Western Fence Lizard

Although California is the heart of the range of this lizard, it is also found in eastern and southwestern Oregon (some populations are found even north of Seattle, Washington), as well as in the Columbia River Gorge, southwestern Idaho, Nevada, western Utah, northwestern Baja California, New Mexico, Arizona, and some of the islands off the coast of both California and Baja California. There is also an isolated population in the Northwestern Tualatin Valley, around Henry Hagg Lake. The western fence lizard occupies a variety of habitats. It is found in grassland, broken chaparral, sagebrush, woodland, coniferous forest, and farmland, and occupies elevations from sea level to 10,800 ft. They generally avoid the harsh desert and are often found near water. In California, the western fence lizard is found in most territories apart from deserts or densely forested locations. According to predictions by the California Department of Fish and Wildlife, most of California except for the San Joaquin Valley and South Eastern California are suitable habitats for the western fence lizard. In the habitats, the western fence lizard functions as an important food source for many vertebrates including snakes and predatory birds. As of now, the western fence lizard is listed as unprotected, and no conservation restrictions apply.

These lizards are diurnal, and are commonly seen basking on paths, rocks, and fence posts, and other suitable sunny locations. Some nocturnal activities are noted during warm periods, the length of which varies geographically but mostly falls in spring and summer. They can change color from light grey or tan to nearly jet black for the purpose of thermoregulation while basking. S. occidentalis goes through a period of brumation during the winter. The length of time and when they emerge varies depending on climate. During mating seasons, adult males will defend a home that ranges up to 7.5 meters in radius through posturing and combat, displaying for both females and rival males with their distinctive "push-ups". On occasion, they can be seen fighting. The western fence lizard feeds almost exclusively on terrestrial invertebrates. The main source of food is insects, and the western fence lizard is less frequently observed to feed on spiders, isopods, centipedes, ticks, scorpions, and sometimes even other western fence lizards. The sagebrush lizard has a similar geological distribution compared with the western fence lizard, and some competition for food may occur between the two species. However, the two species can co-occur without reducing each other’s population size since they have different food sources and avoid each other on a local scale.