California Reptiles & Amphibians

Sceloporus occidentalis occidentalis - Northwestern Fence Lizard

Click on a picture for a larger view

Range in California: Red

Click the map for a guide
to the other subspecies.

Adult male, Butte County

Adult female, Sutter County
© Jackson Shedd

Adult male, Del Norte County

Adult male, Sutter County
© Jackson Shedd

Adult male, El Dorado County

Adult female, Solano County

Adult male, Humboldt County

Adult male, Modoc County

Adult male, Merced County

Juvenile, Sierra County

Adult male, Calaveras County

Recent hatchling, August, Maury Island, King County, Washington
© Steven Caldwell

Adult male from Tule Lake, Siskiyou County

Adult female, Siskiyou County

Adult male, Siskiyou mountains, Siskiyou County

Del Norte County, © Alan Barron

Adult male, Solano County

Adult male, Sonoma County

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

Ventral view - Sagebrush Lizard on the right, Fence Lizard on the left. Note the yellow rear thighs on the Fence Lizard.
© Patrick Briggs

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

Adult male, Sutter Buttes, Sutter County.
© Jackson Shedd.
Specimen courtesy of Eric Olson.

Underside of adult male S. occidentalis showing enlarged femoral pores

Adult male with ticks on the side of the head, Sonoma County.

A protein in the blood of the Western Fence Lizard kills the bacterium that causes Lyme disease. Bacteria carried by a tick that bites a lizard are destroyed as the tick ingests the lizard's blood. More Info.

Habitat, Mendocino County

Habitat, El Dorado County

Habitat, Calaveras County

Habitat, Smith River, Del Norte County

Habitat, lava beds, Siskiyou County

Habitat, Shasta County

Habitat, Solono County

Habitat, Siskiyou County

Habitat, Butte County

A California Lizard Travels to Germany

The lizard shown directly above was found in a freight container containing only metal boxes at the BMW plant in Dingolfing / Bavaria / Germany on Oct 17, 2006. The container was shipped from Stockton CA on Sep 14, 2006. The lizard survived a 33 day voyage without food and water. The container was placed most likely on the top deck of the vessel and hence cooled down considerably at night which explains the good condition of the animal upon arrival.

Photos © Jochen Späth
Information: Guntram Deichsel

Many species of plants and animals have been introduced into areas of the planet where they did not naturally evolve. The journey of this lizard illustrates one way animals can spread around the globe: If the lizard was a gravid female who found conditions favorable to her survival once she arrived, laid her eggs, and eventually the offspring began reproducing, or if other lizards arrived at the same location and bred with her, then an established breeding population could develop.

Short Video

This is a Short Video of two Coast Range Fence Lizards, Sceloporus occidentalis bocourtii shot 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 backs form stripes or irregular lines, and sometimes dark blotching may form irregular bands. The belly is light in color.

Males have blue markings on the sides of the belly edged in black, two blue patches on the throat, often connected with a light band, 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

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.

Diurnal. Often seen basking in the sun on rocks, downed logs, trees, fences, and walls. Prefers open sunny areas. 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. Active when temperatures are warm, becomes inactive during periods of extreme heat or cold.

Diet

Eats small 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. Lays 1 - 3 clutches of 3 - 17 eggs usually from April to July. Eggs hatch in about 60 days, usually from July to September.

Range

This subspecies ranges from north and east of the San Francisco Bay Area north thoughout the state into Nevada, Oregon, and Washington. The species 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. Often found on fences, woodpiles, piles of rocks and rocky outcrops, dead and downed trees, wood rat nests, roadsides, and along foot trails.

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 - S. becki. (Wiens & Reeder, 1997) (Bell, 2001)

If it is determined that more of these genetic groups are significantly unique, S. occidentalis could be split into more species and/or the current arrangement of subspecies could be changed. Some experts no longer recognize any subspecies of S. occidentalis pending further studies. (Stebbins 2003) The February 2001 SSAR Circular No. 29, and 2003 update, on which our California State species lists are based, recognizes six subspecies. I will continue to do the same until the new list is published (some time in late 2007 or early 2008) or until I learn of changes based on accepted published work.

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	occidentalis	Northwestern Fence Lizard
Original Description
Sceloporus occidentalis - Baird and Girard, 1852 - Prox. Acad. Nat. Sci. Philadelphia, Vol. 6, p. 175 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 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 bocourtii - Coast Range Fence Lizard Sceloporus occidentalis longipes - Great Basin 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
More Information and References
Natureserve Explorer California Dept. of Fish and Game 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. Smith, Hobart M. Handbook of Lizards, Lizards of the United States and of Canada. Cornell University Press, 1946. Brown et. al. Reptiles of Washington and Oregon. Seattle Audubon Society,1995. Nussbaum, R. A., E. D. Brodie Jr., and R. M. Storm. Amphibians and Reptiles of the Pacific Northwest. Moscow, Idaho: University Press of Idaho, 1983. St. John, Alan D. Reptiles of the Northwest: Alaska to California; Rockies to the Coast. Lone Pine Publishing, 2002. Wiens & Reeder (1997 Herpetological Monographs 11: 1-101) Bell (2001 Bulletin of the Maryland Herpetological Society 37(4): 137-142)

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 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)
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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