California Reptiles & Amphibians

Crotalus ruber - Red Diamond Rattlesnake



Click on a picture for a larger view




Range in California: Red







Venomous and Potentially Dangerous!

Adult, San Diego County desert
Adult, San Diego County
© Jason Jones
Juvenile, desert slope of San Diego County mountains
Adult, coastal Riverside County
© 2005 Jeremiah Easter
Adult, San Diego County,
courtesy of Tim Burkhardt
Adult, coastal Riverside County
© Brad Alexander
Adult, San Diego County
© John Stoklosa
Adult, San Diego County
© Ryan Shatto
Adult, San Diego County
© Ryan Shatto
Juvenile, San Diego County
© Patrick Briggs
Tail
Adult, Riverside County
© Michael Clarkson
Habitat, Riverside County © Brian Hinds


Habitat, coastal Riverside County
Habitat, Riverside County -
riparian desert foothills
Habitat, desert slope of
San Diego County mountains
Habitat, coastal chaparral,
San Diego County
Habitat, San Diego County


Habitat, San Diego County palm oasis
Habitat, San Diego County
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rattlesnake signs.

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.


 
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.
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. Newly-hatched 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.)
Reproduction
Live-bearing; young born July - September. Male to male combat occurs.
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.

Taxonomy
Family Viperidae Vipers
Genus Crotalus Rattlesnakes
Species


ruber Red Diamond Rattlesnake
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

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

Alternate Names
Crotalus exsul

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

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.

Conservation Status

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.


Organization
Status Listing
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Game DFG:SSC California Species of Special Concern
Bureau of Land Management None
USDA Forest Service None
Natureserve Global Conservation Status Ranks G4 Apparently Secure
World Conservation Union - IUCN Red List




None

 

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