Range of crotalus atrox and scutulatus

Dedicated exclusively to field herping.

Moderator: Scott Waters

Post Reply
RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 10:20 am

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

User avatar
Fundad
Posts: 5722
Joined: June 7th, 2010, 6:11 am
Location: Los Angeles County
Contact:

Re: Range of crotalus atrox and scutulatus

Post by Fundad » February 22nd, 2012, 10:37 am

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

User avatar
monklet
Posts: 2648
Joined: June 7th, 2010, 3:44 pm
Location: Ventura, CA
Contact:

Re: Range of crotalus atrox and scutulatus

Post by monklet » February 22nd, 2012, 11:01 am

Brian, are there any WDBs in JT?

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 11:26 am

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

User avatar
Fundad
Posts: 5722
Joined: June 7th, 2010, 6:11 am
Location: Los Angeles County
Contact:

Re: Range of crotalus atrox and scutulatus

Post by Fundad » February 22nd, 2012, 11:30 am

@ Monklet Yes in certain areas...

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

Fundad

User avatar
PNWHerper
Posts: 667
Joined: July 8th, 2011, 1:04 pm
Location: King County, WA

Re: Range of crotalus atrox and scutulatus

Post by PNWHerper » February 22nd, 2012, 11:45 am

Out of curiosity, are there habitat or mico-habitat preferences that are different for the 2 species where their ranges overlap? Or tendencies, even?

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 11:55 am

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?

User avatar
Fundad
Posts: 5722
Joined: June 7th, 2010, 6:11 am
Location: Los Angeles County
Contact:

Re: Range of crotalus atrox and scutulatus

Post by Fundad » February 22nd, 2012, 12:03 pm

Atrox 100 percent

Fundad

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 12:17 pm

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

User avatar
Kent VanSooy
Posts: 1100
Joined: June 7th, 2010, 6:51 am
Location: Oceanside

Re: Range of crotalus atrox and scutulatus

Post by Kent VanSooy » February 22nd, 2012, 12:20 pm

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
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 12:28 pm

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

User avatar
Fundad
Posts: 5722
Joined: June 7th, 2010, 6:11 am
Location: Los Angeles County
Contact:

Re: Range of crotalus atrox and scutulatus

Post by Fundad » February 22nd, 2012, 12:38 pm

Image

From the mid to western c valley area..

Fundad

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 2:49 pm

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

User avatar
Fundad
Posts: 5722
Joined: June 7th, 2010, 6:11 am
Location: Los Angeles County
Contact:

Re: Range of crotalus atrox and scutulatus

Post by Fundad » February 22nd, 2012, 3:16 pm

I have personally seen one in the park..

Fundad

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 3:21 pm

I think we might be talking about different "parks" here. I pm'd you. Robert

hellihooks
Posts: 8025
Joined: June 8th, 2010, 7:12 am
Location: Hesperia, California.
Contact:

Re: Range of crotalus atrox and scutulatus

Post by hellihooks » February 22nd, 2012, 4:17 pm

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?

User avatar
rpecora
Posts: 578
Joined: June 10th, 2010, 3:41 pm

Re: Range of crotalus atrox and scutulatus

Post by rpecora » February 22nd, 2012, 4:53 pm

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.

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 22nd, 2012, 9:21 pm

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

User avatar
Norman D
Posts: 454
Joined: November 4th, 2010, 7:10 am
Location: Sonoran Desert

Re: Range of crotalus atrox and scutulatus

Post by Norman D » February 23rd, 2012, 1:43 am

Nice Atrox Fundad

User avatar
Fieldnotes
Posts: 1470
Joined: June 7th, 2010, 5:12 pm
Location: Orange County, CA
Contact:

Re: Range of crotalus atrox and scutulatus

Post by Fieldnotes » February 23rd, 2012, 2:44 am

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.

VICtort
Posts: 688
Joined: July 2nd, 2010, 5:48 pm
Location: AZ.

Re: Range of crotalus atrox and scutulatus

Post by VICtort » February 23rd, 2012, 8:01 am

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.

Vic

User avatar
rosy-man
Posts: 317
Joined: June 7th, 2010, 8:43 am
Location: East of san diego

Re: Range of crotalus atrox and scutulatus

Post by rosy-man » February 23rd, 2012, 8:33 am

there in seeley also and i suspect them close too the prision on dunaway rd atrox that is

User avatar
Correcamino
Posts: 444
Joined: June 10th, 2010, 11:50 am

Re: Range of crotalus atrox and scutulatus

Post by Correcamino » February 23rd, 2012, 8:38 am

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
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 23rd, 2012, 10:13 pm

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

hellihooks
Posts: 8025
Joined: June 8th, 2010, 7:12 am
Location: Hesperia, California.
Contact:

Re: Range of crotalus atrox and scutulatus

Post by hellihooks » February 24th, 2012, 8:10 am

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

User avatar
rpecora
Posts: 578
Joined: June 10th, 2010, 3:41 pm

Re: Range of crotalus atrox and scutulatus

Post by rpecora » February 24th, 2012, 10:36 am

So where was the snake in question found?

hellihooks
Posts: 8025
Joined: June 8th, 2010, 7:12 am
Location: Hesperia, California.
Contact:

Re: Range of crotalus atrox and scutulatus

Post by hellihooks » February 25th, 2012, 7:15 am

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
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 25th, 2012, 8:06 am

Hence I pm'd Mike the location. :thumb:

User avatar
Biker Dave
Posts: 2854
Joined: June 10th, 2010, 6:56 pm
Location: Wittmann,AZ

Re: Range of crotalus atrox and scutulatus

Post by Biker Dave » February 25th, 2012, 8:09 am

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

hellihooks
Posts: 8025
Joined: June 8th, 2010, 7:12 am
Location: Hesperia, California.
Contact:

Re: Range of crotalus atrox and scutulatus

Post by hellihooks » February 25th, 2012, 3:01 pm

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

RobertH
Posts: 1834
Joined: June 7th, 2010, 8:38 pm
Location: Los Angeles

Re: Range of crotalus atrox and scutulatus

Post by RobertH » February 28th, 2012, 8:33 pm

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

hellihooks
Posts: 8025
Joined: June 8th, 2010, 7:12 am
Location: Hesperia, California.
Contact:

Re: Range of crotalus atrox and scutulatus

Post by hellihooks » February 28th, 2012, 9:08 pm

WHAT.... :shock: You can't believe everything you see online??? Who'd a thunk it... :crazyeyes: :lol: :lol: :lol: jim

User avatar
Biker Dave
Posts: 2854
Joined: June 10th, 2010, 6:56 pm
Location: Wittmann,AZ

Re: Range of crotalus atrox and scutulatus

Post by Biker Dave » February 29th, 2012, 6:32 pm

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:

Post Reply