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Masticophis lateralis

(Hallowell, 1853)

Striped Racer

G4Apparently Secure Found in 92 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
Least concernIUCN
PSESA Status
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.103313
Element CodeARADB21030
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusMasticophis
USESAPS
Synonyms
Coluber lateralis(Hallowell, 1853)
Other Common Names
California Whipsnake (EN) striped racer (EN)
Concept Reference
Jennings, M. R. 1983. Masticophis lateralis. Cat. Am. Amph. Rept. 343.1-343.2.
Taxonomic Comments
Nicholson (2025) is following Myers et al. (2017) in recognizing Masticophis as a genus.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-11-10
Change Date1996-10-30
Edition Date2025-11-10
Edition AuthorsHammerson, G. (2005); rev. R. L. Gundy (2025)
Threat ImpactMedium
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
This species is widespread and generally common in California and Baja California. The population has suffered minor historical declines and habitat fragmentation due to urbanization. Continuing threats include habitat loss, habitat fragmentation, and road mortality.
Range Extent Comments
The range extends from north-central California southward along the coast and the western slope of the Sierra Nevada through southwestern California to northwestern Baja California and as scattered records to near La Paz in southern Baja California (Jennings 1983, Grismer and Mahrdt 1996, Grismer 2002, Stebbins 2003). Elevational range extends from near sea level to about 2,250 meters (7,400 feet) (Stebbins 2003).
Occurrences Comments
This species is represented by many occurrences or subpopulations (Jennings 1983).
Threat Impact Comments
Some local populations likely are declining as a result of habitat loss resulting from urbanization (Richmond et al. 2016). Highways and urbanization prevent dispersal and gene flow (Richmond et al. 2016, Delaney et al. 2021). Mortality from vehicle and bicycle strikes while basking is a localized threat (Miller and Alvarez 2016). Major wildfires can cause local declines, at least in the short-term, due to degrading habitat suitability for this species (Rochester et al. 2010).
Ecology & Habitat

Description

A slender-bodied, fast-moving snake with a narrow neck and relatively broad head with large eyes; dorsum dark brown with a yellowish or orange stripe on each side; ventral surface is plain cream colored, pink, and/or orange; adults generally are 90-124 cm in total length. The pattern of spotting under the chin is unique and can be used to identify individuals throughout their lives (Murphy and Alvarez 2023).

Habitat

Habitats include chaparral foothills, shrublands with scattered grassy patches, rocky canyons and watercourses, oases in drier regions, mixed deciduous and pine woodlands in the mountains, and semidesert (in Baja California) (Grismer 2002, Stebbins 2003). This snake retreats underground or under cover when inactive. It lays eggs probably most often in abandoned rodent burrows, perhaps also in other protected sites underground or under imbedded objects.

Ecology

In the S.F. Bay Area, home range was reported as 2-8.7 ha (Federal Register, 4 February 1994).

Reproduction

Breeds in the spring. Lays a clutch of 6-11 eggs, May-July (Stebbins 1985). Eggs hatch August to October (Behler and King 1979).
Terrestrial Habitats
Woodland - HardwoodWoodland - MixedShrubland/chaparralSavannaGrassland/herbaceous
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN4
ProvinceRankNative
CaliforniaSNRYes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
1.1 - Housing & urban areasLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
1.2 - Commercial & industrial areasLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
4 - Transportation & service corridorsSmall (1-10%)Slight or 1-10% pop. declineHigh (continuing)
4.1 - Roads & railroadsSmall (1-10%)Slight or 1-10% pop. declineHigh (continuing)
7 - Natural system modificationsRestricted - smallModerate or 11-30% pop. declineHigh (continuing)
7.1 - Fire & fire suppressionRestricted - smallModerate or 11-30% pop. declineHigh (continuing)
7.1.1 - Increase in fire frequency/intensityRestricted - smallModerate or 11-30% pop. declineHigh (continuing)

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Roadless Areas (92)
California (92)
AreaForestAcres
AgnewSequoia National Forest9,561
AntimonyLos Padres National Forest40,911
Arroyo SecoAngeles National Forest4,703
BackboneShasta-Trinity National Forest11,466
Bear MountainLos Padres National Forest913
Bell QuinbyShasta-Trinity National Forest11,556
Big Butte ShinboneMendocino National Forest4,265
Big RocksLos Padres National Forest11,866
Black ButteLos Padres National Forest5,116
Black MountainLos Padres National Forest16,818
Black Mtn.Sequoia National Forest15,102
Cactus Springs BSan Bernardino National Forest3,106
Cahuilla MountainSan Bernardino National Forest6,952
CajonSan Bernardino National Forest7,548
CalienteCleveland National Forest5,953
CamuesaLos Padres National Forest8,209
ChannellSequoia National Forest45,429
ChicoSequoia National Forest39,836
Circle MountainSan Bernardino National Forest6,375
City CreekSan Bernardino National Forest9,997
ColdwaterCleveland National Forest8,402
Crystal CreekSan Bernardino National Forest6,783
Cucamonga AAngeles National Forest1,249
Cucamonga BSan Bernardino National Forest11,933
Cucamonga CSan Bernardino National Forest4,106
Cutca ValleyCleveland National Forest14,530
Deep CreekSan Bernardino National Forest23,869
Devil GulchSierra National Forest30,490
DiableLos Padres National Forest19,597
Dinkey LakesSierra National Forest34,171
Dog CreekShasta-Trinity National Forest5,001
Dry LakesLos Padres National Forest17,043
Eagle PeakCleveland National Forest6,481
Elk CreekMendocino National Forest23,182
Ferguson RidgeSierra National Forest6,104
Fish CanyonAngeles National Forest29,886
Fox MountainLos Padres National Forest52,072
Garcia MountainLos Padres National Forest7,850
Granite PeakSan Bernardino National Forest450
Greenhorn CreekSequoia National Forest28,226
Hixon FlatSan Bernardino National Forest8,095
Horse Creek RidgeSan Bernardino National Forest8,969
IshiLassen National Forest21,805
JuncalLos Padres National Forest12,289
Kings RiverSierra National Forest52,999
LaddCleveland National Forest5,300
Little French CShasta-Trinity National Forest11,529
Los Machos HillsLos Padres National Forest11,112
Machesna MountainLos Padres National Forest12,271
Magic MountainAngeles National Forest15,542
Malduce BuckhornLos Padres National Forest14,177
ManzanaLos Padres National Forest2,101
MatilijaLos Padres National Forest5,218
Mill CreekLassen National Forest7,587
Mill CreekSequoia National Forest27,643
Mill PeakSan Bernardino National Forest7,884
Mirada PimeLos Padres National Forest13,302
MonarchSierra National Forest697
MonoLos Padres National Forest28,141
MosesSequoia National Forest22,077
No NameCleveland National Forest4,897
NordhoffLos Padres National Forest12,031
Oat Mtn.Sequoia National Forest12,223
Pine CreekCleveland National Forest503
Pleasant ViewAngeles National Forest26,395
Pyramid Peak BSan Bernardino National Forest7,194
QuatalLos Padres National Forest7,253
Raywood Flat BSan Bernardino National Forest11,373
RinconSequoia National Forest54,610
Rouse HillSan Bernardino National Forest13,745
Salt CreekAngeles National Forest11,022
San DimasAngeles National Forest7,160
San Gabriel AddAngeles National Forest2,527
San SevaineSan Bernardino National Forest6,866
Santa CruzLos Padres National Forest21,182
Sawmill - BadlandsLos Padres National Forest51,362
Sespe - FrazierLos Padres National Forest106,910
Sheep MountainAngeles National Forest21,098
Sill HillCleveland National Forest5,294
Snow MountainMendocino National Forest14,457
Strawberry PeakAngeles National Forest7,245
Sycamore SpringsSierra National Forest10,015
TequepisLos Padres National Forest9,080
Thomes CreekMendocino National Forest16,616
TrabucoCleveland National Forest23,341
Trumbull PeakStanislaus National Forest6,164
TuleAngeles National Forest9,861
West ForkAngeles National Forest1,169
WestforkAngeles National Forest4,407
White LedgeLos Padres National Forest18,632
WildhorseCleveland National Forest1,483
WoodpeckerSequoia National Forest11,936
References (27)
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  2. California Department of Fish and Game (CDF&G). 1990. 1989 annual report on the status of California's state listed threatened and endangered plants and animals. 188 pp.
  3. Collins, J. T. 1990. Standard common and current scientific names for North American amphibians and reptiles. 3rd ed. Society for the Study of Amphibians and Reptiles. Herpetological Circular No. 19. 41 pp.
  4. Crother, B. I. (editor). 2012. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 7th edition. SSAR Herpetological Circular 39:1-92.
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  14. Miller, A., and J. A. Alvarez. 2016. Habitat use and management considerations for the threatened Alameda whipsnake (<i>Masticophis lateralis euryxanthus</i>) in central California. Western Wildlife 3: 29–32.
  15. Murphy, A. C., and J. A. Alvarez. 2023. Using chin spot pattern to differentiate individual <i>Masticophis lateralis</i> (Hallowell, 1853) on the Pacific Coast of the United States. Herpetology Notes 16: 615-618.
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  18. Nicholson, K. E. (ed.). 2025. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. Ninth Edition. Society for the Study of Amphibians and Reptiles. 87pp. Online database available at: https://cnah.org/SSARnames.aspx
  19. Pilliod, D. S., L. A. Hallock, M. P. Miller, T. D. Mullins, and S. M. Haig. 2020. Conservation genetics of the imperiled striped whipsnake in Washington, USA. Herpetological Conservation and Biology 15(3): 597–610.
  20. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
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  22. Richmond, J. Q., D. A. Wood, K. E. Swaim, R. N. Fisher, and A. G. Vandergast. 2016. Historical habitat barriers prevent ring-like genetic continuity throughout the distribution of threatened Alameda striped racers (<i>Coluber lateralis euryxanthus</i>). Herpetologica 72(3): 202-213.
  23. Rochester, C. J., C. S. Brehme, D. R. Clark, D. C. Stokes, S. A. Hathaway, and R. N. Fisher. 2010. Reptile and amphibian responses to large-scale wildfires in southern California. Journal of Herpetology 44(3): 333–351.
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  26. U.S. Fish and Wildlife Service (USFWS). 5 December 1997. Determination of endangered status for the callippe silverspot butterfly and the Behren's silverspot butterfly and threatened status for the Alameda whipsnake. Federal Register 62(234):64306-64320.
  27. Utiger, U., B. Schätti, and N. Helfenberger. 2005. The Oriental colubrine genus <i>Coelognathus </i>Fitzinger, 1843, and classification of old and new world racers and ratsnakes (Reptilia, Squamata, Colubridae, Colubrinae). Russian Journal of Herpetology 12(1):39-60.