Thamnophis sirtalis pallidulus controversy.................

[Snakers]

The maritime garter snake, a very little known species of the garter snakes has been brought up several times throughout this forum. The real controversy is should this "species" of snake really be a subspecies? I myself think it is any ordinary eastern garter snake without the back stripe, I'd like to here other peoples opinions on this snake.

[ConcinusMan]

It is a subspecies of Thamnophis sirtalis. Hence the third name. It is distinct morphologically and geographically from eastern garters. That qualifies it to be a subspecies.;) But yes you are right, it is basically just an eastern garter, it's just that it is genetically distinct and geographically separated. That is all that is needed to qualify as a subspecies.

[Stefan-A]

That they look similar, does not mean that they belong to the same subspecies. It could be an indicator that they do, but it's not evidence for it by any means.

The only rational position on this issue, is on the fence. Provided of course that there isn't a paper out there dealing with this exact issue and answers that question by referencing DNA evidence.

[ConcinusMan]

Interesting in depth article on maritimes here:

Ecology and Morphology of Thamnophis sirtalis pallidulus (Maritime Garter Snakes) on Georges Island, Nova Scotia | Northeastern Naturalist | Find Articles at BNET (http://findarticles.com/p/articles/mi_qa3845/is_200601/ai_n17183702/)

[Stefan-A]

Interesting in depth article on maritimes here:

Ecology and Morphology of Thamnophis sirtalis pallidulus (Maritime Garter Snakes) on Georges Island, Nova Scotia | Northeastern Naturalist | Find Articles at BNET (http://findarticles.com/p/articles/mi_qa3845/is_200601/ai_n17183702/)
I skimmed through it. Doesn't say much about the subspecies, just some interesting observations about the Georges Island population.

[ConcinusMan]

Yeah, well I had it bookmarked and thought it was interesting.

[Stefan-A]

Well, it is interesting. :D

[ConcinusMan]

The Melanistic Garter Snakes of Georges Island (http://museum.gov.ns.ca/mnh/nature/snakes/melanist.htm)

[Tyrel26]

Thats the link I brought up a while back; since then I contacted the guy that did the majority of the studies and he was far from helpful. I asked a couple questions but when I got a reply from him he had ignored my questions and said that if I find a melanistic garter snake he wanted it.

[Snakers]

The thing is how can we state that the "maritime" garter snake is not just an eastern, i have caught several easterns that are nearly identical to a so called maritime but yet im out of their range............What i'm trying to say is that we don't have enough evidence that the Maritime is not just an eastern.

[ConcinusMan]

The thing is how can we state that the "maritime" garter snake is not just an eastern, i have caught several easterns that are nearly identical to a so called maritime but yet im out of their range............What i'm trying to say is that we don't have enough evidence that the Maritime is not just an eastern.


True. However, the Georges Island population reminds me of the case of Sceloporus occidentalis on some of small islands off the coast of California. They are just western fence lizards but they have been isolated from the mainland population for so long, and at one time the gene pool on the islands was so small, eventually the island lizards look so much different than the mainland lizards, and obviously have a distinct range, that they became a separate subspecies over time.

Something similar has happened to Carpodacus mexicanus, The western house finch. It was introduced to Hawaii and it's decedents are completely different both in behavior, range, AND looks. Also, birds here in WA only nest in dense evergreen shrubbery. That fine because they are seeking protection from crows and jays which are abundant here. In CA and NV they only nest on building ledges because the main predators there are snakes, something that isn't a problem here in western WA. Also, their colors are different, helping them blend in with the very different landscape and vegetation.

My point is, maritime garters ARE easterns but they are distinct enough in range, and dominant phenotype that it qualifies them as a distinct subspecies of Thamnophis sirtalis. The fact that there are some easterns that look like maritimes isn't surprising at all but looking like a maritime isn't necessarily the dominant phenotype within the eastern garters range.

[Stefan-A]

What i'm trying to say is that we don't have enough evidence that the Maritime is not just an eastern.
The currently available evidence against them being just easterns, does seem to be based on morphology, which, incidentally, is the same thing you're citing as evidence for them being easterns. :D

But I'll save my verdict until they've actually been tested.

[ConcinusMan]

the currently available evidence against them being just easterns, does seem to be based on morphology, which, incidentally, is the same thing you're citing as evidence for them being easterns. :d

d'oh!

http://images.hollywood.com/site/homer-simpson.jpg

[BUSHSNAKE]

figuring out the differences between the sirtalis subspecies is something ive been researching for some time now and i havent learned anything cuz the only difference between similis,fitchi,pickeringii etc. is color,pattern and range.

[ConcinusMan]

Believe me, the debate and questions have been going on longer than both of us have been alive. The technology to answer most of the questions now exists. The problem is, nobody is doing anything about it. It takes money, a lot of DNA samples and years of travel, collecting, lab time, and research. Some limited research and DNA sampling has already been done. You would think that infernalis, tetrataenia, and concinnus were closely related based on morphology and range, but DNA sampling reveals otherwise. They are both more closely related to other garters that don't even look similar, found far from their range, than they are to each other!

[BUSHSNAKE]

i enjoy taxonomy very much but its more like politics then science

[BUSHSNAKE]

did you see what happened to the kingsnakes recently?

[ConcinusMan]

Exactly. Right now our knowledge of garter snake taxonomy, even as quoted by the worlds top authorities, and pretty much taken as truth, would be revealed by DNA testing to be totally wrong. Could be that maritimes and easterns aren't closely related but only look similar due to convergent evolution or a local tactical advantage (natural selection) We can debate all we want but until the DNA testing is done, it's all just opinion.

[Snakers]

did you see what happened to the kingsnakes recently?
what happened?

[Stefan-A]

i enjoy taxonomy very much but its more like politics then science
I don't know what happened with the kingsnakes, but I have seen what happened with Elaphe. That genus got chopped up for good reason, yet there are people out there, who are reluctant to accept it, sometimes for reasons that have little to do with the actual relatedness of the species concerned. Same thing with the North American rat snakes. There was a huge outcry when they were "reorganized" a few years ago.

I think there are a few people getting involved in the process, who have lost sight of what taxonomy and classification is supposed to be. Naturally, the fact that there are so many different ideas of what constitutes a species, can also turn something like classification into politics (a horrbile dysphemism).