The great California herpetologist and rattlesnake expert Laurence Klauber left this little piece of herpetological history on a support column underneath a highway bridge in the San Diego County desert. He wrote:
"L. Klauber caught Crotalus m. pyrrhus here, 1953."
It remained untouched for almost 50 years when I first saw it. When I returned a year later to get a picture, it was partly painted over as you can see here. It is now completely painted over, but Klauber's essential book on rattlesnakes still remains.
Southwestern Speckled Rattlesnakes From Outside California
A coiled Southwestern Speckled Rattlesnake rattles, uncoils, and crawls into a bush. (Some loud background noise has been deleted in the middle of the video.)
A speckled rattlesnake crawls across a road and up into a bush in Imperial County.
A speckled rattlesnake rattles from up in a bush in Imperial County.
A large adult speckled rattlesnake rattling and crawling away on a windy night.
Listen to a rattlesnake rattling.
Anza-Borrego State Park warning sign.
Click the picture to see more rattlesnake warning 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 as vicious and always ready to attack without provocation. They will not strike without a reason, but they will aggressively defend themselves. They are often portrayed with the body partly coiled, the tail rattling loudly, and the head up ready to strike. This display is a warning not to come any closer or they will strike; a defensive behavior that some rattlesnakes use when they sense that crawling away would put them in danger. If they are given some space and some time to escape to a safe place, they will usually crawl away as fast as possible.
Because they cannot crawl to safety as fast as some snakes, rattlesnakes often use their cryptic color and pattern to blend into their surroundings in order to hide from their prey and from other animals that could threaten them. They often hunt by sitting still and waiting for a warm-blooded prey animal to pass close enough for the snake to strike it. Sometimes a passing human will be struck instead, mistaken for food. When they sense the presence of something that might threaten them, rattlesnakes 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
Dangerously Venomous(Poisonous)
A bite by this snake can be very dangerous without immediate medical treatment. Treatment can require hospitalization and great expense.
Size
Adults are 23-52 inches in length (58-132 cm) averaging 2 - 3.5 feet.
Young 8.5 - 10.5 inches.
Appearance
A long, heavy-bodied pit viper, with a thin neck, a large triangular head, and a rattle on the end of the tail consisting of loose interlocking hollow segments.
A new rattle segment is added each time the skin is shed, which can be more than one time per year.
Pupils are elliptical.
Scales are keeled.
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.
Color and Pattern
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.
The tail rings are in considerable color contrast with the body color, with the terminal rings being black and with an ash-gray ground color on the tail often present. Compare with C. stephensi.
Young
Newborn snakes do not have a rattle - just a single button which does not make a sound.
Similar Snakes
Found in sympatry with other species of rattlesnakes, including Crotalus ruber,Crotalus oreganus helleri, Crotalus atrox, Crotalus scutulatus and Crotalus cerastes. Can be differentiated from these species by color, pattern, and tail rings, and the lack of horns over the eyes.
Very similar to Crotalus stephensi, which was once thought to be the same species. Information on differentiating the two species can be found here.
Life History and Behavior
Activity
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.
Sound - The Rattle
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 and Feeding
Eats small mammals, lizards, and birds.
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.
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.
Rattlesnakes are ovoviparous. The mother keeps her fertilized eggs inside her body and gives birth to living young.
Females probably start bearing young at three years of age and breed annually. (Klauber, 1982)
Breeding occurs in the spring.
Two to 12 young are born in July or August. (Stebbins & McGinnis, 2013)
Adult males engage in a ritual "Combat Dance" during the spring breeding season. Necks and forebodies are intertwined, with the stronger snake slamming the smaller one to the ground until the weaker snake leaves the area.
"...The presence of a female is not necessary to stimulate the males to dance." (Klauber, 1982)
Geographical Range
This subspecies, Crotalus mitchellii pyrrhus - Southwestern Speckled Rattlesnake, is found throughout much of southern California north to aproximately the Mojave river, east into Nevada and extreme southwest Utah, south into Arizona and southern Baja California Norte.
The species Crotalus mitchellii is found from California south to the cape region of Baja California, Mexico, and east into Nevada, Utah, and Arizona.
Elevational Range
From
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.
Notes on Taxonomy
In a 2007 paper, * using molecular data, Douglas et al showed that this snake is a distinct species, not a subspecies of Crotalus mitchellii.
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, 1957.
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.
* Douglas, Michael E., 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.
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.
This animal is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.
