenci, Freiberg, Iverson, Legler, Merchan, Ojasti, Pritchard, Trebbau, and Vargas-Ramirez- and those are just the ones I listed there. There is much, much more online, although much of it is in Spanish and is harder to search.


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None of this changes the fact that the Red-foot Tortoise needs warm, humid habitat most of the time.

 

[Candy]

What Mark you can write all that to Terry, but you can't even acknowledge that I told you who was going to the Superbowl? And by the way the second link didn't work for me could you post it again? By the way.....Way to "Man-up" on that post.

 

[DoctorCosmonaut]

I really want somebody to post pictures of these habitats... places where they found real, wild RFs... That'd be neat.

 

[Redfoot NERD]

Maybe we can relate this topic to a "Dog HUNT" Mark - hunting here and there to determine where would be the "best" environment for a redfoot tortoise to live? We can always talk about the exceptions and extremes.. even tho' they have been known to live there also.

There are a very few [ of us ] actual long-term keepers/breeders that even frequent this forum. And more and more fewer are saying less. Each and every one has told me personally that whenever the environment becomes a 'challenge' and/or their care is compromised in even the slightest way.. temps, humidity, diet, etc., etc. their redfoots seem to be 'unhappy'? and not want to or actually do not produce with the consistency they once had in the past.. meaning numbers and colors.

When I asked or commented if ( our ) personal experiences counted for anything it was only that.. a simple question and/or comment - not to cause a Dog FIGHT. It almost seems Mark that that is what you have made this topic. And for that reason I'm really sorry this has played out like this.

Hopefully this is not edited in any way.

And hopefully not one thinks that they can keep redfoot tortoises in a sparse hot and dry environment. The adverse extremes found in any of these links and statements are just that.. extremes.

And yes the least of Marks above is true..
"None of this changes the fact that the Red-foot Tortoise needs warm, humid habitat most of the time." - maybe this should have been emphasized?

NERD

 

[Madkins007]

Candy- My dad was a diehard Packers fan, so even though I honestly don't follow football, I thought it was funny that you chose them as well, and apparently they are in!

The second link is the the Santa Cruz Tortoise Farm- http://www.carbonaria.com/prod.htm . Hopefully, that will work.

Jordan- the book 'South American Tortoises' by the Vinke's shows a lot of habitats. There are also some on-line articles the Vinke's have written that you can find in the Bibliography in the Tortoise Library- http://www.tortoiselibrary.com/bibliography.html that show some illustrations. The two tortoise farms mentioned above also show some.

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Sorry, NERD- I wasn't the one looking for a fight. You posted that first bit challenging me, trying to bait me by claiming that for some unknown reason, the experience of a guy over a few years with a handful of tortoises is somehow superior to research, documentation, the experiences of other people, etc. I ignored it. Then you posted some more along the same lines and I replied.

You were looking for a fight. You may claim you are all pure and innocent, but you started it and when no one rose to your bait, you tried again. You are still mistaken in your opinion that Red-foots are primarily a rainforest species, so you try to veer the fight a bit to the side- trying to me look like the bully, suggesting that someone would edit your post (as if!), etc. You even mentioned the warm and humid bit again as if that was the main point and I was telling people to raise them cold and dry or something. What a crock.

If you want to discuss their primary habitat choices, fine- show me something that looks like proof or research. Whip out your copy of Deb Moscovits' dissertation or something. Show me emails from people in the midst of true Red-foot habitat that have actually explored other areas for population comparisons, something. You mention Rio de? There are those who suggest that the Red-foots in Rio de Janerio are a colony started by released pets since Rio is so far from other Red-foot territories. You DID know that Rio is far, far from the Amazon rainforest, right?

Heck, maybe you can explain to us why you call this a 'forest edge' species when the local name of the species is Savannah Tortoise. Stick to the real topic and I will be happy to keep discussing it with you.

 

[Candy]

Thanks for posting the second link and yes it did work.

 

[terryo]

I really want somebody to post pictures of these habitats... places where they found real, wild RFs... That'd be neat.

No pictures Jordan, but the next best thing. Very interesting article from Andy Highfield.

http://www.tortoisetrust.org/articles/pyramiding.html

 

[Madkins007]

TerryO- that is a GREAT article! I strongly recommend it and many others in at http://www.tortoisetrust.org . As people read it, however, remember that it applies to Mediterranean species and not necessarily to Red-foots in regards to the low humidities found.

The South American Chaco Tortoise comes from similar habitats in South America, especially in the Gran Chaco region of southeast Brazil, Paraguay and Bolivia, but Red-foots, even from that same area, are usually found in greener, damper, more humid microclimates.

 

[terryo]

TerryO- that is a GREAT article! I strongly recommend it and many others in at http://www.tortoisetrust.org . As people read it, however, remember that it applies to Mediterranean species and not necessarily to Red-foots in regards to the low humidities found.

The South American Chaco Tortoise comes from similar habitats in South America, especially in the Gran Chaco region of southeast Brazil, Paraguay and Bolivia, but Red-foots, even from that same area, are usually found in greener, damper, more humid microclimates.

Mark I just saw the map in your library. I love it! You never stop amazing me with all your research. I want a BOOK!!

 

[tortoises101]

"It is hard to find records of large numbers of Red-foots in the same locations as Yellow-foots. There are some places, like the island of Maraca (where Deb Moscovitz did her famous dissertation), where you can find both, but that is considered a bit of an anomaly by a lot of field researchers."

I believe that it's because redfoots and yellowfoots may be competitors with each other (space, diet, food, etc). That's probably why in some places you can find redfoots in rainforests with no yellowfoots and some places you can find yellowfoots in tropical savannas with no redfoots.

 

[Madkins007]

"It is hard to find records of large numbers of Red-foots in the same locations as Yellow-foots. There are some places, like the island of Maraca (where Deb Moscovitz did her famous dissertation), where you can find both, but that is considered a bit of an anomaly by a lot of field researchers."

I believe that it's because redfoots and yellowfoots may be competitors with each other (space, diet, food, etc). That's probably why in some places you can find redfoots in rainforests with no yellowfoots and some places you can find yellowfoots in tropical savannas with no redfoots.

Do you have any research to back that thought up?

For my side of the discussion, there are museum specimens of Red- and Yellow-foots that have been collected for over a hundred years with locality info recorded, many reports of field studies form people who live there, and more that support the idea that Red-foots are not common in the rain forest and Yellow-foots are almost never found outside it. And of course there are the other documents I mention in the OP.

There also has to be a reason the two species split some 4 million years ago- and the geological history of the area seems to support the idea that the splits occurred as the conditions of the rainforest shifted, and the range and timing also suggest that the Yellow-foot colonized the rain forest, and the Red-foot did the rest of the South American tropics.

 

[tortoises101]

"It is hard to find records of large numbers of Red-foots in the same locations as Yellow-foots. There are some places, like the island of Maraca (where Deb Moscovitz did her famous dissertation), where you can find both, but that is considered a bit of an anomaly by a lot of field researchers."

I believe that it's because redfoots and yellowfoots may be competitors with each other (space, diet, food, etc). That's probably why in some places you can find redfoots in rainforests with no yellowfoots and some places you can find yellowfoots in tropical savannas with no redfoots.

Do you have any research to back that thought up?

For my side of the discussion, there are museum specimens of Red- and Yellow-foots that have been collected for over a hundred years with locality info recorded, many reports of field studies form people who live there, and more that support the idea that Red-foots are not common in the rain forest and Yellow-foots are almost never found outside it. And of course there are the other documents I mention in the OP.

There also has to be a reason the two species split some 4 million years ago- and the geological history of the area seems to support the idea that the splits occurred as the conditions of the rainforest shifted, and the range and timing also suggest that the Yellow-foot colonized the rain forest, and the Red-foot did the rest of the South American tropics.

http://nlbif.eti.uva.nl/bis/turtles.php?selected=beschrijving&menuentry=soorten&id=380
On the habitat section.

 

[Madkins007]

Tony- isn't that a great site?

From the site:
"Habitat
Where it is sympatric with Geochelone denticulata, G. carbonaria is more prevalent in moist savannahs (which are seldom entered by denticulata), but where denticulata does not occur, carbonaria seems to be a humid forest dweller. Perhaps there is competitive exclusion by denticulata."

Sympatric means the ranges overlap. I got my wrists slapped by an experienced keeper when I mentioned that sympatric meant they shared habitat. Trout and elk are sympatric, but do not share habitat, which would be 'syntopic' if I recall the term correctly.

As the article mentions, Red-foots (G. carbonaria for those who need a scorecard) are mostly found in wet savannah (which is not quite true. Wet savannah technically is more of a marsh like habitat much of the year. They are found in the wet parts of dry savannah according to most researchers)

The idea about competitive exclusion is the idea that back a few million years ago, when G. carbonaria split from G. denticulata (Yellow-foots in case some readers are getting lost with the scientific names), the Yellow-foots were the masters of the rain forest habitat and generally bigger, so the Red-foots exploited other habitats.

Another version of this possibility is that the groups of tortoises were separated by climatic or geographical changes- rainforest breaking up into segments separated by rivers or other barriers.

I made up a map at http://www.tortoiselibrary.com/rangemap.html that combines info from Pritchard's "Turtles of Venezuela", Iverson's turtle maps (http://emys.geo.orst.edu/cgi-bin/emysmap?tn=137&cf=ijklmno), and info from others. On it, the Yellow-foot range is basically the same as the extent of the Amazon Basin rain forests. Most Red-foot range is to the north or south of the Basin, and records IN the basin are spotty, other than a few areas with forest openings, etc.

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OK, so why is this Myth even an issue? Because of the effects it has on cares.

We have heard from people who believe this to be primarily a deep forest animal that Red-foots are light-shy, but most keepers find that this is not true. Sure, the babies are, but all baby tortoises are shy. (And, of course, you can easily offer too much of the wrong kinds of lights.)

We hear that that Red-foots don't need UVB because they would not get it in the deep forest. This is not true on a few levels- UVB does penetrate more than visible light does and hits the forest floor, and Red-foots are not deep forest animals anyway. Wild fungi are also rich in vitamin D (unlike store-bought mushrooms) and a popular food of forest species.

We hear that Red-foots don't bask. Yet Red-foots are well-documented basking in the wild and bask in the sun or under lamps for lots of keepers.

We are told by some that they don't need a temperature gradient, yet even in the deepest rainforest, temps vary by up to 20 or more degrees naturally between microclimates. Red-foot habitat in South America experiences a wide range of temperatures and climatic conditions. Red-foots in captivity are often seen using temperature gradients to thermoregulate.

There are also dietary issues related to this, like the proportions of fruit or meat we offer- almost always too much of foods that are too rich in protein, carbohydrates, fats, and so on. But we do it anyway because 'forest tortoises eat a lot of fruit and meat' without putting that information in the proper context.

As I've said a few times already- warm and humid is still correct. Even the grassiest area Red-foots come from are more humid than the typical grasslands around the world.

 

[Balboa]

The red-foot, yellow-foot conundrum is a fascinating one isn't it? Mark and I have already debated back and forth about it many times.

I shared this paper a while back with Mark
http://www.evoamazon.net/Legal_papers/Farias 2007.pdf

Their findings (at least in the sympatric area they studied) showed gene flow between denticulata and carbonaria, as well as much greater gene diversity in Denticulata versus Carbonaria. There were also indicators that Carbonaria was in "rapid expansion".

I forget where, though I'm sure if I tried hard enough I could dig it up, I read that some of the only fossil remains yet to date found for the genus were closer to Denticulata than Carbonaria.

All this leads me to believe that Denticulata is essentially the proto-species for Carbonaria, an off-shoot of chance, more specialized for life further outside of the "rain-forest".

Another element to consider is that the rainforest looked very different from what it does today just 500 years ago. It was host to a fairly advanced human civilization that has now vanished (researchers hypothesize that disease spread by the conquistadors eradicted it) and the jungle has reclaimed its land.

This civilization likely had a dramatic impact on the distribution of both Denticulata and Carbonaria.

To bring this all back to the point, it becomes a very complex issue to understand the proper place of both species in south america. How things are now is not how they were for the majority of the last few thousand years.

 

[Madkins007]

(snip)

This civilization likely had a dramatic impact on the distribution of both Denticulata and Carbonaria.

To bring this all back to the point, it becomes a very complex issue to understand the proper place of both species in south america. How things are now is not how they were for the majority of the last few thousand years.

And even that history pales in comparison to the estimated 4 million years since the Red-foot is thought to have split from the Yellow-foot in!

 

[methos75]

I have to point out some of my own recent experiences with Redfoots, and their lighting and UVB needs. I like many others looked at where the many care sheets stated they avoided bright lights, and placed them in set-ups with dim lights. Also we fore go the use of UVB lights, since it was stated diet was more important. I kept my set-up at 95 degrees on one side and 75-80 degree on the other, my Redfoots were active in the morning and late evening and that was it, other than that they slept in their hide. Last week I changed up their set-up and placed a much brighter 100 Watt light over their basking area, and placed a flat rock under it, but temps stayed the same basically. I increased the lighting also by adding a 10.0 Reptisun Bulb, so that there was more light as well as UVB getting to them. The result of this is two vastly more active Redfoots who stay out all day now exploring and basking for hours a day, and who eat much better. IMO its obvious that some of the general info we hear could be very wrong about these things.