California Reptiles & Amphibians

Crotalus mitchellii pyrrhus - Southwestern Speckled Rattlesnake



Click on a picture for a larger view




Range in California: Red

Green: Panamint Rattlesnake







Venomous and Potentially Dangerous!

Adult, Imperial County
© John Stoklosa

Adult, San Diego County
© Ryan Shatto

Adult, San Diego County © Bruce Edley
Adult, Mecca Hills, Riverside County
Adult, Santa Ana Mountains, Riverside County © 2005 Ken Pitts Close-up of a high-contrast Adult,
San Diego County
   
  Juvenile, San Bernardino County
© Michael Clarkson
 
Adult, Yuma County, Arizona
courtesy of Marty Feldner
Adult, Yavapai County, Arizona
Adult, Yavapai County, Arizona



Click on the play button or the speaker to hear a rattlesnake rattling
Rattle
The great California herpetologist Laurence Klauber made his mark on a highway bridge in the San Diego County desert, writing: "L. Klauber caught Crotalus m. pyrrhus here, 1953" It was tagged over 50 years later.
Habitat, San Diego County
Habitat, San Diego County
Habitat, Riverside County



Habitat, Riverside County
Anza-Borrego State Park warning sign.
Click 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.

 
Description
Venomous
The venom of this snake is potentially dangerous to humans.
Size
Adults are 23-52 inches in length (58-132 cm) averaging 2 - 3.5 feet. Young 8.5 - 10.5 inches.
Appearance
A heavy-bodied, venomous pit viper, with a thin neck and a large triangular head. Pupils are elliptical. Scales are keeled.

Shows a great variety of body coloration which usually allows the snake to blend into its environment, from off-white, yellowish, gray, tan, pinkish, pale orange, to brown. Snakes from dark lava bed environments can be almost all black. The body is marked with a vague pattern consisting of dark speckled banded markings. Dark and light rings surround a thick tail with a rattle on the end, consisting of loose interlocking segments. A new rattle segment is added each time the skin is shed.

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. Not active during cooler periods in Winter.

An ambush hunter, it may wait 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. Prey is also found while the snake is actively moving.

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, lizards, and birds.
Reproduction
Live-bearing; young born July and August.
Range
Found throughout much of southern California, including coastal areas, north to aproximately the Mojave river, east into Nevada and extreme southwest Utah, south into Arizona and southern Baja California Norte. Sea level to 8,000 ft. (2,440 m).
Habitat
Associated mostly with arid areas strewn with rocks and boulders - alongside buttes, mesas, and desert outcroppings, but sometimes found on loose soil. Occurs in areas vegetated by sagebrush, creosote, thornscrub, chaparral, pinon-juniper woodland, succulent desert.
Taxonomic Notes
MICHAEL E. DOUGLAS, MARLIS R. DOUGLAS, GORDON W. SCHUETT, LOUIS W. PORRAS, AND
BLAKE L. THOMASON (Genealogical Concordance between Mitochondrial and Nuclear DNAs Supports Species Recognition of the Panamint Rattlesnake (Crotalus mitchellii stephensi) Copeia, 2007(4), pp. 920–932) using molecular data, showed that Crotalus stephensi is a unique species, not a subspecies of Crotalus mitchellii.

Taxonomy
Family Viperidae Vipers
Genus Crotalus Rattlesnakes
Species mitchellii Speckled Rattlesnake
Subspecies

pyrrhus Southwestern Speckled Rattlesnake
Original Description
Crotalus mitchellii - (Cope, 1861) - Proc. Acad. Nat. Sci. Philadelphia, Vol. 13, p. 293
Crotalus mitchellii pyrrhus - (Cope, "1866" 1867) - Proc. Acad. Nat. Sci. Philadelphia, Vol. 18, p. 308

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
mitchellii
- honors Mitchell, S. Weir
pyrrhus - Greek - pyrrhos - flame colored, reddish

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

Alternate Names
None

Related or Similar California Snakes
More Information and References
Natureserve Explorer

California Dept. of Fish and Game

SDNHM

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.

This animal is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.


Organization
Status Listing
U.S. Endangered Species Act (ESA)
California Endangered Species Act (CESA)
California Department of Fish and Game
Bureau of Land Management
USDA Forest Service
Natureserve Global Conservation Status Ranks
World Conservation Union - IUCN Red List





 

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