Range of crotalus atrox and scutulatus

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RobertH
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Range of crotalus atrox and scutulatus

Post by RobertH »

I just found a picture on the Internet of what looks like either c. atrox or c. scutulatus. Either way, the location where it was (reportedly) found surprised me. The snake was found in a place that, from what (little) I know, is too far West for c. atrox and too far South/low elevation for c. scutulatus.

Since I don't want to get too specific, let me ask my questions this way:

What is the westernmost reported range of c. atrox?

What is the southernmost reported range of c. scutulatus?

Thanks,

Robert
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Fundad
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Re: Range of crotalus atrox and scutulatus

Post by Fundad »

Atrox are rumored (I think there might be some historical records to back it up) to be found way up into the west side of the coachella valley, though I have only seen them from mid valley east..

Fundad
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monklet
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Re: Range of crotalus atrox and scutulatus

Post by monklet »

Brian, are there any WDBs in JT?
RobertH
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Thanks, Brian.

What about scutulatus in the southwestern Coachella Valley?

The snake, to me, actually looks more scutulatus than atrox. But I am basing that mostly on the tail rings (irregular, more white than black). I can't make out the scales between the supraoculars. The exact location of the side stripe is also hard to tell.

Robert
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Fundad
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Re: Range of crotalus atrox and scutulatus

Post by Fundad »

@ Monklet Yes in certain areas...

@ Robert no 'known" Scutes in that area.. Can I see a pick of the snake in question?

Fundad
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PNWHerper
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Re: Range of crotalus atrox and scutulatus

Post by PNWHerper »

Out of curiosity, are there habitat or mico-habitat preferences that are different for the 2 species where their ranges overlap? Or tendencies, even?
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

OK, here is the picture. Took me a while to figure out how to download it to my PC and then upload it to my web album.

Image

So, whaddaya think? Scute?
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Fundad
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Re: Range of crotalus atrox and scutulatus

Post by Fundad »

Atrox 100 percent

Fundad
RobertH
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Cool, atrox, huh?

Even though it appears to be not quite a range extension, I now wonder whether and when atrox was last recorded in that area (northern slopes in the western Coachella Valley). Maybe Fieldnotes will chime in later.

If it turns out to be a notable find, I would be able to contact the people who saw and vouchered the snake. I already know the date and exact location via their blog post. Maybe, we could get it entered in the database that way.

In any event, with another cool weekend on tap here in LA, I think Nicholas and I are going to pay a little visit to the low desert Saturday. I know it's bit earlier in the season, but it's supposed to be 80 degrees in Palm Springs and, who knows, maybe we will find an atrox there ourselves ... or at least a Banded Rock Lizard :D

Robert
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Kent VanSooy
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Re: Range of crotalus atrox and scutulatus

Post by Kent VanSooy »

Robert, I'm going to share (aka steal) some really helpful tips from Kris in AZ...

Perhaps the greatest differentiating characteristics have to do with the head.

1) In C. s. scutulatus, there are 2-3 LARGE SCALES between the supraoculars...I have yet to see an animal with greater than 3.

In C. atrox, there are numerous (USUALLY 4-5) SMALL SCALES between the supraoculars.I have never seen an animal with less than 4.

2) In C. s. scutulatus, the rear of the eye stripe GOES BEYOND the rear corner of the mouth.

In C. atrox, the rear of the eye stripe does NOT.

3) (Hopefully) you will also notice the "chunkier" head of C. atrox. Seen in real life, they are quite "blocky" and thick.

In contrast, the head of C. s. scutulatus is much more "elegant" and "arrow-shaped".
RobertH
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Thanks, Kent. The main distinguishing characteristics - in theory - are clear to me from CalHerp. But never having seen an atrox before and not enough scutes, I couldn't be sure by looking at the picture. The scales between the eyes and also the exact position of the eye stripe are unfortunately hard to see on pictures and possibly even in the field.

Two things I have learned from this little exercise, though, is that the tail rings are not at all determinative. That's good to know. The chunkier head was also news to me. I'll keep that in mind.

Robert
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Fundad
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Re: Range of crotalus atrox and scutulatus

Post by Fundad »

Image

From the mid to western c valley area..

Fundad
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

I just called that place up and talked to the ranger. It turns out that he's personally never seen atrox there, only ruber. Then again, the rangers at the park in Santa Clara where we found 20 sirtalis infernalis within 2 hours had NEVER seen ANY there. :lol:

Still, this ranger seemed knowledgeable enough, telling me that he had seen garter snakes, gopher snakes and also rosy boas this year, but no kings or rattlers. So it seems that an atrox is quite rare there.

Robert
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Fundad
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Re: Range of crotalus atrox and scutulatus

Post by Fundad »

I have personally seen one in the park..

Fundad
RobertH
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

I think we might be talking about different "parks" here. I pm'd you. Robert
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Re: Range of crotalus atrox and scutulatus

Post by hellihooks »

You guys saw the df ruber Tamara posted from AB, right? (Railroad post) Could they be getting confused with Atrox, in that area? jim

Anyone else remember posts about rubers from that area, as possible helli/speck/ruber (some combo) hybrids?
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rpecora
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Re: Range of crotalus atrox and scutulatus

Post by rpecora »

I've seen atrox in southern JTNP, and as far west as the city of Indio. The Chuckwalla's and the Orocopia's also of course as well as Cibola. I'm sure that's no surprise though.

I've only ever seen one scute in JT City about 13 years ago actually thought it was an atrox at the time as I had never seen a scute up to that point. Surprisingly I have yet to see another scute anywhere near there. Very speck heavy in that whole upper desert region.
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Could they be getting confused with Atrox, in that area? jim
Jim, I looked at the picture Tamara Saurus posted and, well, it looks like it may also be atrox. I know she said it's ruber based on range. But as this discussion shows, we can't go by range in the end, at least not if it's a close call (AB is certainly not far from and, as far as I know, partly within atrox range).

In any event, I haven't heard anyone suggest (yet) that the snake I posted is a ruber. It certainly doesn't look like a ruber to me. But I am not an expert. For what it's worth, the story that comes with the picture describes one pissed off snake that was in the middle of the path when encountered. Also doesn't sound like ruber, but more like atrox (or scute).

Two more questions:

1. Is anyone able to make out the intraocular scales on the picture I posted?

2. Is it fairly common for atrox to have irregular tail rings like the one in the picture?

Thanks,

Robert
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Norman D
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Re: Range of crotalus atrox and scutulatus

Post by Norman D »

Nice Atrox Fundad
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Re: Range of crotalus atrox and scutulatus

Post by Fieldnotes »

I have not heard of atrox from the North Slope of San Jacinto Mountain? However, I do know of snakes having been found as far north as Palm Springs, Cathedral City, and Coachella Valley Preserve.

Scutes don’t occur in Coachella Valley. However beyond the Coachella Valley, there are unconfirmed sightings of scutes on Ogilby Road east of Algodones dunes, Imperial County. However, without some type of evidence, one must think that those Ogilby snakes are probably just mis-ID’ed atrox.
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Re: Range of crotalus atrox and scutulatus

Post by VICtort »

Regarding how far one may find C. atrox to the west...we have them here in the Imperial Valley, I have personally seen several specimens near Hotville/Heber Dunes, and a reliable source tells me he found a road kill C. atrox on Hwy 8 where it crosses over the New River.

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Re: Range of crotalus atrox and scutulatus

Post by rosy-man »

there in seeley also and i suspect them close too the prision on dunaway rd atrox that is
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Re: Range of crotalus atrox and scutulatus

Post by Correcamino »

Robert,

Your snake is most definitely an atrox.
Personally, I am not so certain atrox and ruber are really different species. There are too many snakes that are intermediate in appearance (Brians photo is a perfect example) in that area, many of these "atrox" happen to be identical with ruber "lucasensis" in Southern Baja, and yet very similar to east Texas atrox also. The few scalation differences are not really enough to give merit. THe only DNA sequncing that was done was by Castoe (2006) but the snakes sampled were fron Baja and the corresponding atrox population directly across the gulf in Sonora. Atrox is the mother of ruber, and it would stand to reason that given enough time the snakes from those two spots would come back different as they have been separated by the gulf. However, it doesn't address the snakes in Socal where I think it is quite possible there is either gene exchange between the species, or it is just a gradient of one species from desert to coast. I have been trying to find someone who wants to do some DNA on snakes from accross southern California, but so far no bites, atrox and ruber just aren't "cool", lol. I would be happy to get as many samples as possible from across the area.

Tamara's photo is a "desert phase" ruber (If ya had to pick one or the other, lol).

Rich
RobertH
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Rich,

Thanks a lot, that's very interesting information. I had no idea that the taxonomy for c. atrox may be unclear. Fascinating and something I would certainly be interested in learning more about.

For now, however, I would simply like to figure out what to do with this "find" - assuming for now that we are simply dealing with c. atrox. I had hoped that someone might know whether c. atrox has been recorded as far West as the place where the snake in question was found. Fieldnotes, for one, has told me by pm that c. atrox was supposedly seen by others there. But that's of course different from a confirmed, documented and vouchered sighting.

So, it seems like I'll have to either research the issue myself using other databases (such as those Fundad sent me links for) or find a crotalus authority who knows the answer off the bat. The latter would obviously much less work for me. So if anyone knows a crote herpetologist who may know the answer, please let me know.

Thanks,

Robert
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Re: Range of crotalus atrox and scutulatus

Post by hellihooks »

I too, found the Ruber/Atrox relationship possibilities intriguing. Interesting to note, that temperament, as a secondary or ancillary characteristic, could be so different... Ruber... notoriously mild-mannered, Atrox... notoriously 'mean'.
Robert... pm sent. jim
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Re: Range of crotalus atrox and scutulatus

Post by rpecora »

So where was the snake in question found?
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Re: Range of crotalus atrox and scutulatus

Post by hellihooks »

While locality info that specific might be OK in the case of range extensions discussions, it is, in fact, just the sort of thing that the Member's only forum was envisioned for. :thumb: jim
RobertH
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Hence I pm'd Mike the location. :thumb:
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Biker Dave
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Re: Range of crotalus atrox and scutulatus

Post by Biker Dave »

Hey All

Here is the link to Kris Haas' explanation of atrox vs scutulatus with photos.

http://www.azreptiles.com/forums/showth ... us-Defined


Dave
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Re: Range of crotalus atrox and scutulatus

Post by hellihooks »

RobertH wrote:Hence I pm'd Mike the location. :thumb:
Yeah... HENCE! :lol: :lol: (Legally Blonde???)
Actually... I was thinking bout starting a "Range Extension' thread on the MOF... where discussions like this can be carried on more freely... I saw a helli today where they are only VERY Rarely seen, as far as I know. I will share... but only over there... cyaaa (there) :D jim
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Re: Range of crotalus atrox and scutulatus

Post by RobertH »

Mystery solved.

This is the answer I received in reply to my e-mail to the person who encountered the snake in question:

"OOPS. You caught me in a bit of a lie. We did not get a photo of the rattler we ran across on the trail that day, so I bought a photo of a “rattle snake” from a photo service. I am going to have to add a disclaimer to the photo… though it has been there since 2005 without a soul noticing my error. Until an actual Herpetologist found my site. Busted."

Oh well ... :lol:

Robert
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Re: Range of crotalus atrox and scutulatus

Post by hellihooks »

WHAT.... :shock: You can't believe everything you see online??? Who'd a thunk it... :crazyeyes: :lol: :lol: :lol: jim
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Biker Dave
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Re: Range of crotalus atrox and scutulatus

Post by Biker Dave »

I say we hack into that guys system, steal all of his emails and post them publicly on wikileaks...
Oh wait.... we're HERPERS not HACKERS....


:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
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