A very fast San Joaquin Coachwhip races across a dirt road.
Not Dangerous (Non-poisonous) - This snake does not have venom that is dangerous to most humans.
Adults are 36 - 66 inches long (91 - 167 cm.) (Stebbins & McGinnis, 2012)
The only longer snake in California is the Gophersnake.
Hatchlings are about 13 inches long.
A slender fast-moving snake with smooth scales, a large head and eyes, a thin neck, and a long thin tail.
(There is no well-defined stripe lengthwise on the body in this species.)
Large scales above the eyes.
17 rows of scales at midbody.
The braided appearance of scales on the tail (like a whip) gives this species its common name.
Color and Pattern
Color is tan, olive brown, or yellowish brown.
Lacks the very dark head and neckbands of the other subspecies of Coluber found in California -C.f.piceus.
Life History and Behavior
Active in the daytime. Able to tolerate high temperatures.
Moves very quickly.
Emerges from winter site relatively late (April - May) due to the species preference for warm temperatures.
Coachwhips are good climbers, able to climb bushes and trees.
Often seen moving quickly even on hot sunny days, but often seen basking on roads in early morning or resting underneath boards or other surface objects.
Frequently run over by vehicles and found dead on the road, partly due to the tendency of this snake to stop and eat small road-killed animals.
Often strikes agressively when threatened or handled.
Diet and Feeding
Eats small mammals including bats, nestling and adult birds, bird eggs, lizards, snakes, amphibians, and carrion. Hatchlings and juveniles will eat large invertebrates.
The ability to tolerate high temperatures enables
this snake to hunt heat-dependant lizards when they are active. High speed allows it to run down the fast-moving
Hunts crawling with head the held high above the ground, occasionally moving it from side to side to aid in binocular vision and depth perception.
The prey is overcome and crushed with the jaws or crushed beneath loops of the body then eaten without constriction.
Presumably mates in May and lays a clutch of 4 - 20 eggs in early Summer (June - July). (Stebbins, 2003)
Occurs in open, dry, treeless areas with little or no cover, including valley grassland and saltbush scrub.
Avoids dense vegetation where it cannot move quickly, including mixed oak chaparral woodland.
Takes refuge in rodent burrows, under shaded vegetation, and under surface objects.
This subspecies, Coluber flagellum ruddocki - San Joaquin Coachwhip, is endemic to California, ranging from Arbuckle in the Sacramento Valley in Colusa County southward to the Grapevine in the Kern County portion of the San Joaquin Valley and westward into the inner South Coast Ranges. An isolated population occurs in the Sutter Buttes. Apparently intergrades with C. f. piceus in eastern Kem County.
The species Coluber flagellum - Coachwhip, occurs very widely across the southern half of the U.S. from southern California east to Florida, and far south into Mexico, including northeast Baja California.
Notes on Taxonomy
Coluber flagellum was formerly Masticophis flagellum
North American snakes formerly placed in the genus Masticophis have been changed to the genus Coluber based on a 2004 paper * by Nagy et al. Utiger et al. (2005, Russian Journal of Herpetology 12:39-60) supported Nagy et al. and synonymized Masticophis with Coluber. This has not been universally accepted. The most recent SSAR list has hinted that the genus Masticophis might be re-instated: "Burbrink (pers. comm.) has data to reject Nagy et al.’s hypothesis but we await publication of these data before reconsidering the status of Masticophis."
Designated a Species of Special Concern by the state of California due to extensive habitat loss and fragmentation in its restricted range, including conversion of large areas of suitable habitat to agricultural use in the San Joaquin Valley and urban development in areas of the inner Coast Ranges, both of which eliminate the snake's food base and the mammal burrows it uses for refuge.
"Much of this subspecies' historic range has undergone dramatic land use changes from grassland to intensive agriculture in the Central Valley. Masticophis flagellum ruddocki is thought to be sensitive to disturbance and does not persist in cultivated areas (Ernst and Ernst 2003; S.Barry, pers. comm.). It has therefore suffered a severe range contraction in its Central Valley range."
(Robert C. Thomson, Amber N. Wright, and H. Bradley Shaffer. California Amphibian and Reptile Species of Special Concern. University of California Press, 2016.)
North American Racers, Coachwhips and Whipsnakes
San Joaquin Coachwhip
(Brattstrom and Warren, 1953)
Masticophis flagellum - (Shaw, 1802) - Gen. Zool., Vol. 3, p. 475 Masticophis flagellum ruddocki - Brattstrom and Warren, 1953 - Herpetologica, Vol. 9, p. 177
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.
Samuel M. McGinnis and Robert C. Stebbins. Peterson Field Guide to Western Reptiles & Amphibians. 4th Edition. Houghton Mifflin Harcourt Publishing Company, 2018.
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.
* Z. T. Nagy, Robin Lawson, U. Joger and M. Wink. Molecular systematics of Racers, Whipsnakes and relatives (Reptilia: Colubridae) using Mitochondrial and Nuclear Markers. Journal of Zoological Systematics and Evolutionary Research (Volume 42 pages 223–233). 2004
Robert C. Thomson, Amber N. Wright, and H. Bradley Shaffer. California Amphibian and Reptile Species of Special Concern. University of California Press, 2016.
The following conservation status listings for this animal are taken from the November 2020 California "Special Animals List" and the November 2020 "State and Federally Listed Endangered and Threatened Animals of California" list, both of which are produced by multiple agencies and available here: https://www.wildlife.ca.gov/Data/CNDDB/Plants-and-Animals. You can check the link to see if there are more recent lists.
If no status is listed here, the animal is not included on either list. This most likely indicates that there are no serious conservation concerns for the animal. To find out more about an animal's status you can go to the NatureServe and IUCN websites to check their rankings.
The Special Animals List shows this snake as Masticophis flagellum ruddocki - San Joaquin coachwhip.
NatureServe Global Ranking
The species is: Secure—Common; widespread and abundant.
This subspecies is Imperiled - Vulnerable.
NatureServe State Ranking
Imperiled in the state because of rarity due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors making it very vulnerable to extirpation from the state.