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So What's Up With Aldabra Tortoises?

Discussion in 'United States' started by Coelacanth18, 20 Dec 2016.

  1. Coelacanth18

    Coelacanth18 Well-Known Member

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    So Aldabra tortoises exist in many zoos across the US. They are listed as Vulnerable by the IUCN and there are a very large number of them in Europe as well. However, in looking over the Chelonian TAG RCPs from both 2010 and 2016, there is no mention of Aldabra tortoises in captivity. In both RCPs, they only show up in the total list of chelonian species and nowhere else. I cannot find any information about an AZA program for this species and they are not mentioned in any other documents made by the Chelonian TAG. I found some articles about how the Tulsa Zoo is perhaps the only zoo that has bred them more than once. Here are two articles about that:

    Aldabra Tortoises Hatch at the Tulsa Zoo | Tulsa Zoo

    Tulsa Zoo winning race in Aldabra tortoise breeding programs

    So what exactly is the deal with Aldabra tortoises here? Is there a breeding program or not? Who is coordinating it? Where did all of the tortoises in North America come from?
     
  2. Carl Jones

    Carl Jones Well-Known Member

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    Aldabra Tortoises are bred on Mauritius and Rodrigues (Indian Ocean) in their hundreds and some of these are exported internationally.
     
  3. jayjds2

    jayjds2 Well-Known Member

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    Very interesting questions.

    According to the National Zoo's website, there is a rare subspecies among the population and individuals are being DNA tested.

    Under the Physical Description category:
    https://nationalzoo.si.edu/animals/aldabra-tortoise

    That could potentially cause a halt in any breeding programs.

    As for origins: it's probably safe to assume that a decent amount are wild caught. I remember a post from the National Zoo's Facebook page that mentioned at least one of their individuals was, many years ago.
     
  4. Kifaru Bwana

    Kifaru Bwana Well-Known Member

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    There have been suggestions that Aldabrans in captivity might actually be 3 species. However, when the genetics were done in the US - the same lab that did do all the Galapagos giants genetics work and continues to do so - it was found that they could not find any differences between "true" Aldabrans and other Seychelles tortoises. For now, it may have to be discounted.

    As Carl Jones will acknowledge, the giant tortoises are an important niche in the Indian Ocean island ecosystems and both Aldabrans and some Madagascan tortoises - the radiated tortoise - have been introduced to some Indian Ocean islands to re-establish that lost niche species and provide the ecosystem with an important germination / pollinator agent for various native and often endangered / threatened types of flora.

    I am not sure on the current workings of the AZA on Seychelles or Aldabran tortoises, but the European population is now working more towards making provisions to at least enable some breeding to occur in the near future.

    BTW: The work of the Tulsa Zoo in breeding Aldabrans is something quite out of the ordinary in US / AZA zoos for sure.
     
  5. Carl Jones

    Carl Jones Well-Known Member

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    Aldabra Giant Tortoises show no currently recognised sub-species. The claim that there may be additional taxa, and that some of the extinct Seychelles Tortoises may still be present is not supported by DNA studies. There is considerable variation within the population and some of these these may be morpho-types.

    Aldabra Tortoises have been introduced to the islands of Ile aux Aigrettes and Round Island off Mauritius where they are breeding, and in part are fullfilling the role of the extinct Mauritian species.