Wednesday

Mohave Desert Sidewinder (Crotalus cerastes cerastes)

{Click on any image to view full size, then use the back button on your browser to return to this page}
This page last updated on 05/31/2019
EFP-P1000909
(Fig. 01) A 2013 sighting while hiking near the Bowel of Fire
Picture Notes: On 05/30/2019, while driving along Christmas Pass Road down near Laughlin, we spotted two sidewinders in the road. This was the first time Jim Herring had ever encountered a rattlesnake. When we got out to snap some pictures we were amazed at how loud their rattles were when we approached them. The first one we spotted (Fig. 02) slithered off the road and disappeared into a hole that was at the base of a creosote bush. Even though he was out of sight we could still hear his rattle. About 10 minutes later we spotted a second one on the side of the road that appeared kind of fat like he might have recently eaten something (Fig. 04 & 05). He also slithered off the road and hid in a nearby bush (Fig. 06).

(Fig. 02) A 2019 sighting driving on Christmas Pass Road.
(Fig. 03)
(Fig. 04) Our second sighting that same day
(Fig. 05)
(Fig. 06)
Back in May of 2013, while hiking to the Bowl of Fire from the mile 18.2 parking area along Lake Mead’s Northshore Drive, I nearly stepped on this Sidewinder (Figs 01, 07 & 08). From this trailhead you have to walk around the tip of a large hill, known as Hill 651. Just after rounding this hill, hiking in a slightly northeast direction, is where I encountered him. About five month after that while hiking along the Sandy Valley Road near the Ignomar Mine, it was my hiking partner, Grant Brown, that nearly stepped on one (Figs 09-11). I heard a startled hollar and looked to see him take a four foot step backwards in one motion. Right away, I knew it must have been a rattlesnake. Because he offered no movement for quite some time, I thought it might have been dead. However, as I moved some twigs out of the way for a better picture, he stuck his little black tongue out. It's amazing how well these guys can camouflage themselves to blend into the environment.
              
EFP-P1000913
(Fig. 07)
Description: Named for its side-winding locomotion, the Mohave Desert Sidewinder is Nevada’s smallest rattlesnake, reaching up to 31 inches in length. Notice to the right of his head in (Fig. 01), how the rest of its body continues to wrap around the visible coil, covered by the surrounding sand, and completely covering the rattles on his tail. Counting this, I would estimate its length to be about 30 inches, meaning this was a fully grown snake. Primarily inhabiting valleys and alluvial fans a series of backward J or S shapes left in loose soil indicates where one has passed by. As shown in these pictures, when at rest, they partially bury themselves in loose sand or gravel. It is sometimes referred to as the “horned rattler” because of the modified scales above its eyes (Fig. 07). All rattlesnakes in Nevada have facial or loreal pits, heat-sensitive depressions, on either side of the head between the nostril and eye. This can be seen if you click (Fig. 07) to enlarge it to full size. These pits can detect differences in temperatures of less than 0.5° F in nearby objects, thereby allowing them to detect prey, even in complete darkness. In (Fig. 08) you can see where my foot passed within an inch of his head.
                       
EFP-P1000911
(Fig. 08)
There are approximately 52 species of snakes and lizards in the state of Nevada.  Of these, only 12 are considered venomous; only six can be dangerous to people and pets. They are all members of the Viperidae family, the pit vipers, and include the Sidewinder, Mohave Green, Speckled, Western Diamondback and Great Basin rattlesnakes. Encountering them is uncommon because of their body camouflage and secretive nature, which are their first defenses in evading predators. You can consider yourself fortunate if you are lucky enough to see one! Now I've seen four of them.
             
Compared to most non-venomous snakes, rattlesnakes have broad triangular shaped heads that
accommodate the venom glands and muscles controlling them. Pit vipers use fangs to dispense venom, which is a complex toxic compound used both to subdue prey and protect against predators. Having the ability to dispense venom using these fangs can mean life or death for rattlesnakes. When not in use, the fangs are folded against the roof of the mouth, swinging down as the snake lunges forward to strike, releasing its venom through the fang into the prey. Fangs are not permanent; they are periodically replaced. Flexible jaws allow snakes to swallow their prey whole. Rattlesnakes have a triangular head that gives way to a narrow neck, thick body and a tail that is tipped with a series of interlocking segments making up the rattle. Shedding from one to three times a year; every time a snake sheds its skin a new segment is added. However, sometimes rattle segments break off, which is why rattlesnakes cannot be aged by simply counting their rattle segments.  During high summer temperatures in the Mohave Desert, reptiles may estivate underground in order to maintain vital body temperatures.

This species occurs in southeastern California, southern Nevada, southwestern Utah, western Arizona, and southward into northwestern Mexico. The subspecies in Nevada is the Mojave Desert sidewinder (Crotalus cerastes cerastes); other subspecies occur in the Colorado and Sonoran deserts.
                  
EFP-Image00013
(Fig. 09)
EFP-Image00011
(Fig. 10)
EFP-Image00015
(Fig. 11)