California Reptiles & Amphibians

Crotalus oreganus lutosus - Great Basin Rattlesnake

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Range in California: Orange

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to the other subspecies.

Venomous and Potentially Dangerous!

Adult, from the eastern border of Siskiyou county

Adult, Mono County © Michael Clarkson. Specimen courtesy of Jeff Mintz

Juvenile, Mono County © Michael Clarkson. Specimen courtesy of Jeff Mintz

Adult, Mono County
© David Tobler

Adult, Washoe County, Nevada

Adult, Mineral County, Nevada.
© Brad Alexander

Juvenile, Washoe County, Nevada
© Don Johnson

Den site in Washoe County, Nevada, where snakes have been seen for at least 20 years.
© Tom Green - TomGreenPhotography.com

Adult in habitat, Mineral County, Nevada.
© Brad Alexander

Adult C. o. oreganus, Greenhorn Mountains, Kern County

Crotalus oreganus oreganus near its southern range limit is variable in appearance, often looking very much like C. o. lutosus. An example is the Kern County snake seen in the row above. Identification of rattlesnakes found in this region can be confusing and open to debate. Some of these controversies should be resolved when the results of further studies on these species are published.

According to Robert Hansen who has studied the area in depth: "Among populations of "oreganus" inhabiting arid landscapes near their southern range limits (e.g., southern San Joaquin Valley, Carrizo Plain), there is a tendency toward small size, light ground color, and reduced dorsal blotch size...features that cause these snakes to superficially resemble lutosus."..."The southern extent of the range of lutosus in eastern California (e.g., the Mono/Inyo counties region) has been mapped in reasonable detail, and thus far, there are no known instances where the ranges of oreganus and lutosus come into contact.
However, farther north, where the Sierra Nevada crest is much lower and the potential for populations of oreganus and lutosus to meet is likely greater, careful field studies are lacking. Ultimately, reliance on features of coloration and pattern to distinguish one form from the other in areas of potential contact is not advised."

Habitat, 4,400 ft. Siskiyou county

Habitat, 4,300 ft. Siskiyou county

Habitat, Surprise Valley, Modoc County

Habitat, Mono County

Click on the play button or the speaker to hear a Great Basin Rattlesnake rattling.
© Jeff Rice
(Listen to more recordings of this snake at the Western Soundscape Archive)
Not to be used without permission.

More Rattlesnake sounds and videos

Tail

California rest stop warning sign.
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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 of this species range from 15 - 65 inches long, ( 38 - 165 cm) but typically the adults seen are 3 - 4 feet long. Newborns are around 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. Two light stripes extend diagonally across the sides of the head, but they are sometimes faded and not evident.

The ground color is variable, matching the environment - pale grey, tan, light yellow, buff colored. The back is marked with dark blotches with light centers, usually in the shape of bars or ovals, about as wide as the spaces between them. The underside is pale, sometimes weakly mottled.

The tail is barred, and without white rings. 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.

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.

Diet

Eats small mammals, including ground squirrels, mice, rats, rabbits and hares, birds, lizards, snakes, frogs, and insects.

Reproduction

Bears live young.

Range

Found in California in the far northeastern corner and in a small region east of the Sierras near the Mono Lake area. Ranges north into eastern Oregon, and east to western Utah, southern Idaho, most of Nevada, and barely into northwest Arizona.

Habitat

Inhabits rocky hillsides, barren flats, sagebrush, grassy plains, and agricultural areas.

Taxonomic Notes

The taxonomy of Western Rattlesnakes is controversial and still being studied.
Some researchers still use the name which this snake held for many years: Crotalus viridis lutosus. Others have split C.viridis into 7 distinct species, including Crotalus lutosus.

Conservation Issues (Conservation Status)

None.

Taxonomy
Family	Viperidae	Vipers
Genus	Crotalus	Rattlesnakes
Species	oreganus	Western Rattlesnake
Subspecies	lutosus	Great Basin Rattlesnake
Original Description
Crotalus viridis - Rafinesque, 1818 - Amer. Month. Mag. Crit. Rev., Vol. 4, No. 1, Nov. p. 41 Crotalus viridis lutosus - Klauber, 1930 - Trans. San Diego Soc. Nat. Hist., Vol. 6, No. 3, p. 100 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" lutosus - Latin - muddy, full of mud - referring to the brownish dorsal color from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
Alternate Names
Known for many years as Crotalus viridis lutosus. Crotalus lutosus.
Related or Similar California Snakes
C. o. helleri - Southern Pacific Rattlesnake C. o. oreganus - Northern Pacific Rattlesnake C. atrox - Western Diamond-backed Rattlesnake C. s. scutulatus - Northern Mohave Rattlesnake C. m. stephensi - Panamint 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 University of California: Rattlesnakes Management Guide 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.

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 snake 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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