Reptile & Amphibian Forums

Since winter is starting in earnest here in MI, and I have these photos I'm uploading to the Ratsnake Haven gallery, I thought I'd do a little photo comparison of a few species that are often compared to each other, just for the fun of it. Plus I wanted to see how long of a sentence I could make..haha.

Ok, let's start with a group of female Chinese twin-spots, Elaphe bimaculata, sometimes called the Chinese corn snake, sunning themselves after a long brumation last winter...

The portrait of a Western Great Plains Ratsnake, E. e. "intermontana"...

A Northern Great Plains Ratsnake, E. e. "emoryi", showing the ventral pattern...

A Southern Great Plains Ratsnake, E. e. "meahllmorum", showing the ventral pattern, or lack of...

Portrait of a Brazos Island Ratsnake, E. e. "meahllmorum"...

And finally, a shot of a gravid, striped leopard snake, Elaphe situla, sometimes compared to the corn, or the Chinese twin-spot...

Like I said, "just for the fun of it". Actually, I wanted to show the ventral patterns of the emoryi, because of some discussion of identification characteristics a few days ago. Sorry if you've seen some of these pics before, but I wanted people to be able to do some comparing. Hope it wasn't too much a waste of space...LOL. TC.

Ratsnake Haven Gallery

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Ratsnake Haven: Elaphe schrencki, dione, bimaculata, mandarina, conspicillata, porphyracea, taeniura, situla, and emoryi.

You see some questions on what you've shown several times each year. Thanks for taking the time to illustrate some of the answers. Nice pics. Some of the answers relating to corns and other species concern the ventrals. It's great to see some comparison pics like you've posted. I sometimes still have difficulty between the diones and bimacs. Some are clear cut, but there's some that are tough to call. This bimac is getting ready to shed. Mine seem to darken prior to shedding.

Terry Parks

Nice browns in that bimac of yours.

I think one of the points of my post was that the more we get to know the snakes the more differences we see in them. When I first got bimaculata and dione from Lloyd Lemke way back in '96, I could barely tell them apart. It was superficial though. As I got to know the snakes, their differences in behavior were apparent. Some dione still remind me of bimaculata, but most of them look like a different snake. There's so much variety with dione and I'm finding quite a bit with bimacs too, there's bound to be some overlap in characteristics.

I think when comparing the three species above, bimaculata, emoryi, and situla, there are some obvious differences. I used to think bimaculata and situla were closely related, and not too far distant from some American ratsnakes, in spite of being on three different continents, Europe, Asia, and N. A.; but in the past year, or so, I've started to notice many differences. The American corns and Great Plains ratsnakes aren't much like the Eurasian ratsnakes at all. To a novice, the Eurasians may seem to have an initial resemblance to guttata/emoryi, as they did to me in the beginning. But now I know how distinct each species is. This has been one of my main goals all along and I feel like I've made some good progress along these lines.

Recent taxonomy has made situla and bimaculata quite distant, btw, maybe even more distant than bimaculata to emoryi/guttata. If Utiger et al.'s recent proposals stand up to further scrutiny, we may not even be able to put any of them into the same genus. At any rate, they are very interesting species, and more and more info about them should become available as time goes by.

In the meantime we keep plugging away with these guys. More later, I'm sure....

TC

> Actually, I wanted to show the ventral patterns of the emoryi, because of some discussion of identification characteristics a few days ago. Sorry if you've seen some of these pics before, but I wanted people to be able to do some comparing.

The Brazos ventrals are unusual in their lack of ventral checkering. Although all populations of meahllmorums I've seen tended to have some individuals with almost no ventral checkering, many have plenty, but not as much as "emoryi" does on average. However, some even have as much as the typical "emoryi." Be REAL careful using ventral pattern on emoryi unless you know exactly what to look for (blotch shape, position, coherency, sequences, and counts).

Additionally, coastal populations - except the Brazos Islands - tend to be more heavily checkered than others in the US - even more than northern emoryi. I am pretty sure that I know why that is (intergrade artifact), but they are only found on one section of the gulf coastal plain in the US, so the sample size is too small to make any strong conclusions. Of course, intermontana will depend on which valley the parental stock came from.

Emoryi kick guttata butt!
KJ

KJ,

I assumed there'd be some variation, but I didn't know how much, since I'm fairly new to the emoryi. Since I've seen some northern emoryi with ventral patterns and meahllmorum with very little, I was guessing there might be some clinal variation. Even if there are tendencies which are fairly common, it might help to guess what part of the country the snake came from.

BTW, that coastal population you mentioned, is it isolated or part of the northern population? Maybe it has a strong influence from guttata rather than emoryi.

I know hardly anything about the "intermontanas". Just that they are associated with the Colorado and Green River drainages. But I've also heard that they are a fairly high elevation snake. Maybe they inhabit plateau areas as well as river basins. Care to add any info on these mysterious critters?

TC

>>Since I've seen some northern emoryi with ventral patterns and meahllmorum with very little, I was guessing there might be some clinal variation.

There is, but there are WAY too many exceptions to use that as an identification marker without a lot of reservations.

> Even if there are tendencies which are fairly common, it might help to guess what part of the country the snake came from.

Yes. Well, no....lol. Seriously, it helps if taken in consideration with OTHER characteristics. Blotch count is more consistent, but is useless in the supposed "meahllmorum X emoryi intergrade zone." It is a big fricken zone, too. Like in guttata, you can't ID MOST localities just be looks.

>>BTW, that coastal population you mentioned, is it isolated or part of the northern population? Maybe it has a strong influence from guttata rather than emoryi.

Nah, it is just further up the coast from the Brazos Island ratsnakes. Now, I'm sure you can guess my hypothesis. You'll KNOW what it is when Vaughan's paper comes out. One of my animals from that area is in her studies, but it isn't an emoryi. hint, hint. LOL.

Shut up, Terry Parks - you know what she is, huh?

>>I know hardly anything about the "intermontanas". Just that they are associated with the Colorado and Green River drainages.

They are more wide-spread than that, or at least not TIGHTLY associated with just a couple of river drainages. i'm not sure how you mean it. If looking just at the CO ones, we may be saying the same thing, but in two different ways.

KJ

(12-3-03) > Actually, I wanted to show the ventral patterns of the emoryi, because of some discussion of identification characteristics a few days ago. Sorry if you've seen some of these pics before, but I wanted people to be able to do some comparing.
TC

The Brazos ventrals are unusual in their lack of ventral checkering. Although all populations of meahllmorums I've seen tended to have some individuals with almost no ventral checkering, many have plenty, but not as much as "emoryi" does on average. However, some even have as much as the typical "emoryi." Be REAL careful using ventral pattern on emoryi unless you know exactly what to look for (blotch shape, position, coherency, sequences, and counts).

Additionally, coastal populations - except the Brazos Islands - tend to be more heavily checkered than others in the US - even more than northern emoryi. I am pretty sure that I know why that is (intergrade artifact), but they are only found on one section of the gulf coastal plain in the US, so the sample size is too small to make any strong conclusions.

Emoryi kick guttata butt!
KJ

(12-6) >>BTW, that coastal population you mentioned, is it isolated or part of the northern population? Maybe it has a strong influence from guttata rather than emoryi.
TC

Nah, it is just further up the coast from the Brazos Island ratsnakes. Now, I'm sure you can guess my hypothesis. You'll KNOW what it is when Vaughan's paper comes out. One of my animals from that area is in her studies, but it isn't an emoryi. hint, hint. LOL.
KJ

(12-7) Ok, you said it was an "intergrade artifact" and it isn't an emoryi. You must mean some type of Kisatchie Corn Snake from like Galveston County, or other. If it was further south, it would be "meahllmorum", wouldn't it? Am I far off? Post an answer or e-mail me please. Thanks for the addtional info, and let us know when Vaughan's next paper comes out too.

Later....TC.

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KJ

Great pictures - thanks for posting - it is really nice to see comparison photos. I didn't realize there were so many locality specific Great Plains ratsnakes.

mary v.

>>I didn't realize there were so many locality specific Great Plains ratsnakes.
>>
>>mary v.

Thanks, Mary. Interest is up some in the past few years and the localities are coming out. There are a fair number, and should give emoryi as many localities as guttata eventually. However, the majority of specimens and morphs of emoryi are from the northern form, Elaphe emoryi "emoryi". Not that many people keep the other forms, like "intermontana", "Brazos Island", and other southern forms (E. e. "meahllmorum" yet. But that may change in the near future.

Good luck....TC.