A Guide to the Amphibians
and Reptiles of California

Differences Between

Western Diamond-backed Rattlesnake -
Crotalus atrox
&
Northern Mohave Rattlesnake -
Crotalus scutulatus scutulatus

Click on a picture for a larger view

Northern Mohave Rattlesnake - Crotalus scutulatus scutulatus

Western Diamond-backed Rattlesnake Habitat range map

Western Diamond-backed Rattlesnake - Crotalus atrox

The field marks below can help differentiate these two similar species of rattlesnake where their ranges overlap in California. Since both of these species are dangerously venomous, I do not advise handling a snake. Instead, use binoculars, or take a picture with a telephoto lens and then enlarge the picture, to see the field marks. This will be the only way to observe the supraocular scales.

LIght Stripe Behind the Eye
Northern Mohave Rattlesnake - Crotalus scutulatus scutulatus		Western Diamond-backed Rattlesnake - Crotalus atrox
A light stripe extends from behind the eye diagonally to beyond the end of the jaw.		A light stripe extends from behind the eye diagonally to the upper lip in front of the end of the jaw.





Number of Scales Between the Supraoculars
(The supraoculars are the large scales directly above each eye.)
Northern Mohave Rattlesnake - Crotalus scutulatus scutulatus		Western Diamond-backed Rattlesnake - Crotalus atrox
There are 2 large scales between the supraoculars		There are 4 or more small scales between supraoculars.




Width of the Rings on the Tail Color Next to the Rattle
Northern Mohave Rattlesnake - Crotalus scutulatus scutulatus		Western Diamond-backed Rattlesnake - Crotalus atrox
The black rings are narrower than the light rings, and often offset.		Broad black and white rings are fairly equal in width.
The color of the ring closest to the rattle is usually White		The color of the ring closest to the rattle is usually Black








Rattlesnake References Robert Powell, Joseph T. Collins, and Errol D. Hooper, Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. © 1998 by the University Press of Kansas. Chester J. Stojanovich and Margaret A. Parsons. Snakes: Pictorial Key to Venomous Species in United States Klauber, Laurence M. Rattlesnakes. University of California Press. (Abridged from the 1956 two volume Rattlesnakes: Their Habits, Life Histories, and Influence on Mankind.) University of California Press, 1982. Stebbins, Robert C., and McGinnis, Samuel M. Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012. Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972. Hubbs, Brian R., & Brendan O'Connor. A Guide to the Rattlesnakes and other Venomous Serpents of the United States. Tricolor Books, 2011. Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Snakes of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.