Races or Types of Red-Footed Tortoises

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Madkins007

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Introduction

Based on physical evidence, location data, and DNA studies, there seem to be 5 distinctive races, groups or types of red-footed tortoise (Chelonoidis carbonaria), and some variation even within the main groups. These groups are not species or subspecies yet, but many researchers think it is just a matter of time before something changes in this group. (There is no evidence that there are races or groups of yellow-footed tortoise (C. denticulata))

The groups are:
- PANAMANIAN (Northeastern)- Panama and west of the Andes in Venezuela
- COLOMBIAN (Northern)- Colombia, south of Venezuela. This was not a group that has been discussed widely as a separate group before. They seem to look a lot like the next group.
- GUYANAN (Northwestern)- The 'Guyanan Climatic Zone' of mid-Venezuela to French Guiana and bits of northern Brazil
- BRAZILIAN (Eastern)- The 'Cherry-heads' and there yellow-headed but otherwise identical kin from the central-to southern part of Eastern Brazil
- GRAN CHACO (Southern)- Paraguay and Bolivia

The names used here are unofficial. The names used in parenthesis are from Vargas-Rameriz, who did the DNA study this is based on. I prefer to not use his terms since we tend to break the groups into two 'supergroups'- the Northern and the Southern, roughly divided by the Amazon River drainage basin.

Characteristics of the Groups

First, we can usually divide the Northerns from the Southerns by the plastron:
Northern- mostly light plastron, some dark patterning in the middle of the plastron.
Southern- mostly dark plastron, some mottling or light patterns in the middle of the scutes

There are other differences that are less visible.
- Adult male Southerns tend to not show the 'wasp waist' of the Northerns. There are also more subtle shell shape differences between both sexes of both groups.
- Southern climates tend to run cooler, and hotter/dryer depending on the season. Cacti are a main food source.
- Southerns seem to be more territorial, and males are more aggressive.
- There seem to be differences between growth rates, reproductive cycles, etc. but these are not as well documented.

Characteristics of the groups:

- Guyanan (E. Venezuela to French Guiana): the 'typical' Red-foot. 30-35cm adult length, black carapace background, constricted waist on adult male, yellow/orange/red colors on limbs.

- Panamanian (Panama, W. Venezuela): Shell background is more coffee/grey, almost no red coloration on limbs.

- Colombian (Colombia): Nearly identical to Panamanian.

- Brazilian (East Brazil): This region seems to be home to 2 variants- the 'red' and the 'yellow'.

----'Reds' are the 'cherry head' variant. These MAY average a bit smaller (22-28cm), but many specimans are a bit larger than average. Reds tend to have very dark necks with bright red or orange colors on it. They tend to show shell mottling more often than others, and seem to have a slightly bulbous red-tip nose (the Rudolph Sign). They rarely show the male wasp-waist, but usually have a distinct hooked scale below the front elbows- almost a 'spur'.

----'Yellows' look like 'reds' in size, etc. but have shell and limb coloration more like the Guyanans.

- Gran Chaco (Paraguay and Bolivia): Big- 35-45cm- tortoises, similar to the 'yellow' Brazilians with less colorful shells and skin.

Helpful Links
- ADKINS, Mark. "Cherry-heads or Brazilians" and "Natural History" The Tortoise Library.com [Disclosure- the Tortoise Library is my site]
- PRITCHARD, Dr. Peter C. H. "The Encyclopedia of Turtles". TFH Press. 1979.
- PRITCHARD, Dr. Peter C. H.; Trebbau, Pedro. "The Turtles of Venezuela". Society for the Study of Amphibians and Reptiles, Contributions to Herpetology No. 2, 1984.
- VARGAS-RAMIREZ, Mario; Maran, Jerome; Fritz, Uwe. "Red- and yellow-footed tortoises, Chelonoidis carbonaria and C. denticulata (Reptilia: Testudines: Testudinidae), in South American savannahs and forests: do their phylogeographies reflect distinct habitats?"
- VINKE, Thomas and Sabine. “The Turtle and Tortoise Fauna of the Central Chaco of Paraguay” Radiata 10:3, 2001.
- VINKE, Thomas and Sabine. "An Unusual Survival Strategy of the Red-Footed Tortoise Geochelone carbonaria in the Chaco Boreal of Paraguay." Radiata 12(3) 2003, “Habitat Observations”.
- VINKE, Thomas and Sabine; Vetter, Holger and Susane. "South American Tortoises, Chelonian Library Vol. 3". Chimera Edition, 2008.

The discussion thread (and original post) for this topic- with pictures!- is: http://www.tortoiseforum.org/Thread-The-Different-Races-of-Redfoot-Tortoise#axzz1mhMvoWah
 
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