Elcho Is. Childreni... Educate me.

[Gruni]

At risk of further flame retribution and over reaction I am going to reopen this topic as a thread of it's own.

After seeing this thread (http://www.aussiepythons.com/forum/sale-snakes-43/adult-elcho-island-childreni-pair-178848/) in the for sale section {copyright to Billy/Bonustokin for his post and pics} it got me to wondering more about these Childreni.

The adults are certainly stunning. I was recently chastised for daring to hold the opinion that the hatchies look like Macs when they are born [and for 'copyright' reasons I shan't post the link to any of the images that made me think so but you may readily Google them for yourself] but in Billies post he shows last years hatchies and they already look more like the adults.

SOOOOOOO... please fill me in on these charming individuals. Are they categorised as Childreni based on DNA or scale count/variation etc? Are they all born spotty? At what age do they loose their pattern? Any other remarkable traits/habits/observations.

I may be wording this a bit tongue in cheek after the uproar of the last thread but I genuinely would like to know more about them as despite looking at several books containing info about Antaresia while looking into buying Skittles none of them mentioned the Elcho Is. 'strain'.

P.S. If I am ever in the Balina area again Billy I'll try to look you up, you seem to have a great little collection happening.

 

[Sdaji]

I didn't see the fun and games you're talking about, but they're quite clearly Children's based on location and appearance. As far as species definitions go, the split between Children's and Stimson's is pretty stupid (they have a continuous distribution with freely exchanged genetics and they gradually merge from one to the other, with no clear line separating them, it's all very arbitrary, and of course there is no obvious genetic distinction with a situation like that).

They don't look anything like Macs. I won't chastise you, it's easy enough to make the mistake if you're inexperienced, but they are quite clearly different. The most immediately obvious difference is the pale lateral stripe (which essentially all Children's and Stimson's have, but Macs don't). There are other subtle differences in pattern, scalation, morphology and genetics which will assign them to childreni rather than maculosa, and if you really want to you can knock yourself out and research it all.

Yes, they all hatch with pattern. The pattern is lost gradually as they grow, starting from when they're babies, and finishing generally by about 1-2 years or so depending on how quickly they grow, which depends on how much they eat. Some completely lose their pattern, some retain a faint pattern. I've never seen a boldy patterned adult Elcho Island Children's Python, but it's possible, and if you really wanted to you could probably selectively breed them to be fairly boldly patterned (which would be a pretty stupid thing to do).

It's not a strain or morph or breed or species, it's a locality. Elcho Island is a place, a big island off the coast of the Northern Territory.

As far as size, breeding, feeding, etc. etc. goes, they're pretty much typical Children's Pythons. They have their own distinct feel to them and quirks, but no more than any other locality of Children's, and it's all pretty subtle other than the colour and (lack of) pattern. The main appeal to me at first was that they come from a specific locality, an island. After raising my first pair I came to love their appearance, and bought about half a dozen babies the following season. I still have a few of those original animals and they're still among my absolute favourite snakes.

Books aren't going to mention them. They're not going to mention any specific island populations, they tend to mention few if any locality variants of any species of reptiles.

 

[Gruni]

Thanks for that Sdaji, the image of the hatchy I initially saw didn't 'seem' to have that stimi strip to it, but then again it was fairly curled up and YES I am fairly new to snakes. Being an isolated locality it makes you wonder if they are somehow more true to the original species.

Somebody in the other thread suggested there was some division of particular scales, or lack there of, that differentiated the Childreni from the other Antaresia but I am not that keen to fully look into it.

If you look at the pics in Billy's clasified his hatchies seem to have lost there pattern quite quickly but either way the dark gleem of the adults is certainly striking, and I say that as someone who isn't a big fan of the standard looking Childrens python.

 

[Sdaji]

I saw the pictures after posting what I did above. You can't see the stripe because of the snake's pose, but the pattern totally screams of Children's and is a typical Elcho pattern (which will probably become completely obscured as an adult). You wouldn't generally get any of the 'typical' localities of Stimson's looking much like that, but the difference is more subtle. Once you get familiar with them all you would never mistake that Elcho for a Mac, they're chalk and cheese, you just won't get a Mac with blotches like that (unless it's a freak).

The scale division thing might sometimes sort of work, but certainly not reliably. These things freely interbreed in the wild, remember? There is absolutely no reproductive isolation along the border between 'Children's' and 'Stimson's'. It's a bit like black on the north coast, white on the south coast, shades of grey everywhere in between, and someone arbitrarily drew a line somewhere, based on how distinct the patterns are, and called everything north of that line one species and south another species. If they wanted to they could have put that line somewhere else. Anywhere near that imaginary border you'll find snakes intermediate between typical Stimson's and typical Children's, and the snakes themselves don't care if they mate with something more or less strongly contrasting. If you have to assign something grey as either black or white, what is it? It's not like any particular trait suddenly stops along that line someone drew in the sand, whether colour, pattern, size, scalation or anything else.

Being isolated on an island doesn't make things true to any original thing. There are Antaresia on lots of islands, and they certainly don't all look like Elchos. If anything they tend to evolve off in their own direction and look a bit different from other things, not just sit there without ever changing and looking like something ancient.

 

[waruikazi]

Gruni defining different species isn't an exact science and it is easy to get lost in how and why species are separated. It's something i used to get quite caught up and confused about too because describing species and sub-species can seem to be very arbitrary.

We need to remember that all species are still evolving and changing, we just happen to be looking at them in their current state during our current time and trying to decided where they fit. If we consider snakes (because we are herpers) there are a myriad of species that have different populations, some even sharing the same habitat, that are significantly different to each other yet they are still described as the same species. Case in point are the Northern Death Adders (A. Praelongus) woodlands and floodplain phase, one grows significantly longer and more robust yet still considered the same species. Another is the childrens (A. Childreni) there is a lowland or woodland phase that also grows quite long and robust and a highlands or stone country phase, that grows much shorter and is less robust (even a novice would probably see the difference). In the case of the childrens i know there has been some genetic work done on them and they cannot be separated genetically despite the obvious visual difference.

The best explanation for this change (i hope Sdaji agrees with me, he is much more across species and genetics than i am) is that these species are going through a stage of evolution where they are changing but aren't quite a different species yet.

So what makes a mac different from a childrens? Not much! But a herper was able to find the small differences that are unique to each and make an argument robust enough to have their peers accept that they are different species.

 

[Sdaji]

Sometimes you can see cases where one species is going to become two species in the future, but it hasn't happened yet (perhaps the Death Adders are a good example where geographic isolation isn't a factor). If the Elcho Island Children's Pythons were isolated for long enough they would eventually become a different species, but for now they're quite clearly Children's Pythons. Whether or not they do become a different species will depend on whether or not they remain sufficiently isolated. We'll know in a few million years.

Then there are grey areas based on geographic distribution. Something like Morelia spilota bredli. Some people already consider it a different species, which I personally think is absurd, but if the climate never changed it probably would become a different species. If the climate allowed Morelia spilota to expand its range and the bredli population contacted metcalfei or variegata, speciation would not occur. To call it a different species now based on the future possibility of it becoming a different species in the future based on climate speculation seems even more silly than naming things different species just because they're on islands or otherwise geographically isolated.

Some people use reproductive isolation (either biological or geographical), some use DNA, some use phenotype... the reality is that none of them always works, and there will always be examples which totally throw you. Pretty much all pythons *can* interbreed and make fertile babies, even though they're clearly different species and genera. The fact that they don't do it in the wild even though they're sympatric says to me that they're obviously different species (along with the obvious morphology differences). Almost always, if things do routinely interbreed in the wild (like Children's and Stimson's) it's totally stupid to call them different species, but we do that often for some odd reason. Relying on DNA % differences is now very common, but it's one of the most stupid tools in the box (at least as it tends to be used). With a complex situation like speciation, basing a decision based on an arbitrary % difference is nonsense, but it's now very popular. It used to bother me how poorly it was all done, you could rant and rave and write several books about it, people would still disagree, people will always argue about how the terminology should be used, but at the end of the day it generally doesn't affect the animals too much. No point losing sleep over it, I stopped fussing about it years ago and just accept it's one of the countless things people do badly :lol:

I think Macs being different from Children's is a pretty obvious one. Not necessarily full species, but at least subspecies. There is a very large population on the east coast which is quite distinctly different from the even larger population immediately on the other side of a large geographic barrier (the Great Dividing Range). There are obvious differences with sharp contrast, obvious reasons for it, geographic isolation (almost total). Personally, I'd call that a great example of where 'subspecies' would be appropriate, since if they do meet up, even in natural conditions, they'll freely interbreed. Given another few million years they'd probably become difference species, but they're not there yet. If up in Cape York they were living side by side with Stimson's and not interbreeding, yep, full species would be appropriate.

Anyway, many (most, simply because they follow whatever the published books say at any given time - back in the early 80s everyone would have called them all the same subspecies because that's what the books said) people would disagree with me, and that's okay, the animals are going to fuss over it less than any of us.