
Western Fence Lizard blends into granite (Joshua Tree National Park, CA). |
General
Description:
These are medium-sized, rough-scaled lizards. Males have dark blue
patches on the sides of the belly, and the throat is blue. Around Las
Vegas, these can be difficult to tell
from Spiny Lizards (dark bar on the side of the neck) and Sagebrush
Lizards (rusty sides).
Around Las Vegas, Western Fence Lizards occur at higher
elevations such as up on Mt. Charleston where the easiest place to see them is along the Desert
Overlook Trail.
Taxonomy:
Phrynosomatid Lizard Family (Phrynosomatidae). |

Blue throat patch entire (not divided). |
Technical
Description: Western Fence Lizards (Sceloporus occidentalis)
grow to about 7 inches (total length). The dorsal scales are keeled and
spiny, but less so than Spiny
Lizards.
The dorsal coloration ranges from gray to brown to black with dark
blotches or stripes on the back that continue down the tail. Yellow or
orange on
the rear surfaces of the limbs. Scale count between interparietals and
rear of thigh 35 to 51. Complete supraorbital semicircles. Scales on
back of thigh mostly keeled.
In males, the ventral surface is gray with dark blue
patches edged with
black on the sides of the belly. The throat is entirely dark blue. The
dorsal pattern on males is longitudinal stripes. |

Yellow on back of legs. |
In females, the ventral surface is gray with little if
any blue. The dorsal pattern on females is crossbars.
Diet:
Insects and spiders.
Habitat:
In our area,
these are mountain lizards. They are found from the coast to the
mountains, but not in the low desert. They are often found on elevated
perches such as fence posts and rocks, but usually on or near the
ground.
Range:
This species
ranges from central Washington south into Baja California and from the
Pacific Coast east to western Utah. In Nevada, this species occurs
throughout except the southern deserts. |
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Breeding:
Mating
occurs in late spring; as many as 10 eggs per clutch are laid beginning
in July, and hatchlings begin to emerge in August.
Similar
Species:
Sagebrush Lizard:
Size smaller, scales less keeled; ventral surfaces of legs white (not
yellow or orange); armpits, sides of body with rust color.
Spiny
Lizard: Size larger; scales more keeled; dark wedge or
triangle on side of neck.
Comments:
These lizards are often called Blue-bellies or Swifts. |

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Close-up view of keeled scales on the dorsum of a Great Basin Fence Lizard. |

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Male Great Basin Fence Lizard with breeding colors. |

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Dark Great Basin Fence Lizard, dorsal pattern. |

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Same dark Great Basin Fence Lizard as photo above, ventral pattern. |
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Femoral pores and enlarged postanal scales on a Great Basin Fence Lizard. |

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Some Great Basin Fence Lizards have a striped dorsal pattern. |
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A
real Las Vegas lounge lizard, here relaxing (perhaps playing dead) on a
bed of Rock
Spirea up on Mt. Charleston.
This big buck is alive and well; he took off and headed for the hills
shortly after I snapped this photo. |
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Young Great Basin Fence Lizard in Kyle Canyon. |
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Old, black Great Basin Fence Lizard along the Desert Overlook Trail. |