The locality debate

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The locality debate

Post by morelia on Sat May 22, 2010 11:17 am

I thought a separate thread would be good to tease out people's thoughts on locality animals.....is it important to source and keep locality animals? Or should we just say screw it, they're all in captivity and so does it really matter?

Below is my take on it - apologies in advance for the essay, but this stuff interests me a lot.

IMO 'locality' animals in the hobby can be divided into 2 main groupings according to the circumstances under which they are found in nature - those that are more deserving of being assigned a locality name as they are quite distinct geographically, and those which may be distinct but are not geographically isolated as such. To demonstrate what I mean here, lets use the subspecies Boa constrictor imperator (BCI) as an example.

BCI distribution & natural variation
Look up a distribution map for BCI and it you'll see it covers a wide area from northwestern South America (west of the Andes) and most of Central America. Being found over such a large area means that it must have been able to respond to changes in habitat and climate to expand over the area it has today - so BCI is an adaptable animal. Part of this adaptable nature is manifested in slightly different outward appearances over its geographical range - just as we see in other species which have a wide distribution area.
These slightly different physical appearances spring up as part of the natural variability in the appearance of BCI, and may become more common in certain areas of the distribution range. This leads people to assign 'locality' names to these animals which have a particular appearance. Thats grand, but here is where I draw my distinction.....

Geographically linked 'locality' animals
If such a locality animal is NOT geographically isolated in some way from other BCI populations, so gene flow can occur. This means that, while animals in one area such as northern Nicaragua can have a certain appearance, there is nothing to stop animals with the same appearance popping up in southern Honduras which is just a short hop away....so are animals with this appearance 'Nicaraguan' or 'Honduran' boas? LOL.......as Tony has already said, animals don't recognise political boundaries. Its in these instances I believe that the term 'locality' animal can be a little misleading as people expect them ALL to have the same, fixed appearance. In reality this doesn't happen due to gene flow with other BCI populations. I would personally call these animals VARIANTS of BCI as nothing isolates them sufficiently to fix their appearance as distinct from other BCI populations. They may be smaller or darker or lighter than the familiar Colombian form, but due to gene flow with other populations these differences are not absolute.

Geographically isolated 'locality' animals
However if they cannot mix with other BCI populations due to GEOGRAPHIC ISOLATION i.e. unsuitable habitat isolates a BCI population, then over time this isolated population starts to take on its own appearance and natural history which is amplified due to lack of gene flow with neighbouring populations. This produces boas with appearances and traits that are more fixed and absolute - so Sonoran Desert dwarf boas are true dwarfs and are dark in colour, an adaptation to their cloud forest habitat; Hog Island boas, Crawl Cays, Caulker Cays, Corn Islands.....all are geographically isolated and so their appearances are quite distinct and more 'fixed' due to lack of gene flow. I would call these animals LOCALITY BOAS as they are a truer representation of their area of origin.

To summarise.....
Some of these boas have diverged from the BCI main distribution area for so long that they may warrant being described as distinct subspecies - Warren and RMG would know a lot more about this than me - and this starts other long-standing debates as to exactly what a subspecies and species are! The debate will run and run and run.....in the end, its all man-made waffle that puts animals into pigeon holes (some more deserved than others) in an attempt to categorise and understand the natural world.

For me, owning a locality animal with a lineage that is traceable back to founder stock from the wild, is nice for my enquiring mind.....its nice to know why an animal looks the way it does and why it acts the way it does. I also own animals that are intergrades or have an untraceable history, so I'm not a 100% purist, but I do like wild type animals preferentially.

As keepers and breeders I believe the responsibility lies with us to either breed true or, if we mix animals from different areas, to be 100% honest about their origins and pass this on to the buyer / next owner. A pure Diamond python is nice, very nice, but many Diamond x Jungle python intergrades are very nice too...as long as some twit doesn't try to sell an intergrade as a pure Diamond python :)
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morelia
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Re: The locality debate

Post by Tony W on Sat May 22, 2010 11:50 am

Karl,

Outstanding post , articulated in fine fashion, I've had my say in the other post, and again am in 100% agreement that those animals that are true locality boas are those that develop/evolve over time in relative if not complete isolation....
....here's a point I'd really like your opinion on Karl....if we truly believe the latter....why haven't the "true" locality boas been given there own sub species status? And of course I'm talking about the Sonoran and island variants, I know you're not into the pigeon holing thing, but so many are, and you would of thought that a few of the current BCI group could be given their own status....
I can see it now in neon lights.... Boa constrictor karlimus.....oh, erm...that would be the Crawl Cay!! Very Happy

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Re: The locality debate

Post by Warren_Booth on Thu Jun 10, 2010 9:59 pm

I will post a response to this in a day or two. I am up against the wire on a manuscript submission (snake related in fact), and I want to get it submitted before I head back to Belfast for a vacation on the 15th. Good post, and I promise I will put together a nice response.

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Re: The locality debate

Post by Tony W on Thu Jun 10, 2010 10:03 pm

Warren...this is great and looking forward...I'll not be home then, but do have a great vacation....

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