subadult?

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Re: subadult?

Postby Mario Schweiger » Mon May 14, 2012 12:57 pm

Jeroen Speybroeck wrote:Back on track!

Thanks, Mario, for your insights. However, I often get the feeling that the available data (e.g. as summarised by the Handbuch) on growth and population dynamics of European snakes is not really based on decent sample sizes etc. What do you think?

If population A has e.g. more food available than population B, what will happen =>
(1) maturity will be delayed until the same size is reached as in any population or
(2) maturity will be reached at smaller size in B vs. A ?


a) it seems, there are much to less data in the "Handbook".

b) I will give an example of my loves: Vipera ammodytes:
Although I have no real idea, it seems all (or most at least) mainland populations will get maturity at nearly the same size: approx 50 to 60 cm.
On the other hand, many of Aegaean populations are breeding with less than 30 cms (I´ve seen copulating on Naxos with 26 to 28 cms), and dont grow even much larger. I´m nearly sure, it depends on "not really adequat food", mainly only lizards. But when you breed these pigmies in a terrarium and feed the offspring, starting with mice pinkies, following with mice of "fitting size", they grow to the same size as mainland vipers - with the same speed!
Maybe the same with quatuorlineata from the Aegaean islands?

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Re: subadult?

Postby Jeroen Speybroeck » Mon May 14, 2012 1:19 pm

Interesting to say the least, thanks!

Mario Schweiger wrote:it seems, there are much to less data in the "Handbook".

Not sure I understand... You mean there's a great variability in the book concerning amount of info according to which species and aspect etc.?

Mario Schweiger wrote:Maybe the same with quatuorlineata from the Aegaean islands?

I would expect that in a rather small sized species like ammodytes, differences in size at maturity in different regions, places, ... (if any exist!) would be too small to be obvious during 'regular' observations. I mean that maybe these diffences exist but are less pronounced. Also, you could expect a mix of large-scale regional/geographical trends + patchy variability at a smaller geographical scale due to habitat quality, with varying importance of both.
And what about body mass? Surely strongly correlated to size, yet still...

So, Mario, you would expect that there is variation in the timing of the pattern transition, rather than in the size at maturity in quatuorlineata? In other words, some can clearly be mature without having the adult pattern yet?
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Re: subadult?

Postby Mario Schweiger » Mon May 14, 2012 1:30 pm

So, Mario, you would expect that there is variation in the timing of the pattern transition, rather than in the size at maturity in quatuorlineata? In other words, some can clearly be mature without having the adult pattern yet?


Yes for sure!
See my both males, I have posted pictures.
I´m sure both are mature, although the larger one still has blotches (and stripes).
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