Sceloporus occidentalis

The scales on the back are fairly large, keeled, and pointed. Coloration is highly variable, but often the back is gray, brown, or black, with a series of wavy dark and light bands across the back or a row of somewhat V-shaped dark blotches along each side of the back. ; rear of thigh yellow or orange; scales on rear of thigh mostly keeled; up to 3.9 inches (9.9 cm) snout-vent length. Breeding males have a blue patch on the throat (sometimes partially divided), a blue black-edged patch on each side of the belly (in some areas there may be a single large blue patch on the belly), sometimes blue or greenish scales on the back, a pair of enlarged scales behind the vent, and two swellings from hemipenes (copulatory organs) on the underside of the tail base. Breeding females and small young lack blue scales on the back, and the blue markings on the underside are faint or absent; they also lack enlarged scales behind the vent and have no swellings at the tail base.

This lizard occupies various habitats, including grassland, sagebrush, woodland, open coniferous forest, rocky canyons, talus slopes, fence rows, etc. (Stebbins 2003). This species is not found in severe desert areas, but it comes close on mountain slopes (Stebbins 2003). Usually it is on the ground or on low perches (e.g., logs, fences), but sometimes climbs well up into taller bushes or trees. Eggs are buried in loose soil.

Adult males defend home range during breeding season. Seasonal home range generally much less than 0.01 ha in central California (Davis and Ford 1983). Predators: predatory birds and snakes.

When individuals on tree trunks are approached closely, they often move to the other side of the trunk.

Courtship and mating generally occur in spring. Egg laying extends from April or May to June or July in most areas. Eggs are buried in loose soil or secluded in old logs or under rocks. Clutch size in different areas ranges from 3 to 17; clutch size tends to increase with female size, latitude, and elevation. Eggs hatch in about 2 months, mostly in August or September in many areas. Individuals first breed in the spring of their second year (Nussbaum et al. 1983, Stebbins 1985).