Range in California: Red
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Venomous and Potentially Dangerous!
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Adult, Cochise County, Arizona
Listen to this snake
rattling and hissing.
More Rattlesnake sounds and videos |
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Adult, Riverside County
© Patrick Briggs |
Top of head showing several small scales between intraoculars. Compare with the Northern Mohave Rattlesnake.
© Patrick Briggs |
Adult, Riverside County. Note that the rear light strip does not extend back to the corner of the mouth. © Patrick Briggs |
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Adult, Santa Cruz County, Arizona |
Juvenile eating a rodent on a road at night, Hidalgo County, New Mexico. |
Adult,Yavapai County, Arizona |
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Habitat, Riverside County
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Habitat, Imperial County |
Habitat, Riverside County |
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California National Wildlife Refuge warning sign.
Click the picture to see more
rattlesnake signs. |
Tail |
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Rattlesnakes are important members of the natural community. They will not attack, but if disturbed or cornered, they will defend themselves. Reasonable watchfulness should be sufficient to avoid snakebite. Give them distance and respect.
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| Short Video |
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Several views of a Western Diamond-backed Rattlesnake rattling and
taking a defensive pose with head and tail elevated, then crawling away. |
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Description |
| Venomous |
| The venom of this snake is potentially dangerous to humans. |
| Size |
| Adults 30-90 inches (76-229 cm). The average size of snakes most encountered is 1 to 4 feet in length. |
| Appearance |
The largest rattlesnake in California, and in the West. Heavy-bodied, dangerously venomous, with a thin neck and a large triangular head. Pupils are elliptical. Scales are keeled. Sometimes 3, but usually 4 or more small scales occur on top of the head between the supraocular scales. (The Northern Mojave Rattlesnake has 2 large scales between the supraocular scales.)
The ground color and the intensity of the pattern are variable, often matching the habitat; grey, brown, olive, tan, or yellowish. Diamond-shaped blotches on the back are brown or black, with light edges. Broad black and white rings, fairly equal in width, circle a thick tail with a rattle, consisting of loose interlocking segments, at the end. A new rattle segment is added each time the skin is shed. Newly-hatched snakes do not have a rattle - just a single button which does not make a sound. A light stripe extends from behind the eye diagonally to the upper lip in front of the corner of the mouth crossing over the lip. (The posterior light stripe of the Northern Mohave Rattlesnake extends back beyond the corner of the mouth and does not cross the lip.)
Similar to and easily confused with the Northern Mohave Rattlesnake, though there is little range overlap in California. Also similar to and easily confused with the Red Diamond Rattlesnake, but in California the ranges of these two snakes barely meet, and the Red Diamond Rattlesnake is typically light reddish brown or red in color.
A pit viper with pits on the sides of the head which sense heat. These heat sensors help the snake to locate prey by their warmth. Long, hollow, movable fangs connected to venom glands inject a very toxic venom which quickly immobilize the prey. The snake can control the amount of venom injected and the fangs are replaced if broken. Bites on humans are potentially deadly without immediate medical treatment. Even a dead snake can bite and inject venom if the jaws reflexively open when they are touched. |
| Behavior |
Primarily nocturnal during periods of excessive daytime heat, but also active during daylight when the temperature is more moderate. Not active during cooler periods in Winter.
An ambush hunter, it typically sits near the trail of a mammal, waiting for it to pass by, then strikes at and releases the prey. The snake then follows the trail of the envenomated animal and swallows it whole.
When alarmed, a rattlesnake shakes its tail back and forth. The movement rubs the rattle segments together producing a buzzing sound which serves as a warning. When disturbed, in self-defense Western Diamond-backs will often aggressively hold their ground, raising the head high in a striking coil with the tail elevated and rattling, and hissing loudly. Juveniles are born with only a silent button at the end of the tail. |
| Diet |
Eats small mammals, birds, lizards. Juveniles sometimes eat large insects and frogs.
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| Reproduction |
| Live-bearing. Males engage in ritual combat mostly during the breeding season to defend territory. Necks and forebodies are intertwined, with the stronger snake slamming the smaller one to the ground until the weaker snake leaves the area. |
| Range |
| Found in southeast California in Imperial, Riverside, and San Bernardino Counties. Ranges east to Arkansas and East Texas, and south through Arizona, New Mexico and Oklahoma into Mexico. |
| Habitat |
| Inhabits arid and semiarid areas including mountains, deserts, canyons and rocky vegetated foothills, generally less than 1000 ft. elevation (300 m). |
| Conservation Issues (Conservation Status) |
| None. |
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Taxonomy |
| Family |
Viperidae |
Vipers |
| Genus |
Crotalus |
Rattlesnakes |
Species
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atrox |
Western Diamond-backed Rattlesnake |
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Original Description |
Baird and Girard, 1853 - Cat. N. Amer. Rept., Pt. 1, p. 5
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Crotalus - Greek - krotalon - a rattle - refers to the rattle on the tail
atrox - Latin - atrox dark, fierce, savage - referring to the sometimes savage disposition of this species
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Western Diamondback Rattlesnake
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Related or Similar Neighboring California Snakes |
C. ruber - Red Diamond Rattlesnake
C. s. scutulatus - Northern Mohave Rattlesnake
C. c. laterorepens - Colorado Desert Sidewinder
C. c. cerastes - Mohave Desert Sidewinder
C. m. pyrrhus - Southwestern Speckled Rattlesnake
C. o. helleri - Southern Pacific Rattlesnake
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
Living With Rattlesnakes
Tucson Herpetological Society: Living With Venomous Reptiles pdf
California Department of Fish and Game: Rattlesnakes in California
Rattlesnake Bites
California Poison Control System:
Rattlesnake Bites
University of Arizona:
Rattlesnakes
Justin Schwartz' Rattlesnake Bite Story and Pictures
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.
Behler, John L., & F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.
Bartlett, R.D. , & Alan Tennant. Snakes of North America - Western Region. Gulf Publishing Co., 2000.
Ernst, Carl H., Evelyn M. Ernst, & Robert M. Corker. Snakes of the United States and Canada. Smithsonian Institution Press, 2003.
Wright, Albert Hazen & Anna Allen Wright. Handbook of Snakes of the United States and Canada. Cornell University Press.
Brown, Philip R. A Field Guide to Snakes of California. Gulf Publishing Co., 1997. Ernst, Carl. H. Venomous Reptiles of North America. Smithsonian Institution Press, 1999.
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.
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The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.
This snake is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.
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Organization
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Status Listing
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| U.S. Endangered Species Act (ESA) |
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| California Endangered Species Act (CESA) |
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| California Department of Fish and Game |
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| Bureau of Land Management |
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| USDA Forest Service |
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| Natureserve Global Conservation Status Ranks |
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World Conservation Union - IUCN Red List
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