Question about the Mojave rattlesnake and W. Diamondback

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James1617
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Question about the Mojave rattlesnake and W. Diamondback

Post by James1617 »

I was just wondering if anyone else had any trouble learning how to tell a W. Diamondback from a Mojave. For me they just look so close sometimes. The only way I know of and it doesn't really help much is the bigger white bands on the tail of the Mojave. (Just something I was told)<

Can anyone give me some tips on how to tell them apart?
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Daryl Eby
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by Daryl Eby »

There are lots of subtle differences, but almost all (including the width of the banding) are highly variable. Nine times out of ten, I just know by gestalt. When uncertain, I rely on the head scales. Unfortunately, my eyesight is not always good enough to judge this from a safe distance. So, I just zoom in on the head, snap a photo, then enlarge it on my computer for a 100% certain ID.
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reptilist
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by reptilist »

The WDB has little granular scales between the supraoculars, whereas the scut's have 2-3 larger scales in the same location.
Also, although it may not be universal, the scut's supraoculars outside edge is light colored, whereas the wdb is the same as the scale. (Scuts appear to have white eyebrows.)
Scuts tend to have a more distinct diamond pattern, compared to a generally faded wdb.
If I remember right, the white line on each side of a scut's face extends past the end of the mouth, but the wdb does not..... But I never go by that myself, I might even have it backwards.
hellihooks
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by hellihooks »

Way,WAY back in the day... scutes were called 'plate rattlers' for the 'plates' tween the supraoculars, rather than the granular scales.
everything else is pattern/color and subject to variability... scales are definitive. :thumb: jim
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reptilist
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by reptilist »

Not the best pictures in the world.....

C. scutulatus:

Image

C. atrox:

Image
bgorum
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by bgorum »

I’m with Daryl on this one. There is a certain difference in gestalt between the two, (which does you no good at all if you haven’t seen a bunch of both). The scale characters, combined with the placement of the eye stripe, and the narrower black bands on the tail, all taken together are ideal for positive id. For me though mojaves have a certain prairie rattlesnake like appearance, (maybe its just because of the often greenish color and the eye stripe), that diamondbacks lack. In fact the rattlesnake museum here in Albuquerque has an atrox/viridis hybrid that to my eyes looks an awful lot like a mojave.
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by hellihooks »

man.... I passed through Albuquerque on my X-country herping trip... wish I'd known there was a Rattlesnake Museum there... :roll:
I liked Albuquerque a LOT!! :D jim
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Bryan Hamilton
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by Bryan Hamilton »

It took me a while to tell them apart too.

I usually rely on the tail banding. In atrox, the black and white bands are approximately equal in width. In scutulatus the white bands are much wider than the black. I definitely rely on gestalt when I first see them, head size is narrower in scutulatus, color is a little different, texture seems different.

I've never thought of scutulatus as viridis like bgorum. It's an interesting comparison.

Its easy in areas where they are not sympatric.
Bob McKeever
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by Bob McKeever »

Like Bryan, I key first on the tail banding & color. Width of the darker bands in relation to the lighter bands has been mentioned here a few times already & this works pretty well for some snakes. For those scutulatus with tail bands whose widths approximate an atrox I find that the "quality" of the lighter bands can sometimes be relied on. Atrox nearly always has bold whitish bands, if not white, while scutualtus has a less distinct quality to the lighter bands. They are often "dusty" looking, even grayish or light greenish. For those that I'm still not sure of from a distance I key on the ocular stripes & have found this character reliable. In scutulatus the posterior light stripe does not often cross the mouth line, rather, when it reaches the mouth it turns posteriorly & extends onto the rear of the jaw. In atrox the posterior light ocular line angles downward to intersect the mouth & does not pass posteriorly onto the jaw. If there's still doubt, I usually make sure I get a quality photo of the dorsal surface of the head in order to check the scales that are the key.

If none of this works sometimes they fess up if proper interview techniques are used.
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by hellihooks »

Scutes will sometimes sit through such an interview... Atrox rarely do... :crazyeyes: Which is to say that sometimes 'disposition' can be considered a confirming secondary-identification clue.... does it ACT like am Atrox or scute? :) jim
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Daryl Eby
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by Daryl Eby »

hellihooks wrote:Scutes will sometimes sit through such an interview... Atrox rarely do... :crazyeyes: Which is to say that sometimes 'disposition' can be considered a confirming secondary-identification clue.... does it ACT like am Atrox or scute? :) jim
I've met several Scutes that hold their tails in a corkscrew coil and hiss instead of rattle. I've never seen that in any other Crote.
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by hellihooks »

Daryl Eby wrote:
hellihooks wrote:Scutes will sometimes sit through such an interview... Atrox rarely do... :crazyeyes: Which is to say that sometimes 'disposition' can be considered a confirming secondary-identification clue.... does it ACT like am Atrox or scute? :) jim
I've met several Scutes that hold their tails in a corkscrew coil and hiss instead of rattle. I've never seen that in any other Crote.
Hissy Fit? :lol: :lol: I've seen Ruber get 'hissy', but have yet to see what you describe in Ca. scutes... maybe it's a ' locality deal' like slang... Yaaaalllll have a good unnnn now, ya hear. :lol: :lol: jim
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Daryl Eby
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by Daryl Eby »

I've seen the twisted tail hissing Scutes in South Brewster and North Presidio Counties (about 100 miles apart). The tail thing is really weird. Almost like a deformation. It is even twisted/coiled as they crawl. I've never heard one with a twisted tail rattle effectively. Perhaps they are unable ... hence their propensity to hiss almost a loudly as bullsnakes.
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by herpseeker1978 »

Daryl Eby wrote:
hellihooks wrote:Scutes will sometimes sit through such an interview... Atrox rarely do... :crazyeyes: Which is to say that sometimes 'disposition' can be considered a confirming secondary-identification clue.... does it ACT like am Atrox or scute? :) jim
I've met several Scutes that hold their tails in a corkscrew coil and hiss instead of rattle. I've never seen that in any other Crote.
I met a viridis that hissed at me instead of rattling, but did rattle later in the visit.

Josh
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The Jake-Man
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by The Jake-Man »

horridus does that occasionally too. I've encountered one snake that hissed, but didn't rattle, and another that struck my leg without any rattle or hiss. I was walking through tall ferns and stepped about 6 inches from it's head without knowing it.
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by hellihooks »

Helleri often strike first, rattle second... :D I don't want to get into the 'nastiest' crote debate (none are nasty if you leave them alone) but it has to be allowed that some species are more (to borrow J. Lemm's characterization) 'irascible' than other species.
Atrox are usually quite 'irascible' (as are helli) Scutes... perhaps less so. For those experienced enough for 'gestalt' id's between the two, I'd guess 'temperament' plays a part. jim
chad ks
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by chad ks »

After you've found a bunch of them in places where they do not overlap and where there's no question of the identity, you'll be much better skilled at identifying them when they are found in overlap zones and even between hybrids between them and other Crotes such as viridis.
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jonathan
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Re: Question about the Mojave rattlesnake and W. Diamondback

Post by jonathan »

Bob McKeever wrote:If none of this works sometimes they fess up if proper interview techniques are used.
I dispute that a little - usually the crot just holds out until it can't anymore and then it just tells the interviewer whatever they want to hear, usually self-identifying to give them the lifer/locality they were looking for. :thumb:
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