Pygmy short-horned lizard (Phrynosoma douglasii)

Small tan colored, fat and oval shaped pygmy short-horned lizard sunning itself on a rock
A pygmy short-horned lizard basks on a rock.
Category: Reptiles
Ecosystems: Shrubsteppe
Vulnerability to climate change (More details)

Moderate

If you see this species, please share your observation using the WDFW wildlife reporting tool or email us at  wildlife.data@dfw.wa.gov. Be sure to include a photo of the species for verification and location (latitude/longitude coordinates) of your observation. 

The population size of pygmy short-horned lizard in Washington is unknown. This species is of conservation concern because its distribution is primarily restricted to the highly altered and fragmented shrubsteppe in eastern Washington. 

Description and Range

Physical description

This species is a medium-sized lizard, rather toad-like in appearance with a blunt snout, round flattened body, short legs, and a short triangular tail. They are commonly called "horny toads," but they are reptiles. From snout to vent (excretory opening), the length ranges between a little over an inch to less than 3 inches. They are cryptic and their coloration tends to match the substrate. The females are significantly larger than the males. 

Ecology and life history

A pygmy short-horned lizard color blends with its habitat
A pygmy short-horned lizard blends with its habitat

In Washington, pygmy short-horned lizards occupy shrubsteppe habitat. They require soil conditions that allow them to burrow below the surface and substrate that is well-drained.  

Adults are active mid-day during spring and fall, but in summer they are inactive during the middle of the day when temperatures are at their maximum.

A study in Washington found that "neonates" (young lizards) feed almost exclusively on ants, while ants made up about 72 percent of the adult diet.

Mating takes place soon after emergence in the spring.

Geographic range

Pygmy short-horned lizards reach the northern extent of their range in Washington and occur primarily in the Columbia Plateau Ecoregion. Abundance varies from site to site. The statewide trend is unknown.

The map illustrates potential range and habitat distribution of this species in Washington. For a map of worldwide distribution and other species' information, check out NatureServe Explorer.

Map of Washington showing boundaries of the pygmy short-horned lizard potential range based on its habitat distribution in 15 counties: Adams, Benton, Chelan, Douglas, Ferry, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Okanogan, Spokane, Walla Walla, and Whitman.
WDFW State Wildlife Action Plan

Climate vulnerability

Sensitivity to climate change

Moderate

Little to no information exists regarding sensitivity of the pygmy horned lizard to climate change. Physiological sensitivity of this species may be low to moderate as it is inactive during cold weather or extended periods of heat, and it is a live-bearer. It appears to exhibit behavioral thermoregulation and burrows when inactive. Its inability to disperse long distances may increase sensitivity of this species. Overall sensitivity of this species is likely driven by its occurrence in shrub-steppe habitats, which are sensitive to altered fire regimes and invasive weeds. Though not as extremely myrmecophagous (ant-eating) as other horned lizards species, it is still preys rather heavily on ants (about three-quarters of the diet); its ability to switch to other prey should its ant prey decline as a result of climate change issues is uncertain.

Confidence: Low

Exposure to climate change

Moderate

  • Increased temperatures
  • Altered fire regimes
  • Increased invasive weeds

Conservation

This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.
A WDFW biologist holds a pygmy short-horned lizard in his hand
A WDFW biologist holds a pygmy short-horned lizard in the Methow Valley

Conservation Threats and Actions Needed

Conservation threats to the pygmy short-horned lizard include conversion of shrubsteppe to agriculture leading to loss and degradation of suitable habitat. Conservation actions needed to address this threat include development and implementation of a strategy to ensure enough suitable shrubsteppe is maintained to support viable populations of this species. Additional threats include a lack of status and distribution information. Research, surveys, and monitoring are needed to address this issue.

Resources