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White tigers, yes or no ?

Discussion in 'General Zoo Discussion' started by vogelcommando, 20 Feb 2014.

  1. vogelcommando

    vogelcommando Well-Known Member 10+ year member

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  2. Hix

    Hix Wildlife Enthusiast and Lover of Islands 15+ year member Premium Member

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    This topic has been discussed before:

    http://www.zoochat.com/2/white-tigers-100420/
    http://www.zoochat.com/2/argument-white-tiger-extinction-301399/

    My view, for what it's worth -

    I agree with pretty much everything that was said in the paper, but....

    The white gene was derived from a wild animal. It is a mutation that has occurred a few times in the past and is a part of the animals genetic make-up.

    The white tigers in the world's zoos will never be put back into the wild, and most of the normal tigers won't be either, because they have genes from more than one subspecies.

    However, if a purebred Bengal carried the gene (and sometimes produced white offspring) that is not a reason to not breed from that animal. I'm not saying deliberately produce whites, I'm saying don't stop breeding because you are afraid of the gene being passed on.

    In fact, if you were re-introducing Bengals into the wild I think it would be optimal to have one or two that carry the gene to be re-introduced into the wild population, especially when re-stocking areas where tigers are no longer present. Yes, white cubs may periodically appear, and they may die as cubs, as Landers suggests. But white tigers have been seen as adults in the wild in the past. Nevertheless, the gene is part of the genome.

    My concern is that people may want to deliberately exclude the gene from a wild re-introduced population, which would be wrong. Because genetic diversity (including mutant genes) is what adaptation and evolution is all about.

    :p

    Hix
     
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  3. Arizona Docent

    Arizona Docent Well-Known Member 15+ year member

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    It is interesting that AZA facilities seem to be anti white tiger, yet they seem to have no problems exhibiting leucistic and euthristic reptiles, which are seen at almost every AZA zoo I have been to.
     
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  4. dean

    dean Well-Known Member 10+ year member

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    I can't see the attraction in white tigers and less so in White reptiles, my first ever exotic animal was an American tree frog Possibly Hyla regailla, which was a very light green at it's darkest and cream the rest of the time. The pet shop owner said unbelievably" feed it on lettuce leaves and things like that and it will turn more green" I had him for years and he got paler with age. He taught me a lot about keeping tree frogs in captivity.
     
  5. elefante

    elefante Well-Known Member 10+ year member

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    I like to see unusually colored animals in zoos, but I do agree that it is better to keep animals that have conservation value. As much as I like black panthers, I do think it is more important to keep endangered subspecies like Amur leopards than generic panthers. That being said, I can't imagine there wouldn't be some melanistic jaguars from time to time.
     
  6. TheMightyOrca

    TheMightyOrca Well-Known Member 10+ year member

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    Apparently the issue is that most, if not all white tigers are terribly inbred. As far as I'm aware, leucistic animals generally don't have this problem, but feel free to correct me if I'm wrong. It's more a matter of genetic health than appearance.

    That said, I think breeding white tigers should be done on an animal-by-animal basis. If there's a white, pure Bengal tiger that is healthy, would breeding it really be that bad?
     
  7. TheMightyOrca

    TheMightyOrca Well-Known Member 10+ year member

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    Apparently melanism is a dominant gene, so they generally don't need to be inbred, and apparently they don't have problems surviving in the wild.
     
  8. dean

    dean Well-Known Member 10+ year member

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    There could be an advantage in being mechanistic in nature, as black can blend in very well in dark forested areas ,they tend to look like shadows and could go unnoticed. Where as white or very pale animals stand out, -unless you are a bear in the arctic of course- hence they are easy prey for a larger hunter, or have difficulty catching prey themselves.
     
  9. Hix

    Hix Wildlife Enthusiast and Lover of Islands 15+ year member Premium Member

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    Dominant? That's the first I've heard of it.

    :p

    Hix
     
  10. azcheetah2

    azcheetah2 Well-Known Member

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    I agree. If the cat is a naturally occurring white and not as a result of in-breeding then they shouldn't not allow it to breed just because it might pass on the white gene. But I don't know if there's a way to guarantee that white cat happened naturally unless it was wild-caught and then you open a whole new kettle of worms.
     
  11. TheMightyOrca

    TheMightyOrca Well-Known Member 10+ year member

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    Zoos today keep track of animal lineages. Add in some genetic testing to confirm and it wouldn't be so difficult to prove.

    Though another concern is; is it true all white tigers are cross-eyed because the white gene causes it, rather than being the result of inbreeding? If that's the case, it's a a health problem and maybe they shouldn't be bred. I dunno.
     
  12. ralph

    ralph Well-Known Member 10+ year member

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    The melanism gene is dominant in jaguars, but recessive in leopards, servals and other species of wild cats. Which explains why black jaguars are quite common.
     
  13. Arizona Docent

    Arizona Docent Well-Known Member 15+ year member

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    One researcher put forth the dominant jaguar theory a few years ago but I do not think it is correct. I think it is recessive just like leopards and I know a prominent wild cat expert who thinks the same.
     
  14. Hix

    Hix Wildlife Enthusiast and Lover of Islands 15+ year member Premium Member

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    If it was dominant you would expect most jaguars (i.e. >75%) to be black. The studbooks would have proved conclusively if it was dominant.

    :p

    Hix
     
  15. Pertinax

    Pertinax Well-Known Member 15+ year member

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    and a spotted Jaguar in the wild would be an exciting rarity...;)
     
  16. ralph

    ralph Well-Known Member 10+ year member

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    No. It's not as simple as our high school biology lessons make it appear.
    Many sources confirm that, in jaguars, melanism is in fact caused by a dominant gene.

     
  17. Hix

    Hix Wildlife Enthusiast and Lover of Islands 15+ year member Premium Member

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    Can you cite that source, please?

    :p

    Hix
     
  18. ralph

    ralph Well-Known Member 10+ year member

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    I'm actually not sure where I found that, but you should be able to find multiple sources confirming the information stated above by simply doing a websearch. Or, if you or anyone else can point me towards a source that disproves this, feel free to share that with me.
     
  19. Arizona Docent

    Arizona Docent Well-Known Member 15+ year member

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    I am no scientist so maybe I do not understand how the dominant and recessive gene works. Here is how I thought it worked.

    The dominant gene is the one whose characteristic is displayed in a heterozygous individual (who has one of each gene). So if you have one black and one normal (yellow) gene, you will be yellow if that is dominant and black is recessive, but you will be black if that is dominant and yellow is recessive.

    If, therefore, the black gene is dominant in jaguars that would mean all yellow jaguars are homozygous with two yellow genes, since an individual with one of each gene would always be black. So I guess the way to test it is to see if two yellow jaguars that are mated ever produce black offspring? If they do, then the black must be recessive but if not then maybe it is dominant. Anyone know of any instances of two yellows producing a black cub?
     
  20. ralph

    ralph Well-Known Member 10+ year member

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