Great Basin Fence Lizard (Sceloporus occidentalis biseriatus)
aka Western Fence Lizard (Sceloporus occidentalis)
Lizards Around Las Vegas, Wildlife Around Las Vegas
 

Western Fence Lizard (Sceloporus occidentalis biseriatus)
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).

Western Fence Lizard (Sceloporus occidentalis biseriatus)
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.

Western Fence Lizard (Sceloporus occidentalis biseriatus)
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.

Western Fence Lizard (Sceloporus occidentalis biseriatus)

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.

Western Fence Lizard (Sceloporus occidentalis biseriatus)
Close-up view of keeled scales on the dorsum of a Great Basin Fence Lizard.
Western Fence Lizard (Sceloporus occidentalis biseriatus)
Male Great Basin Fence Lizard with breeding colors.
Western Fence Lizard (Sceloporus occidentalis biseriatus)
Dark Great Basin Fence Lizard, dorsal pattern.
Western Fence Lizard (Sceloporus occidentalis biseriatus)
Same dark Great Basin Fence Lizard as photo above, ventral pattern.
Western Fence Lizard (Sceloporus occidentalis biseriatus) Femoral pores and enlarged postanal scales on a Great Basin Fence Lizard.
Western Fence Lizard (Sceloporus occidentalis biseriatus)
Some Great Basin Fence Lizards have a striped dorsal pattern.
Western Fence Lizard (Sceloporus occidentalis biseriatus) 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.
Western Fence Lizard (Sceloporus occidentalis) Young Great Basin Fence Lizard in Kyle Canyon.
Western Fence Lizard (Sceloporus occidentalis) Old, black Great Basin Fence Lizard along the Desert Overlook Trail.

 
Note: All distances, elevations, and other facts are approximate.
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