Range in California: Red
iPhone App
Electronic Field Guide to the
Reptiles and Amphibians of
Southern California
Available Now at the
iTunes App Store. |
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Venomous and Potentially Dangerous!
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Adult, coastal San Diego County |
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Adult, San Diego County desert |
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| Adult, Imperial County desert, found in ambush mode coiled up in the sand between rocks at night. |
Adult, Imperial County desert |
Adult, San Diego County desert |
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Adult, crossing a popular hiking trail in coastal San Diego County in the middle of the afternoon, managing
to avoid observation by all visitors except myself. You can see the tracks it made in the sand on the right.
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3 adults found under the same rock in early March in San Diego County.
© Stuart Young |
Adult, San Diego County. Specimen courtesy of Tim Burkhardt |
Juvenile, desert slope of San Diego County mountains |
Adult, crawling on boulder at night,
San Diego County desert |
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Adult, coastal Riverside County
© 2005 Jeremiah Easter |
Adult, San Diego County
© Jason Jones |
Adult, coastal Riverside County
© Brad Alexander |
Adult, Riverside County
© Michael Clarkson |
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| Adult, San Diego County desert. © Lori Paul |
Adult, San Diego County
© Ryan Shatto |
Adult, San Diego County
© Ryan Shatto |
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| Adult, foothills of Santa Ana Mountains, Orange County. © Jay Selman |
Adult, Riverside County © John Worden |
Juvenile, Riverside County © Tom Harkins |
Adult, San Diego County
© John Stoklosa |
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| Head of adult |
Juvenile head, San Diego County
© Patrick Briggs |
Tail with rattle |
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| Breeding |
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| Adults mating in San Diego County © Shelly Hancock |
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| Habitat |
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| Habitat, San Diego County desert canyon |
Habitat, rocky hillside, coastal
Riverside County |
Habitat, Riverside County -
riparian desert foothills |
Habitat, San Diego County desert oasis |
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Habitat, desert slope of
San Diego County mountains |
Habitat, hillside coastal chaparral,
San Diego County |
Habitat, riparian canyon
coastal San Diego County |
Coastal habitat, San Diego County |
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Habitat, desert boulder piles
Imperial County,
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Habitat, rocky hillside,
Riverside County © Brian Hinds |
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| Short Videos and Sound |
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| A large old Red Diamond Rattlesnake rattles on top of a boulder in coastal San Diego County. |
A close view of a rattling Red Diamond Rattlesnake's tail. |
A large adult Red Diamond Rattlesnake crawls up some large boulders at the edge of a desert wash in San Diego County. After trying to climb up past the top of the boulder, it crawled back down. Despite the bright lights, it did not appear to notice me and continued its nocturnal wandering. |
A Red Diamond Rattlesnake crawls across the hot sand at mid day in San Diego County, then takes shelter between some rocks. |
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| A Red Diamond Rattlesnake found on a desert road at night. |
Listen to a rattlesnake rattling.
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California State Park warning sign.
Click the picture to see
more rattlesnake signs. |
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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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Rattlesnake bites can be extremely dangerous, but unlike the popular depiction of rattlesnakes in the media and folklore, they should not be considered vicious and aggressive. The display we often see in pictures and film, with the body partly coiled, the tail rattling loudly, and the head up ready to strike, is a defensive stance, used when they feel that crawling away to safety is a danger to them. This display is a warning not to come any closer or they will strike. When given some space and the chance to escape to a safe place, they will do so quickly rather than attack.
Rattlesnakes often use their cryptic color and pattern to blend into their surroundings to hide from other animals that could threaten them. They lie still to avoid detection and do not rattle, because that would give away their location. At other times they rattle readily, sometimes from a good distance, to warn potential enemies of their presence. In both cases they are doing everything they can to avoid confrontation and to avoid striking and biting and using up their valuable supply of venom. |
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Description |
Venomous |
| The venom of this snake is potentially dangerous to humans. |
| Size |
Adults are 30 - 65 inches in length ( 76 - 165 cm) typically 2 - 4.5 feet long. Young about 12 inches long.
(Unlike most snake species, males of this species tend to be larger in body length than females.) |
| Appearance |
A heavy-bodied, venomous pit viper, with a thin neck and a large triangular head. Pupils are elliptical. Scales are keeled.
Variable in ground color; pink, reddish-tan, reddish-brown or brick red. Diamond-shaped blotches, usually with light edges, mark the back. Juveniles are duller in coloring than adults. The underside is usually dull yellow and unmarked. Black and white rings surround a thick tail. A rattle, consisting of loose interlocking segments, usually occurs at the end of the tail. A new rattle segment is added each time the skin is shed. Newborn snakes do not have a rattle - just a single button which does not make a sound.
Similar to and easily confused with the Western Diamond-backed Rattlesnake, but in California the ranges of these two snakes barely meet, and the Western Diamond-backed Rattlesnake in Calfornia does not typically show a red color phase.
Heat sensing pits on the sides of the head 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 prey. The snake can control the amount of venom injected and the fangs are replaced if broken. Bites on humans are potentially dangerous 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 and crepuscular during periods of excessive daytime heat, but also active during daylight when the temperature is more moderate or when in the comparatively cooler shaded areas of boulder fields. Not active during cooler periods in Winter. Terrestrial, but may partially climb shrubs or trees.
Prey is found when actively moving, or by ambush, where the snake waits near lizard or rodent trails, striking at and releasing passing 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. Juveniles are born with only a silent button at the end of the tail. |
| Diet |
Eats small mammals, including ground squirrels, wood rats, and rabbits, lizards, and birds.
(Adult California Ground Squirrels are immune to rattlesnake venom and will intensely confront any snake they feel to be a threat.)
Dugan and Hayes, 2012, found that this species specializes on mammalian prey, with terrestrial rodents the primary prey source. Wood rats were the most abundant prey species, followed by kangaroo rats, pocket mice, and deer mice. Coastal populations average longer in body size and eat a higher proportion of larger rodents than snakes from desert populations.
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| Reproduction |
Breeding occurs in the spring. Male rattlesnakes search extensively for females during the mating season while females do not actively search for males. Male to male combat occurs.
Live-bearing; young are born July - September. |
| Range |
| Found in southwestern California, from the Morongo Valley west to the coast and south along the peninsular ranges to mid Baja California. |
| Habitat |
| Inhabits arid scrub, coastal chaparral, oak and pine woodlands, rocky grassland, cultivated areas. On the desert slopes of the mountains, it ranges into rocky desert flats. |
| Taxonomic Notes |
| Previously recognized as a subspecies of Crotalus ruber: Crotalus ruber ruber. Some taxonomists regard this snake as a subspecies of Crotalus exsul labelling it Crotalus exsul ruber. |
| Conservation Issues (Conservation Status) |
| A CA Dept. of Fish and Game California Species of Special Concern, due to habitat loss in the coastal region. |
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Taxonomy |
| Family |
Viperidae |
Vipers |
| Genus |
Crotalus |
Rattlesnakes |
Species
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ruber |
Red Diamond Rattlesnake |
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Original Description |
Crotalus ruber - Cope, 1892 - Proc. U.S. Natl. Mus., Vol. 14, p. 690
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
ruber - Latin - red - referring to the reddish color of dorsum Cope, 1892
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Crotalus exsul
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Related or Similar California Snakes |
C. atrox - Western Diamond-backed Rattlesnake
C. s. scutulatus - Northern Mohave Rattlesnake
C. c. laterorepens - Colorado 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
University of California: Rattlesnakes Management Guide
Florida Museum of Natural History: How to Get Along with Snakes
Southwestern Field Herping Associates: Venomous Snake Safety
Rattlesnake Bites
California Poison Control System (search for "rattlesnake bite")
University of Arizona:
Rattlesnakes
Justin Schwartz' Rattlesnake Bite Story and Pictures
Sean Bush MD: Venom ER - When snakes strike!
eNature - How to Avoid Snakebites and How to Treat One
When a Pet Gets Snake Bitten: The amazing story of Andy Cat, a very lucky cat who was bitten by a rattlesnake and survived, thanks to the smart actions of its owners.
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.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.
Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.
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.
Bartlett, R. D. & Alan Tennant. Snakes of North America - Western Region. Gulf Publishing Co., 2000.
Brown, Philip R. A Field Guide to Snakes of California. Gulf Publishing Co., 1997.
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.
Ernst, Carl. H. Venomous Reptiles of North America. Smithsonian Institution Press, 1999.
Hayes, William K., Kent R. Beaman, Michael D. Cardwell, and Sean P. Bush, editors. The Biology of Rattlesnakes. Loma Linda University Press, 2009.
Hubbs, Brian R., & Brendan O'Connor. A Guide to the Rattlesnakes and other Venomous Serpents of the United States. Tricolor Books, 2011.
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.
Rubio, Manny. Rattlesnake - Portrait of a Predator. Smithsonian Institution Press, 1998.
Walls, Jerry G. Rattlesnakes: Their Natural History and Care. T. F. H. Publications, Inc., 1996.
Eric A. Dugan and William K. Hayes. Diet and Feeding Ecology of the Red Diamond Rattlesnake, Crotalus Ruber (Serpentes: Viperidae)
Herpetologica, 68(2), 2012, 203–217 E 2012 by The Herpetologists’ League, Inc.
Eric A. Dugan, Alex Figueroa, and William K. Hayes. Home Range Size, Movements, and Mating Phenology of Sympatric Red Diamond (Crotalus ruber) and Southern Pacific (C. oreganus helleri) Rattlesnakes in Southern California. Pp. 353-364 in W. K. Hayes, K. R. Beaman, M. D. Cardwell, and S. P. Bush (eds.), The Biology of Rattlesnakes. Loma Linda University Press. 2008.
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The following status listings come from the Special Animals List which is published by the California Department of Fish and Wildlife.
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Organization
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Status Listing
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| U.S. Endangered Species Act (ESA) |
None |
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| California Endangered Species Act (CESA) |
None |
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| California Department of Fish and Wildlife |
DFG:SSC |
California Species of Special Concern |
| Bureau of Land Management |
None |
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| USDA Forest Service |
None |
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| Natureserve Global Conservation Status Ranks |
G4 S2? |
Apparently Secure |
World Conservation Union - IUCN Red List
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None |
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