Saturday, June 30, 2012

My Take on Temporalis

There's a secretive snake which inhabits the coastal plain of southern New Jersey that is one of debate and ongoing research, the Coastal Plain Milk Snake. Very little is known about this species of snake, from its ecology to something as simple as exactly what it is. Coastals were once a valid subspecies of the Eastern Milk Snake; Lampropeltis triangulum temporalis, but Kenneth L. Williams and several other researchers determined that this snake was simply an intergrade between the Scarlet Kingsnake and Eastern Milk Snake and thus that its subspecies status was not valid. However, this snake does not share its range with the Scarlet Kingsnake in the New Jersey pine barrens. Which begs the question, what the hell?

Coastal Plain Milk Snake - Lampropeltis triangulum "temporalis"

This beautiful coastal was found under cover on a damp, humid morning this weekend in the New Jersey pine barrens. Like many other milk snake species, coastals are secretive and not often found active on the surface. They can be found under all sorts of cover throughout the pine barrens and are particularly fond of the sandy soils which are prevalent in the New Jersey coastal plain. But the biggest question regarding coastals is, what are they? The answer is to that question is still in limbo.


There are several different hypotheses involving the identity of coastals. The one made by Williams which states coastals are simply intergrades between Eastern Milk Snakes and Scarlet Kingsnakes is partially true, but only where the two species ranges overlap, particularly in Virginia and North Carolina. It is likely that both coastals and SKs are found in the coastal plain of these states and occasionally intergrade, not making the coastal an actual intergrade between the two a valid explanation for the snake rangewide. Others feel that coastals are a relic population of the Red Milk Snake (Lampropeltis triangulum syspila) which occurs in the coastal plain. Many people I've talked to argue that if you put a red next to a coastal, you wouldn't known which snake was which. However, there's more to it than simple phenotypic similarities. Certainly both reds and coastals share a recent comment ancestor in terms of their evolutionary historu, but whether or not the coastals are simply red milk snakes requires much more in depth DNA analysis, which I'm told is currently progress. Personally, I tend to think that these snakes are simply a beautiful regional variant of the Eastern Milk Snake which happens to be isolated to the coastal plain of New Jersey, Maryland, Delaware, Virginia, and North Carolina. Just like the canebrake rattlesnake and timber rattlesnake, coastals just happen to look a little bit different than easterns. Regardless of what they are, coastal plain milk snakes are a beautiful member of New Jersey's herpetofauna which are in need of protection to ensure that more scientists can argue over what they are for years to come.


3 comments:

  1. From what I've heard through the rumor mill, there is some going on currently.

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  2. If there is no genetic evidence proving a direct genetic relationship, then by what scientific evidence do you claim that "both reds and coastals share a recent common ancestor in terms of their evolutionary history"?

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