General Description: Great Basin Fence Lizards (Sceloporus occidentalis longipes) 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 Desert Spiny Lizards (dark bar on the side of the neck) and Sagebrush Lizards (rusty sides).

Around Las Vegas, Great Basin 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).

Technical Description: Great Basin Fence Lizards grow to about 7 inches (total length). The dorsal scales are keeled and spiny, but less so than in 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. Males may darken with age.

In females, the ventral surface is gray with little if any blue. The dorsal pattern on females is crossbars. Juveniles of both genders look like adult females.

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 the state except not in the lower-elevation deserts.

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.

Desert 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.

Many species of lizards can darken their scales when cold to absorb more solar radiation and warm up more quickly. When warn, they can lighten their scales to reflect more solar radiation to stay cooler.