I thought that this might interest some. This is the blog that announced the importation of 136 ethiopian leopards to Spain 5 years ago'
http://squamatareptiles.blogspot.com/
http://squamatareptiles.blogspot.com/
Ethiopian
- Thread starter yagyujubei
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We used to have a member named Squamata. Wonder if its the same guy. Not very much activity since 2007 for it being a blog.
The TFO Squamata changed his user name to John. He is in New Jersey.
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There is a paper by Hailey and Lambert 2002 "Comparative growth patterns in Afrotropical giant tortoises (Reptilia Testudinidae)" in Tropical Zoology 15: 121-139, 2002 that explains to some extent why these and sulcatas get so big in this part of their range.
In short, they are big because they have a longer annual growing season based on food availability and climate. They measured annual growth of the annuli on scutes. No evidence suggests that they are genetically different, or a separate subspecies. It is a phenotype character of the populations in that part of Africa for leopards and sulcatas.
Will
In short, they are big because they have a longer annual growing season based on food availability and climate. They measured annual growth of the annuli on scutes. No evidence suggests that they are genetically different, or a separate subspecies. It is a phenotype character of the populations in that part of Africa for leopards and sulcatas.
Will
Wow! And I was just reading aLeopard tortoise book today that suggested a third sub species. Cool! 
yagyujubei said:
Did you see the tortoise forum that was based in Spain? Someone posted about it here a few months back, and I know were not allowed to talk about other forums", but a lot of people had Somolian leopards. There were some cool pics.
Will:
I didn't read it...not enough time right now, but how does it explain that those tortoises still grow big when removed from that environment and kept, say, here in the U.S. Does it have to do with a change in their genes?
I didn't read it...not enough time right now, but how does it explain that those tortoises still grow big when removed from that environment and kept, say, here in the U.S. Does it have to do with a change in their genes?
Seems to me I remember someone telling us the last time this was brought up that most of those tortoises died.
emysemys said:
What do you mean? If I get your meaning, my response is that their genes do not change from being moved from one place to another over a short period, as if I transported some leopards from there to here. That is not how genes work.
One could select for more size by breeding largest to largest and weeding out -say- the bottom 90% or so of animals as it relates to size or rate of growth. That would then, over time, increase the frequency of whatever genes may be contributing to enhanced size. This would take a very, very, very long time.
Genetic giants could pop up randomly as a matter of spontaneous mutation, but that is of low probability and is not able to be planned for. You would then need to reproduce the animals carrying any exceptional genes for growth.
A big issue preventing more interesting selective/directed breeding efforts is the rate-limiting effect of generation time, with tortoise maturation being relatively slow in comparison to things like geckos or ball pythons. Random events are more likely to be discovered with larger numbers of animals. This can be seen in large RES farming operations, where new traits can be found from time to time. It would take an enormous number of tortoises to approximate that sort of production capacity.
Just read the paper. It was interesting, especially involving the two major growth phases. It admits some of its limitations and highlights some of the strengths in data collection. I felt the sampling was low, but I liked it for what it was. The higher growth as a phenotypical result of greater or longer-lasting resource availability was a suggested probability and not a stated fact. Another aspect was simply adult survival. We would need larger sample sizes for greater statistical confidence and help to avoid some of the modeling problems encountered, as exclusions had to be made from already limited sample sets. I, too, wish they could have swapped locale-originating groups with others to observe their growth, but time is always a big PITA standing in the way of such an undertaking. I found it questionable that they did not find a great degree of sexual dimorphism in the form of length for the sulcatas.
In short, some animals grow big because they grow quickly (with a likely strong genetic component), while other types may grow larger with adequate time and/or nutritional resources (environmental beyond a certain base genetic point). The authors hypothesize that the larger Somali leopard tortoises manage to become so mainly thanks to a more facilitating environment and a longer adult survival time.
Thanks again for the paper, Will.
In short, some animals grow big because they grow quickly (with a likely strong genetic component), while other types may grow larger with adequate time and/or nutritional resources (environmental beyond a certain base genetic point). The authors hypothesize that the larger Somali leopard tortoises manage to become so mainly thanks to a more facilitating environment and a longer adult survival time.
Thanks again for the paper, Will.
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