California's small scaly lizards
This discussion of California's small scaly lizards begins with the common "blue-bellies" in the genus Sceloporus, and particularly the widespread Western Fence Lizard S. occidentalis (above, left and below). Males (above & left) have blue bellies (and often blue throats) and can be speckled with blue above. Females can have blue bellies but many females and youngsters (below) do not. Their upperpart color varies from quite dark (above & left) to a camouflage pattern of brown and cream blotches (below).
These are small lizards typically just 4-7 inches in length, with males larger than females and youngsters. Western Fence Lizards occur in a wide variety of habitats from chaparral and riparian habitats along the coast to Great Basin washes to Sierran rocky slopes. They are usually quite common where they are present [absent only from the low deserts]. While they can climb trees, they are most often found on the ground or in brush piles or rocks.
There is a lot of uncertainty about geographic variation and subspecies in Western Fence Lizard. My old Stebbins' guide (1985) showed four subspecies: Northwestern S. o. occidentalis [all of n. CA west of the Sierran-Cascades divide and south in the coast ranges through Monterey Co.], Great Basin S. o. biseriatus [northeast CA plus the high deserts and coast ranges of s. CA], Sierra S. o. taylori [high Sierra from Tuolumne R. drainage to Sequoia Nat'l Park], and Island S. o. becki [Santa Cruz, Santa Rosa, and San Miguel Is.]. The new Stebbins' guide (2003) has just two races: the nominate widespread lizard and the high Sierran populations. Crother et al. (2001) lists all the old Stebbins' races plus more: Coast Range S. o. bocourtii [presumably the San Francisco Bay/Monterey Co. lizards], while S. o. biseriatus becomes the San Joaquin Fence Lizard and the Great Basin populations take the name S. o. longipes. But Crother et al. (2001) also state that "a study in progress ... indicates that at least some of the subspecies ... are artificial groups" while another paper "suggested that Sceloporus occidentalis becki [Island Fence Lizard] should probably be recognized as a species on the basis of diagnosability and allopatry relative to other S. occidentalis."

For what it's worth, the photos here show three widely separated populations: the top photo was taken at high elevation in Sequoia Nat'l Park, Tulare Co., and thus is apparently S. o. taylori, the Sierra Fence Lizard. This is the largest subspecies with males reaching over 8 inches. The dark-backed lizard above left (on the rock with orange patches) is from extreme southeast Mono County and would be among the Great Basin populations under the old terminology. The more patterned youngster (above right) and the male (below two photos) are from the coastal populations in Monterey County.

I once witnessed a very unexpected and impressive display in a Western Fence Lizard at Andrew Molera State Park, Monterey County (two right shots). The blue-bellied but white-throated male began a series of push-ups, and at the height of each he flared out his vivid blue belly and extended his gular flap. While I often see males doing "push-ups," I've never seen the gular flap display before or since.

Note how "scaly" all the various Western Fence Lizards appear. They look "rough" from above. The Stebbins' guides (1966, 1985, 2003) all emphasize the yellow or orange color on the back of the legs, but I find this feature very hard to see.

Western Fence Lizards eat mostly insects and spiders. They lay clutches of 3-17 eggs (sometimes multiple broods) between April and July.

A closely related Sceloporus is Common Sagebrush Lizard S. graciosus (left & right). It has three subspecies [Western, Northern, Southern) but both of those shown here are from the Western, nominate group. This lizard overlaps with Western Fence Lizard in places but generally occurs at higher elevations. Indeed, both of these photos are about as high as one can go in Humboldt Co. (left; Horse Mt.) and Monterey Co. (right; Cone Peak].

Identification can be complicated but in the height of the breeding season (June-Aug) many Sagebrush Lizards have orange washes to the throat or body (above right). At all times they look less "rough" than Fence Lizards, they generally lack the yellow or orange on back of limbs, and they often have black bar at the shoulder.

The final of the trio of widespread, small, scaly lizards is Side-blotched Lizard Uta stansburiana (right). In California it is often the commonest small lizard in the deserts, but its range also extends in arid habits up the coast ranges to central California. In the south it is active all year among rock, sand, or hardpan with small scattered bushes. It is not nearly as "scaly" as the other two widespread species; they are, of course, Sceloporus while Side-blotched is in the genus Uta. The scales are small and smooth, giving the lizard a "smooth" rather than "rough" appearance. Most individuals have a more-or-less conspicuous black blotch on each side of the chest, behind the forelimb. It can look "stripy" somewhat, and is often washed with a bit or pale orange along the sides. Ground color varies widely with its habitat it can be blotched or speckled (like the one here, taken in the Carrizo Plain, San Luis Obispo Co.) or unpatterned. Stebbins (1985, 2003) lists no subspecies at all, but Crother et al. (2001) lists four [Western, Nevada, Northern, Eastern]. Side-blotched Lizards are not necessarily the closest relatives to Sceloporus, but I include them together with Fence and Sagebrush lizards because I have trouble with these small lizards.

Side-blotched Lizards in the Colorado and Mojave deserts may lay up to 8 clutches of 5-6 eggs each between Feb-June each year. This is just one reason these lizards are often abundant. They are also an important prey item for other predators, and this helps keep their overall numbers in check (Sanborn 1994). 

In the three photos below, I compare these three small lizards side-by-side, choosing those photos in my collection with patterns and poses most similar to each other:

Western Fence Lizard
Monterey Co.
Sagebrush Lizard
Monterey Co.
Side-blotched Lizard
San Diego Co.

There are many on-line resources for lizards. My favorites are:

A fabulous resource for southern California is Sherburn Sanborn's (1994) Lizard-Watching Guide.

Literature cited:

Crother, B.I., chair. 2001. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Committee of Standard English and Scientific Names, Society for the Study of Amphibians and Reptiles, Herpetological Circular 29 (as supplemented in Herp. Review 32: 152-153).

Sanborn, S.R. 1994. The Lizard-Watching Guide. Lorraine Press, Salt Lake City, UT.

Stebbins, R.C. 1966. A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin, Boston.

Stebbins, R.C. 1985. A Field Guide to Western Reptiles and Amphibians. 2d ed. Houghton Mifflin, Boston.

Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians. 3d ed. Houghton Mifflin, Boston.

PHOTOS: All photos © 2003 Don Roberson, all rights reserved. These are the specifics: TOP




Page created 4 July 2003