Posted by:
tglazie
at Mon Nov 19 10:45:00 2007 [ Report Abuse ] [ Email Message ] [ Show All Posts by tglazie ]
Redfoots are an incredibly diverse group of tortoises, and the delineation between "Cherryhead" and "ordinary" redfooted tortoises is not immediately clear from a scientific standpoint (taxonomists still generally refer to the species as Geochelone carbonaria, although some have disputed the genus categorization as being either Geochelone or Chelnoidis; Geochelone, as you may know, is being disputed essentially world wide in favor of more specific regional names, such as in the way of the Geochelone radiata being changed to Asterocheles Radiata). Now, consider the vastness of South America, and consider that Redfooted tortoises roam over seventy percent of the continent, from Columbia east to Brazil, Brazil South to Argentina, including much of the Peruvian foothills as well as many islands in the carribean (possibly introduced, but we have no records of this, as they would've been introduced during pre-Columbian times). These areas differ quite wildly in their environmental conditions, and this is why we generally see so much variation of redfoots. Now, it is generally true that cherryheads from Argentina and southern Brazil tend to be smaller on the average than other groups of redfoots, especially the "Amazonian giants" that typically populate the northern stretches of the Amazon Basin. However, I've noted that specimins from Venezuela, Surinam, and Columbia (animals most frequently encountered today) are generally the same size, if not slightly larger than cherryheads. I've seen some Argentinian cherryheads as large as nine inches, which is a typical size for most redfoots. Every now and then, one gets the opportunity to see an Amazonian giant, and these can grow up to sixteen or seventeen inches, some possibly larger.
Undoubtedly, integrades do occur naturally. One of mine appears to be such an animal, because it maintains the orange head and scaling features of an "ordinary" redfoot, but has some of the "leopard skin" coloration on its plastron. Keep in mind this is merely speculation, as I purchased him as a wild caught.
Clearly, more study is required. These animals range over several thousand square miles, and it is hard to imagine that they are all members of the same species. Kinixys belliana was once thought to comprise a single species, but those who classified it didn't take into account the enormous color and size variations between the populations. The same is said of Testudo graeca, which initially comprised all of the Mediterranean tortoises from Spain to Morocco to Tunisia to Egypt to Syria then Turkey and Eastern Greece, despite numerous climate differences, color, size and morphological variations. And don't even get me started on Geochelone pardalis and Testudo horsfieldi. So too, I think, Geochelone carbonaria will see a taxonomic adjustment in the near future.
I think the thing to keep in mind here is that variation is complicated. It is enough to make the prospective breeder want to pull his hair out. But the long and short of it is that cherryheads are generally more diminutive in size.
T.G.
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