A Blacktailed Rattlesnake was seen on a late-night hike near Phoenix, Arizona. These snakes are found in any of the regional parks around Phoenix and Tucson. Interestingly, they are missing, however, from the mountains of central Phoenix, with no records that indicate they were ever there.
The most dreaded snake in the West? Likely. For good reason? Not really.
This one is typical for Maricopa County, Arizona. Some may have a green hue, but most are a muted brown or tan. They tend to have a more “clean” look than the more familiar Western Diamondback Rattlesnake, showing less speckling and a tendency to have each scale be its own color.
Mojave Rattlesnakes are common in areas of relatively flat sandy desert scrub and grasslands. Despite their behavior not being meaningfully different than other rattlesnake species, they are often attributed with fanciful abilities and aggressive traits. When someone tells a tall tale that they were chased on horseback for miles or a snake popped a truck tire, it’s usually about these … whether or not this species actually even lives in the area the story occurred is another story.
Their venom, too, is largely a matter of American folklore. It is highly toxic, often involving neurotoxins and a mix of other fun stuff. But it’s highly variable based on region and other factors. A bite from a Mojave Rattlesnake is of course serious business requiring immediate emergency care, but the rumors about not having antivenom or a sure death within minutes are made up.
1. Minton, S. A., & Weinstein, S. A. (1986). Geographic and ontogenic variation in venom of the western diamondback rattlesnake (Crotalus atrox). Toxicon, 24(1), 71–80. https://doi.org/10.1016/0041-0101(86)90167-4
2. Peterson, M. E. (2006). Snake bite: Pit vipers. Clinical Techniques in Small Animal Practice, 21(4), 174–182. https://doi.org/10.1053/j.ctsap.2006.09.004
3. Glenn, J. L., Straight, R. C., Wolfe, M. C., & Hardy, D. L. (1983). Geographical variation in Crotalus scutulatus scutulatus (Mojave rattlesnake) venom properties. Toxicon, 21(1), 119–128. https://doi.org/10.1016/0041-0101(83)90055-7
4. Hardy, D. L. (1983). Envenomation by the Mojave rattlesnake (Crotalus scutulatus scutulatus) in southern Arizona, USA. Toxicon, 21(1), 123–129. https://doi.org/10.1016/0041-0101(83)90054-5
5. Sánchez, E. E., Galán, J. A., Powell, R. L., Reyes, S. R., Soto, J. G., Russell, W. K., … & Pérez, J. C. (2005). Disintegrin, hemorrhagic, and proteolytic activities of Mohave rattlesnake (Crotalus scutulatus scutulatus) venoms lacking Mojave toxin. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 140(2), 221–230. https://doi.org/10.1016/j.cca.2005.05.020
6. Holstege, C. P., Miller, M. B., Wermuth, M., Furbee, R., & Kirk, M. A. (1997). Crotalid snake envenomation. Critical Care Clinics, 13(4), 889–912. https://doi.org/10.1016/S0749-0704(05)70373-0
7. Cardwell, M. D., Massey, D. J., & Smelski, G. (2022). Mohave Rattlesnake (Crotalus scutulatus) Identification Revisited. Wilderness & Environmental Medicine, 33(2), 234–241. https://doi.org/10.1016/j.wem.2022.01.003
8. Strickland, J. (2018). Evolution and Distribution of Phenotypic Diversity in the Venom of Mojave Rattlesnakes (Crotalus scutulatus). [Doctoral dissertation, University of Central Florida]. https://stars.library.ucf.edu/etd/6054/
9. Rael, E. D., Lieb, C. S., & Maddux, N. (1993). Hemorrhagic and Mojave toxins in the venoms of the offspring of two Mojave rattlesnakes. Journal of Comparative Physiology B. PDF via Academia.edu
10. Aird, S. D., Thirkhill, L. J., Seebart, C. S., & Kaiser, I. I. (1989). Venoms and morphology of western diamondback/Mojave rattlesnake hybrids. Journal of Herpetology, 23(2), 85–90. https://www.jstor.org/stable/1564018
One of several Bamboo Vipers found on steep hillsides in Karnataka, India, a couple of years back.
A large Regal Ringnecked Snake greeted me in my driveway as I headed out for the night to look for snakes. Ironically, this was the species I was hoping to see when I set out. This one was about 20″ long, which is large for a ringneck, though not so much so in Arizona. I got some photos and let it go on its way.
A Blacktailed Rattlesnake from southeastern Arizona. They are large, common rattlesnakes in the mountainous regions of much of the state, where they are often misidentified over generations as Mojave Rattlesnakes due to a misunderstanding of the color green in rattlesnakes.
A Southwestern Speckled Rattlesnake making it difficult to tell where snake ends and rock begins.
An Arizona Black Rattlesnake resting in partial cover after an exceptionally rainy few days. In this area, along the eastern edge of their range in Arizona, the species can look a bit different. The light bands on this individual, for instance, are wide, in some cases as wide as the darker blotches they surround, and the snake may never darken (much). This is typical for the area, though, as most of the photos you may see of Arizona Black Rattlesnakes online or in field guides are from a handful of more central locations.
A good-sized Costa Rican Coralsnake we saw in the grass on a family vacation. These are very different than the coralsnakes we have back in Arizona. It’s much larger and willing to strike, which it did repeatedly. These snakes are a handful to get photos of, but we managed and let it disappear back into the forest.
A Southwestern Speckled Rattlesnake resting in the shade outside its summer aestivation den. It’s one of a handful that gather here each year to hide from the heat and gestate.
A young Mojave Rattlesnake at rest, lifted just off the surface of the warm sand to get a little air flow. Thermoregulation is far from just “sunning” – much of the activity of reptiles in the desert during the summer is about getting cooler, rather than warmer.
