Moved off the road

[Berkeley]

Oops- I noticed a typo in my response above the pictures in my previous post.
It says the "animals are quite fully sized".

It should read that the "animals areN'T quite fully sized"

Sorry for any confusion.
--Berkeley

 

[tglazie]

You and I may also have to agree to disagree, Berkeley, because Mark is absolutely correct. There is no way in Hades that is a red eared slider. Now, I contest Mark's notion that slider's don't get that big. The biggest one I've ever grabbed was fifteen inches in length and too big around to fit in an orange Homer bucket. She also had six fish hooks in her mouth. She was a real beast. That being said, the animals you've shown in the photo don't have smooth rear marginals. They're clearly serated. Whether they're serated or not, though, has nothing to do with differentiating sliders and cooters, given that both have serated rear marginals. Painted turtles are the smooth fellas on the block. And you said so yourself in the correction that they weren't full sized, which is precisely why the patterns are more blotchy in nature on the older animal in question.

The one thing that was, to me, the dead giveaway was the serated jaw, used for tearing at plants, which you can clearly see in the first photo. I've seen many red ears in my day, having fished them out of a dam on the San Antonio River on countless occasions, and I've never seen one with a jaw like that. Now, you could argue that the jaw line was damaged, but I've never seen damage quite like that, and I've seen a lot of damaged jaws. One red ear male I fished out of the spillway five years ago had a jaw that was shorn in two by a fish hook (and it was an old injury, which really shows how truly awesome these guys are at surviving trauma).

As for the leg markings, this animal doesn't possess what I've found to be the dominant characteristic of animals in the area, namely the two robust, unbroken stripes that line the front legs. This animal has interruption and deviation of those stripes. There's also the color. Judging by this animal's scuffed plastron and size, I would say it's at least ten years old, at the very least, and probably older. All sliders I've seen at that age tend not to have much coloration at all, tending toward a uniform melanism on the head and face. This animal still has a large amount of it's luster, something I've found rather typical of large Guadalupe and Rio Grande cooters.

Ultimately, we must simply agree to disagree. I'm sure you have a great deal of experience with these animals, from the way you make your case. All I'm saying is after having spent decades living in South Texas, after having spent decades dealing with wild turtles throughout San Antonio, the Hill Country, and the valley, all of my instincts are telling me that this is a cooter. It really is too bad that we can't see the animal with it's head fully extended so that we can put the controversy to rest.

T.G.

 

[Berkeley]

Hey T.G.-
That is okay, we can disagree too! I don't mind!

I do agree though that it is unfortunate that we can't see better pics of the head, that would definitely make a positive ID. I also agree that big female sliders get much bigger than had been stated. I've seen some monsters! I do have years of experience with the pond turtle group, having worked with and kept thousands of sliders and cooters of various species and subspecies. And I can tell that you do too- we've got a good discussion here! However, I will be the first to admit I have never caught a wild gorzugi (heck, I've never even gotten to go to Texas). But I still think this is a red ear. Allow me to clarify.

I didn't say that cooters had smooth rear marginals- I said that "they would be more smoothed out" when compared to sliders. Sliders tend to keep a pronounced serration, whereas the cooters lose the real defined serrations.

In regards to the serrations on the jaw, you can't see any in the picture of the face. What is evident though is the cusp or notch at the front of the beak (it's not an injury)- but that is not a telling characteristic because it can be found in both groups.

Finally, looking at the pattern on the underside of the front marginals, they are dramatically different from what I would call typical of older gorzugi and more in line with what is seen on older sliders. Here is a cropped in version of the original picture of the animal in question.

You can see the dark markings against the light background pretty well. The dark markings are fine, and peppery.

Contrast that with these pictures of an older gorzugi with the faded and broken up pattern and a big difference is evident. The pattern here is wider, scribbly, and almost as if a worm crawled through the black, leaving the colors exposed. A very different look. (Not my pictures; again, taken from the internet. Credits, and my apologies to the photographer)




Those are my thoughts. I still think it is a red ear; but as you stated, without better pictures of the head we will never be able to put the controversy to rest!

--Berkeley

 

[tglazie]

Apologies, Berkeley, but I remain unconvinced. Now, perhaps I spoke a little forcefully in saying that there was "no way in Hades that is a red ear," and I certainly may have mischaracterized your comparison of the rear carapacial serrations. But I have to say, also, that the animals you've shown in pictures appear quite different from many of the creatures I've come across here in South Texas. Now, truth be told, I don't tend to venture too far west along the Rio Grande, and I can say that many of the more colorful turtles I've encountered tend to come from the Rio Grande valley proper. However, I've also encountered many a cooter extending all the way up into the hill country (probably the area with which I am most familiar) in the more northerly tributaries of the Guadalupe River, and I've seen many a cooter that fit the profile of this animal. The picture in the following link maintains closer resemblance to the animals I've encountered in my neck of the woods, and to my eye, the markings match up. http://www.chrysemys.de/Fotos/Schil...as/Pseudemys gorzugi/Pseudemys-gorzugi-01.jpg

The markings on the front legs are reminiscent of cooters in my area. Now, I don't know the precise geographic origin of the cooters in your pictures, but having seen the wide variety of forms that claim the name Rio Grande Cooter or Texas Cooter and having seen the incredible variation among Red Eared Sliders (the Texas Ornate sliders, also known as the Rio Grande sliders are something to behold; I personally feel they are without equal, with their wide, bright yellow carapacial bands and their bright crimson "ears"), I must say, it doesn't surprise me in the least that these pics, with their limited detail, would create a certain amount of controversy.

Unfortunately, we don't have a head shot of this animal, as you and I have both pointed out, making a conclusive and decisive identification likely impossible. But as someone who has encountered these animals on a fairly regular basis, I stand by my determination until a definitive head shot could budge me to think otherwise, which isn't going to happen, so I suppose I'll just have to sit here and be stubborn. But hey, like I said, I'm just a fella who likes turtles. I could very easily be wrong.

T.G.

 

[Berkeley]

Valid points about the variation of individuals across range, T.G. As you mentioned, since the pics I used were just 'generic' gorzugi without specific locality info, they may very well be from a different drainage or something. Who knows!

Without a different, full head shot, it will be impossible to definitively ID the turtle. I could very easily be wrong as well. I appreciate the discussion we've had- good points all around, I think.

Separately, I got to see some Rio Grande sliders over the weekend in person, and holy cow! I had forgotten how nice looking they were! It had been a few years since I had seen them. What a treat that was!

Anyhow, I've enjoyed it. Looking forward to more posts!
--Berkeley

 

[keepergale]

What a polite and erudite discussion. I know nothing about this turtles and still found this interesting.