A Guide to the Amphibians
and Reptiles of California

Sceloporus occidentalis bocourtii - Coast Range Fence Lizard

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Range in California: Green

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to the other subspecies

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Adult female, San Benito County

Adult female, San Mateo County

Adult male, Contra Costa County

Adult female, Contra Costa County

Adult male, Contra Costa County

Adult female, San Mateo County

Adult female, Contra Costa County

Adult with a nice view of the Golden Gate Bridge, Contra Costa County

Adult female, San Luis Obispo County

Juvenile, Contra Costa County

Adult, Monterey County

Adult, Marin county, showing salt excreted from its nares (nostrils).
© 2001 Guntram Deichsel

Adult male, Monterey County

Adult, Alameda County

Adult, Solano County

Predation and Parasites

California Striped Racer eating a male Great Basin Fence lizard

Sean Kelly © shot this series of a California Striped Racer eating a male Great Basin Fence lizard in San Diego County.

Pacific Gopher Snake eating a Western Fence Lizard

California Striped Racers eat mosly lizards. This one is swallowing a Western Fence Lizard while holding the front third of its body straight up off the ground. This racer usually hunts with its head in this elevated position.

Juvenile Pacific Gopher Snake eating a Western Fence Lizard © Daniel Harris

Adult male with ticks on the side of his head.

In California, western black-legged ticks (deer ticks) are the primary carriers of Lyme disease. Very tiny nymphal deer ticks are more likely to carry the disease than adults. A protein in the blood of Western Fence Lizards kills the bacterium in these nymphal ticks when they attach themselves to a lizard and ingest the lizard's blood. This could explain why Lyme disease is less common in California than it is in some areas such as the Northeastern states, where it is epidemic.

More Information

Juvenile fence lizards are preyed upon by many other animals, including the black widow spider. © Rory Doolin

Some Characteristics Useful In Separating Western Fence Lizards from Common Sagebrush Lizards

Dorsal view - Common Sagebrush Lizard, Sceloporus graciosus, on the left, Western Fence Lizard, Sceloporus occidentalis, on the right. Note the larger dorsal scales on the Fence Lizard.
© Patrick Briggs

Head view - Common Sagebrush Lizard on the left, Western Fence Lizard on the right. © Patrick Briggs

Ventral view - Western Fence Lizard on the left, Common Sagebrush Lizard on the right. Note the yellow on the back of the thighs on the Western Fence Lizard.
© Patrick Briggs

Underside of adult male Western Fence Lizard showing yellow on the back of the thighs and enlarged femoral pores.

Comparison of the rear thighs of a Common Sagebrush Lizard - on top, and a Western Fence Lizard - on the bottom.

Note the granular scales on the Common Sagebrush Lizard and the keeled (and yellow) scales on the Western Fence Lizard.

A Common Sagebrush Lizard on the left basking next to a Western Fence Lizard on the right.

Habitat

Habitat, Contra Costa County

Sandy wash with rocky edge habitat,
San Benito County

Lizard in habitat, Alameda County

Habitat, Monterey County

Habitat, San Luis Obispo County

Habitat, Contra Costa County

Habitat, East Bay Hills, Contra Costa County

Coastal scrub habitat, Marin County

Coastal dunes habitat, Monterey County

Habitat, Contra Costa County

Short Videos

A few fence lizards in Contra Costa County.

A male fence lizard on a tree in Alameda County.

Several juvenile fence lizards come out to bask in the sun on a cool and windy morning in early March.

Two Coast Range Fence Lizards observed during the breeding season in early May in San Benito County. The first lizard, a female, has moved from her perch on a rock to a nearby rock in order to get away from the photographer. She begins a territorial push-up display when a male comes up the side of the rock and begins to pursue her. She arches her back and hops away in order to reject him. She may have already mated and is bearing eggs, or maybe he is not her type. He finally stops and does a push-up display, possibly to continue trying to entice her, or possibly to warn the photographer that this is his territory.

Description

Size

2.25 - 3.5 inches long from snout to vent (5.7 - 8.9 cm). (Stebbins 2003)

Appearance

A fairly small lizard with keeled and pointed dorsal scales of equal size on the back, sides, and belly. Scales on the backs of the thighs are mostly keeled, and abruptly smaller, and the rear of the limbs is yellow or orange. The sides of the belly are blue.

Color is brown, gray, or black with blotches. Sometimes light markings on the sides of the back form stripes or irregular lines, and sometimes dark blotching may form irregular bands.

Males have blue markings on the sides of the belly edged in black, a blue patch on the throat, enlarged postanals, and a swollen tail base. Some scales on the back become blue or greenish when a lizard is in the light phase.

Females have faint or absent blue markings on the belly, no blue or green color on the upper surfaces, and dark bars or crescents on the back.

Juveniles have little or no blue on the throat and faint blue belly markings or none at all.

Behavior and Natural History

Diurnal. Often seen basking in the sun on rocks, downed logs, trees, fences, and walls. Prefers open sunny areas.
Active when temperatures are warm, becomes inactive during periods of extreme heat or cold, when they shelter in crevices and burrows, or under rocks, boards, tree bark, etc.

Common and easily encountered in the right habitat. This is probably the species of lizard most often seen in the state due to its abundance in and near populated areas and its conspicuous behavior.

Males defend their territory and try to attract females with head-bobbing and a push-up display that exposes the blue throat and ventral colors.

The tail detaches easily to distract a potential predator allowing the lizard to escape.

Diet

Eats small, mostly terrestrial, invertebrates such as crickets, spiders, ticks, and scorpions, and occasionally eats small lizards including its own species.

Reproduction

Mates in early to late spring, depending on the elevation of the location.

Males establish and defend a territory containing elevated perches where they can observe mates and potential rival males. Territories are defended by posturing and by physical combat with other males.

Courtship and copulation typically occurs from March to June. Egg laying occurs 2 - 4 weeks after copulation. Females dig small pits in loose damp soil where they lay 1 - 3 clutches of 3 - 17 eggs usually from May to July. Eggs hatch in about 60 days, usually from July to September.

Range

This subspecies is endemic to California. Found from north of the San Francisco Bay Area south throughout the Bay Area to Santa Barbara County.
The species Sceloporus occidentalis ranges from northern Baja California north to Washington and east to Idaho, Nevada and Utah.

Habitat

Found in a wide variety of open, sunny habitats, including woodlands, grasslands, scrub, chapparal, forests, along waterways, suburban dwellings, where there are suitable basking and perching sites, including fences, walls, woodpiles, piles of rocks and rocky outcrops, dead and downed trees, wood rat nests, road berms, and open trail edges.

Taxonomic Notes

The taxonomy of Sceloporus occidentalis needs to be studied further. For years six subspecies have been recognized based on geographic variation in morphology, but molecular studies have identified 4 major clades and 11 different genetic groups in California (James Archie, Cal State University Long Beach).

Many authorities have already accepted research that concludes that S. o. becki, the Island Fence Lizard, is a unique species - Sceloporus becki. (Wiens & Reeder, 1997) (Bell, 2001)

The current taxonomy does not correspond with the ongoing research, so it is certain that in the future the current subspecies and their ranges will be completely revised, probably with several new species described. For this reason some experts no longer recognize any subspecies of S. occidentalis pending further studies. This site follows the SSAR list of 2008 and continues to recognize 6 subspecies.

The range map is based on Ryan Calsbeek's distribution map.

Conservation Issues (Conservation Status)

None.

Taxonomy
Family	Phrynosomatidae	Zebra-tailed, Earless, Fringe-toed, Spiny, Tree, Side-blotched, and Horned Lizards
Genus	Sceloporus	Spiny Lizards
Species	occidentalis	Western Fence Lizard
Subspecies	bocourtii	Coast Range Fence Lizard
Original Description
Sceloporus occidentalis - Baird and Girard, 1852 - Prox. Acad. Nat. Sci. Philadelphia, Vol. 6, p. 175 Sceloporus occidentalis bocourtii - Boulenger, 1885 - Cat. Liz. Brit. Mus., 2nd ed., Vol. 2, p. 229 from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
Meaning of the Scientific Name
Sceloporus - Greek -skelos leg and porus - pore or opening - refers to the femoral pores on hind legs occidentalis - Latin - western - refers to its western distribution bocourtii - Latin - honors Bocourt, Marie F. from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
Alternate Names
Bluebelly or Blue-bellied Lizard Fence Lizard Swift Sceloporus occidentalis - Western Fence Lizard (no subspecies recognized)
Related or Similar California Lizards
Western Fence Lizards: Sceloporus occidentalis becki - Island Fence Lizard Sceloporus occidentalis biseriatus - San Joaquin Fence Lizard Sceloporus occidentalis longipes - Great Basin Fence Lizard Sceloporus occidentalis occidentalis - Northwestern Fence Lizard Sceloporus occidentalis taylori - Sierra Fence Lizard Sagegrush Lizards: S. graciosus graciosus - Northern Sagebrush Lizard S. graciosus gracilis - Western Sagebrush Lizard S. graciosus vandenburgianus - Southern Sagebrush Lizard Sceloporus magister uniformis - Yellow-backed Spiny Lizard
More Information and References
Natureserve Explorer California Dept. of Fish and Game 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 Turtles and Lizards of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009. Jones, Lawrence, Rob Lovich, editors. Lizards of the American Southwest: A Photographic Field Guide. Rio Nuevo Publishers, 2009. Smith, Hobart M. Handbook of Lizards, Lizards of the United States and of Canada. Cornell University Press, 1946. Wiens & Reeder (1997 Herpetological Monographs 11: 1-101) Bell (2001 Bulletin of the Maryland Herpetological Society 37(4): 137-142) S. Morey. Western Fence Lizard Family: Phrynosomatidae R022. California Wildlife Habitat Relationships System California Department of Fish and Game. Originally published in Zeiner, D.C., W.F.Laudenslayer, Jr., K.E. Mayer, and M. White, eds. 1988-1990.

Conservation Status
The following status listings come from the Special Animals List which is 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.
Organization	Status Listing
U.S. Endangered Species Act (ESA)	None
California Endangered Species Act (CESA)	None
California Department of Fish and Wildlife	None
Bureau of Land Management	None
USDA Forest Service	None
Natureserve Global Conservation Status Ranks
World Conservation Union - IUCN Red List

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