CaliforniaHerps.com

A Guide to the Amphibians
and Reptiles of California


Southern Pacific Rattlesnake - Crotalus oreganus helleri

Meek, 1905

(=Crotalus helleri )
Click on a picture for a larger view




Range in California: Blue

Click the map for a guide
to the other subspecies.




observation link



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southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnaked
Adult, San Diego County Adult, San Diego County
© Bruce Edley
Captive adult, courtesy of the Arizona-Sonora Desert Museum
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Adult, Ventura County
© Patrick Briggs
Adult, Ventura County
© Patrick Briggs
Adult, Ventura County
© Patrick Briggs
Adult, San Diego County
© Chris Gruenwald
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Adult, Santa Catalina Island
© Nathan Smith
Adult, Santa Catalina Island
© Nathan Smith
Adult, San Diego County
© 2003 Chris Gruenwald
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Adult, Los Angeles County  © Koby Poulton Adult, Riverside County
© Michael Clarkson
Snakes of two different color variations found in the same location in San Diego County. © Steve Bledsoe
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Adult, Los Angeles County © Gregory Litiatco Dark adult, San Bernardino County
© Jeff Ahrens
Intergrade with C. o. oreganus, Santa Barbara County © Benjamin German
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake  
This adult was found crossing a road one morning in San Diego County when it made a quick
U-turn and crawled back into a bush. You can see the tracks it made in these photos.
 
rattle southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Adult tail and rattle Adult tail and rattle Adult tail and rattle
© 2006 Koby Poulton

Juvenile tail and yellow button
Juveniles
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Juvenile with yellow tail, Los Angeles County
(Note that the rattle consists of only one segment which does not produce a sound.)
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Juvenile, Santa Monica Mountains,
Los Angeles County © Colin Byrne
Juvenile, about 12 inches in length, Orange County, flattening its body to appear larger. © David Fong

Juvenile, San Diego County © Lori Paul Juvenile, San Bernardino County
© Patrick Briggs
Unusual or Interesting Color and Pattern Variations
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Melanistic patternless adult, Riverside Count © Tony Covell Melanistic Adult, Ventura County
© Patrick Briggs
Melanistic adult, San Gabriel Mountains, Los Angeles County © Lori Paul.
This snake had a completely dark belly.
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Black  adult, Santa Monica Mountains, Los Angeles County
© Colin Byrne.
Black Southern Pacific rattlesnakes are common in southern California mountains.
Pale juvenile, Orange County © Steve Bledsoe Juvenile full from recent meal,
San Bernardino County © Jeff Ahrens
southern pacific rattlesnake      
Adult, San Bernardino Mountains, San Bernardino County © Stuart Williams.
This snake is ready to shed its skin, called being "in the blue," and it actually shows some blue coloring on the head and lower sides.
     
       
Breeding Behavior
southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake southern pacific rattlesnake
Steve Bledsoe, ©, photographed these two helleri mating in March in San Diego County. Two adults, probably a mating pair, in San Diego County, as found underneath a board in March.

Males in "Combat Dance," Ventura County © 2006 Steve Broggie
Predation
California Kingsnake California Kingsnake California Kingsnake California Kingsnake
California Kingsnakes eat snakes along with other animals. They are immune to rattlesnake venom, so they
sometimes eat rattlesnakes. This one is eating a juvenile Southern Pacific Rattlesnake. © Kimberly Deutsch
This California Kingsnake is almost finished eating a juvenile Northern Pacific Rattlesnake.   © Michele Coughlin
southern pacific rattlesnake southern pacific rattlesnake California Mountain Kingsnake California Mountain Kingsnake
A California Striped Racer - Coluber lateralis lateralis, eats a juvenile Southern Pacific Rattlesnake in Los Angeles County. © Anthony

This Sierra Mountain Kingsnake is eating a juvenile
Northern Pacific Rattlesnake
, © Patrick Briggs
southern pacific rattlesnake southern pacific rattlesnake    
This California Kingsnake was discovered eating a juvenile Southern Pacific Rattlesnake in the Los Padres Mountains, Santa Barbara County © Benjamin Bruno    
       
Habitat
southern pacific rattlesnake habitat southern pacific rattlesnake habitat southern pacific rattlesnake habitat southern pacific rattlesnake habitat
Habitat, San Gabriel Mountains,
Los Angeles County
Habitat, San Diego County coastal scrub Habitat, Carlsbad, coastal
San Diego County.
(This location was bulldozed and developed a few years later.)
Habitat, San Gabriel Mountains, Los Angeles County
southern pacific rattlesnake habitat southern pacific rattlesnake habitat southern pacific rattlesnake habitat southern pacific rattlesnake habitat
Habitat, coastal Riverside County Coastal San Diego County grassland habitat that is rapidly disappearing due to development. © Brian Hinds Habitat, riparian canyon,
Los Angeles County
Den habitat, Los Angeles County
© Koby Poulton
southern pacific rattlesnake habitat southern pacific rattlesnake habitat    
Habitat, Santa Monica Mountains, Los Angeles County © Colin Byrne

Habitat, Santa Monica Mountains, Los Angeles County © Colin Byrne    
Short Video and Sounds
southern pacific rattlesnake speaker

   
A Southern Pacific Rattlesnake poses and rattles and crawls away at night in Los Angeles County. Listen to the rattling of a captive adult (shown above) courtesy of the Arizona-Sonora Desert Museum. © Jeff Rice / Western Soundscape Archive Not to be used without permission.

   
 
rattlesnake sign rattlesnake sign sign rattlesnake sign
San Diego County park warning sign.


Sign at Santa Barbara
County rest area
Sign in San Gabriel Mountains Click on the picture to see more
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.

"Rattlesnakes are also among the most reasonable forms of dangerous wildlife: their first line of defense is to remain motionless; if you surprise them or cut off their retreat, they offer an audio warning; if you get too close, they head for cover. Venom is intended for prey so they're reluctant to bite, and 25 to 50 percent of all bites are dry - no venom is injected."
Leslie Anthony. Snakebit: Confessions of a Herpetologist. Greystone Books, 2008.

Rattlesnake bites can be extremely dangerous, but rattlesnakes should not be considered vicious and aggressive. They are often called aggressive in movies and stories, but they will not attack without a reason. The image of a rattlesnake 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 some rattlesnakes use when they sense that crawling away would put them in danger of an attack. This display is a warning not to come any closer or they will strike. If they are given some space and some time to escape to a safe place, they will do so quickly.

Because they cannot move very quickly rattlesnakes often use their cryptic color and pattern to blend into their surroundings to hide from their prey and from other animals that could threaten them. When threatened, they often lie still to avoid detection and do not rattle, because that would give away their location. At other times they rattle loudly, 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 which they need to kill and digest their food.

Description

Venomous
The venom of this snake is potentially dangerous to humans.
Size
Adults 30 - 44 inches long, sometimes up to 54 inches. Newborns about 10 inches long.
Appearance
A heavy-bodied, venomous pit viper, with a thin neck and a large triangular head. Pupils are elliptical. Scales are keeled.

Ground color is brown to olive-brown. Dark brown blotches, completely outlined by light pigment, mark the back. These blotches turn to bars toward the tail, which is surrounded with dark rings. The last ring is not well-defined and is more than twice the width of the other rings. Young have a bright yellow tail. The underside is pale, sometimes weakly mottled.

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.

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.
Similar Subspecies
Notes on identifying subspecies of Western Rattlesnakes, Crotalus oreganus, found in California.
Behavior
Primarily nocturnal and crepuscular during periods of excessive daytime heat, but also active during daylight when the temperature is more moderate. Not active during cooler periods in Winter.

Prey is found while the snake is 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.

Radiotelemetry studies have shown that the home range of male snakes is larger than that of females.
Diet
Eats birds, lizards, snakes, frogs, insects, and small mammals, including mice, rats, rabbits, hares, and ground squirrels. (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 are born August - October. Breeding activity occurs twice per year - in the spring and in late summer/early fall. Male rattlesnakes search extensively for females during the mating season while females do not actively search for males. Male to male combat occurs.
Known to hybridize with the Northern Mohave Rattlesnake where their ranges overlap in the Antelope Valley.
Range
This subspecies, Crotalus oreganus helleri - Southern Pacific Rattlesnake, is found in California from Santa Barbara County, where there is a wide zone of intergradation with the Northern Pacific Rattlesnake north to around Morro Bay, east to the central valley and the desert slopes of the transverse and peninsular ranges, and south into the middle of the Baja California peninsula. Ranges north of the transverse ranges into the Mojave Desert in the Antelope Valley and just south of Barstow.
Also found on Santa Cruz and Santa Catalina Islands.

The species Crotalus oreganus - Western Rattlesnake, occurs from the Pacific Coast of northern Baja California north through most of California except the southern deserts, through Oregon and eastern Washington into British Columbia, Canada, and east into Nevada, Idaho, Utah, northern Arizona, extreme southwestern Wyoming, and extreme northwestern New Mexico.
Habitat
Found in a wide range of habitats from seaside dunes, to desert scrub, grassy plains, rocky hillsides, chaparral, open woodlands, and agricultural areas.
Taxonomic Notes
The taxonomy of Western Rattlesnakes is controversial and still being studied.

Some researchers still use the former species name Crotalus viridis and for them this snake remains Crotalus viridis helleri .

In a 2002 study, Douglas, Douglas, Schuett, Porras, & Holycross
[2002. Phylogeography of the Western Rattlesnake (Crotalus viridis) Complex, With Emphasis on the Colorado Plateau]. Pp. 11-50. In Biology of the Vipers [Schuett, Höggren, Douglas, and Greene (editors). Eagle Mountain Publishing, Eagle Mountain, Utah]
split C.viridis into 7 distinct species:

Crotalus oreganus oreganus
becomes Crotalus oreganus,
Crotalus oreganus helleri
becomes Crotalus helleri, and
Crotalus oreganus lutosus
becomes Crotalus lutosus.

The common names remain the same.

Some naturalists believe that rattlesnakes on Santa Catalina Island are distinct from those on the mainland and will be recognized as a different subspecies once DNA studies are completed.  LA Times Article 11/28/09

Conservation Issues  (Conservation Status)
None.
Taxonomy
Family Viperidae Vipers Crotalidae - Pitvipers
Genus Crotalus Rattlesnakes Linnaeus, 1758
Species oreganus Western Rattlesnake Holbrook, 1840
Subspecies


helleri Southern Pacific Rattlesnake Meek, 1905
Original Description
Crotalus viridis - Rafinesque, 1818 - Amer. Month. Mag. Crit. Rev., Vol. 4, No. 1, Nov. p. 41
Crotalus viridis helleri - Meek, 1905 - Field Columb. Mus. Publ. Zool., Vol. 7, p. 17

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
oreganus
- belonging to the state of Oregon - referring to the type locality, "banks of Oregon or Columbia River"
helleri - honors Heller, Edmund

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
Crotalus viridis helleri

Crotalus helleri

Timber Rattlesnake (It is not uncommon for a rattlesnake found in a forested area in California to be called a Timber Rattlesnake. The true Timber Rattlesnake (Crotalus horridus) is not found in California. It occurs from southeast Minnesota down to central Texas and east to northern Florida up to south-central New Hampshire.)
Related or Similar California Snakes
C. o. lutosus - Great Basin Rattlesnake
C. o. oreganus - Northern Pacific Rattlesnake
C. ruber - Red Diamond Rattlesnake
C. atrox - Western Diamond-backed Rattlesnake
C. s. scutulatus - Northern Mohave Rattlesnake
C. c. laterorepens - Colorado Desert Sidewinder

More Information and References
California Department of Fish and Wildlife

Living With Rattlesnakes

California Department of Fish and Game: Rattlesnakes in California

University of California: Rattlesnakes Management Guide

Tucson Herpetological Society: Living With Venomous Reptiles pdf

Florida Museum of Natural History: How to Get Along with Snakes

Southwestern Field Herping Associates: Venomous Snake Safety

Internet Center for Wildlife Damage Management - Rattlesnake Control / Snake Control


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, 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.


Conservation Status

The following status listings come from the Special Animals List and the Endangered and Threatened Animals List which are published by the California Department of Fish and Wildlife.




Organization
Status Listing
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Wildlife None
Bureau of Land Management None
USDA Forest Service None


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