This species occurs in the northwestern United States, and formerly in southwestern Canada. It ranges from southern British Columbia (where it is apparently extirpated; Powell and Russell 1998) south to northeastern California, northern Nevada, and southern Idaho (Zamudio et al. 1997, Stebbins 2003); eastern and southern range limits have not been precisely determined; there is an old record from extreme southwestern Montana, where current status is unknown (St. John 2002, Werner et al. 2004). Its elevational range extends from around 300 to 1,830 m (1,000 to 6,000 feet) (Stebbins 2003).

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Absent

Confidence: Confident

Type of Residency: Year-round

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)) Southern British Columbia (apparently extirpated; Powell and Russell 1998) south to northeastern California, northern Nevada, and southern Idaho (Zamudio et al. 1997, Stebbins 2003); eastern and southern range limits have not been precisely determined; old record from extreme southwestern Montana, where current status is unknown (St. John 2002, Werner et al. 2004). Elevational range extends from around 300 to 1,830 meters (1,000-6,000 feet) (Stebbins 2003).

Length: 15 cm

Syntype for Phrynosoma douglasii
Catalog Number: USNM 11945
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1878
Locality: No Further Locality Data, Oregon, United States, North America

Paratype for Phrynosoma douglasii
Catalog Number: USNM 23995
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1896
Locality: Durango, Mexico

Paratype for Phrynosoma douglasii
Catalog Number: USNM 23996
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1896
Locality: Durango, Mexico

Paratype for Phrynosoma douglasii
Catalog Number: USNM 23994
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1896
Locality: Durango, Mexico

Holotype for Phrynosoma douglasii
Catalog Number: USNM 23993
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1896
Locality: Durango, Mexico

Syntype for Phrynosoma douglasii
Catalog Number: USNM 9199
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: Fort Steilacoom, Pierce, Washington, United States, North America

Syntype for Phrynosoma douglasii
Catalog Number: USNM 11473
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1878
Locality: Deschutes River, Locality In Multiple Counties, Oregon, United States, North America

Syntype for Phrynosoma douglasii
Catalog Number: USNM 10918
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Year Collected: 1881
Locality: Fort Walla Walla, Walla Walla, Washington, United States, North America

Habitat and Ecology

Systems

• Terrestrial

Comments: This lizard ranges from semiarid plains to high mountains: sagebrush, bunchgrass, pinyon-juniper woodland, openly spaced pines (Stebbins 2003). Usually it occurs in open, shrubby, or openly wooded areas with sparse vegetation at ground level. Soil may vary from rocky to sandy. When not active on the surface, the lizards burrow into the soil or occupy rodent burrows.

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: Diet consists primarily of ants and other insects.

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

Estimated Number of Occurrences: 81 - 300

Comments: This species is represented by many occurrences scatttered throughout its historical range.

10,000 - 1,000,000 individuals

Comments: Total adult population size is unknown but surely exceeds 10,000.

Comments: Inactive during cold weather; also avoids extreme heat.

Gives birth to 3-15 young, mainly August to mid-September (Brown et al. 1995). Sexually mature in 2 or more years (Nussbaum et al. 1983).

Canada

Rounded National Status Rank: NX - Presumed Extirpated

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Moderately vulnerable

Population

Population Trend

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

Comments: Extent of occurrence, area of occupancy, and population size appear to be relatively stable.

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

Major Threats

Comments: No major threats have been identified.

Conservation Actions

Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed

Comments: This species occurs in many protected areas.

Comments: Zamudio et al. (1997) examined mtDNA variation in short-horned lizards throughout western North America and concluded that the Pacific Northwest segment of the population should be recognized as a species (P. douglasii) distinct from the species (P. hernandesi) represented in the remainder of the range. In addition, there was no support for the recognition of any of the nominal subspecies; thus each species is best regarded as monotypic. See Hammerson and Smith (1991) for information on the correct spelling of the specific name (formerly douglassii). The specific name is here spelled with a double-i ending, since that is how it was rendered in the original description. The common name used here follows Sherbrooke (2003).


Reeder and Montanucci (2001) examined phylogenetic relationships of horned lizards (Phrynosoma) based on mtDNA and morphology.