Uta stansburiana

The geographic range extends from central and northeastern California, central and eastern Oregon, central Washington, southwestern Idaho, Utah, and western Colorado southward to the tip of Baja California, northern Sinaloa, and northern Zacatecas, Mexico, including many islands along the Pacific coast of Baja California and in the Gulf of California (Grismer 2002, Stebbins 2003). Elevational range extends from below sea level in desert sinks to about 2,750 m (9,000 feet) (Stebbins 2003).

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) The geographic range extends from central and northeastern California, central and eastern Oregon, central Washington, southwestern Idaho, Utah, and western Colorado southward to the tip of Baja California, northern Sinaloa, and northern Zacatecas, Mexico, including many islands along the Pacific coast of Baja California and in the Gulf of California (Grismer 2002, Stebbins 2003). Elevational range extends from below sea level in desert sinks to about 2,750 meters (9,000 feet) (Stebbins 2003).

DNA data suggest long-established residency on Santa Catalina and San Clemente islands but more recent arrival for the populations on San Nicolas and Santa Cruz Islands, California (Mahoney et al. 2003).

Continent: Middle-America North-America
Distribution: USA (Washington, Oregon, California, Nevada, Utah, W Colorado, Arizona, New Mexico, W Texas),  Mexico (Baja California, Sonora, Chihuahua, NE Durango, Coahuila)  elegans: Mexico (Southern two-thirds of Baja California and on Smiths, Mejía, Angel de la guarda, Isla Partida, Isla Raza, Sal Si Puedes, North San Lorenzo, South San Lorenzo, Tortuga, San Marcos, Ildefonso, East and West Las Galeras, Montserrate, San José, San Francisco, Espíritu Santo, Ballena Island.)
Type locality: La Paz, Baja California.  antiqua: San Lorenzo Norte, San Lorenzo Sur, Salsipuedes Islands, Gulf of California)  martinensis: Mexico (San Martin Island, Baja California.)  stejnegeri: USA (Trans-Pecos Texas, parts of the Texas pahandle, SW Oklahoma, New Mexico, SE Arizona); Mexico: Coahuila, Durango, Nuevo Leon.  stellata: Mexico (San Benitos Island, Baja California.)  stellata: Mexico (San Benito Island, Gulf of California.
Type locality: San Benito Island.)  taylori: Mexico; Holotype: FMNH 100097.

Length: 16 cm

Habitat and Ecology

Systems

• Terrestrial

Comments: Habitats include a wide variety of arid and semiarid situations with scattered bushes and/or scrubby trees; soil may be sandy, gravelly, or rocky; the species is often found in sandy washes with scattered rocks and bushes (Stebbins 2003). Eggs are buried in sandy soil (Nussbaum et al. 1983).

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Comments: Eats insects, spiders, scorpions, mites, ticks, and sowbugs (Stebbins 1985). Diet usually includes many Hymenoptera, Coleoptera, Hemiptera, Orthoptera, and Aranae. Adult males sometimes are cannibalistic on young.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: > 300

Comments: This lizard is represented by a very large number of occurrences or subpopulations.

>1,000,000 individuals

Comments: Total adult population size is unknown but surely exceeds 1,000,000. Where it is most common, the side-blotched lizard often is the most abundant reptile in its habitat. Population density commonly reaches hundreds per acre.

In Colorado, Tinkle (1967) and Tinkle and Woodward (1967) found that home range size is no more than a few hundred square meters, but individuals, especially males, sometimes make long-distance movements of up to a few hundred meters. Distance from the hatching site to the center of the home range was about 6 m in one female and 20-42 m (average 33 m) in four males.

Home range size in western Colorado averaged about 440-610 m2 in males and about 190-225 m2 in females (Tinkle 1967, Waldschmidt 1979, Christian and Waldschmidt 1984) Population density in Colorado was estimated at 25-44 adults/ha (see Hammerson 1982). Density ranged from 11 to 285 individuals/ha in 7 sites in California, Nevada, Oregon, and Washington (mean 60/ha and 78/ha in two consecutive years) (Wilson 1991). May aggregate during hibernation in some areas.

Comments: Activity occurs during daylight hours, mostly March to November in the north, all year in the south.

In most of the range, courtship and mating occur in spring as lizards emerge from hibernation. Reproductive females produce 1-3 clutches of 1-5 eggs in the northern part of the range, 2-7 clutches of 1-8 eggs in the south. Egg laying begins as early as March in the south, by mid-April in Colorado, and extends through July or August in many areas. Females bury eggs in sandy soil. Eggs hatch in late July and August in Colorado, as early as late June in Texas, Nevada, and Idaho. Individuals become sexually mature in 1-2 years (Nussbaum et al. 1983, Hammerson 1999).

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 5
Species With Barcodes: 1

Year Assessed

Assessor/s

Reviewer/s

Justification

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Not intrinsically vulnerable

Population

Population Trend

Global Short Term Trend: Relatively stable (=10% change)

Comments: Extent of occurrence, area of occupancy, number of subpopulations, and population size are large and relatively stable.

Global Long Term Trend: Increase of 10-25% to decline of 30%

Degree of Threat: Low

Comments: No major threats have been identified.

Major Threats

Conservation Actions

Global Protection: Very many (>40) occurrences appropriately protected and managed

Comments: The species occurs in many protected areas, such as national parks, monuments, and wilderness areas.