Flat-tailed Horned Lizard (Phrynosoma mcallii)

Listing Status

Basking adult FTHL, El Centro, CA

CA State Species of Special Concern (CDFW)

**Candidate Species for CDFW State Endangered**

Suitable Habitat

The FTHL is found within San Diego, Riverside, and Imperial Counties in sandy flats and valleys with sparse vegetation consisting of creosote (Larrea tridentata) and/or white bursage (Ambrosia dumosa). Fine sand is imperative as the burrow within the sand to avoid high temperatures. They require areas with healthy harvester ant populations, as that is their main food source. 

Survey Requirements

Surveys should be conducted from April through September during ambient temperatures between 75-100 F. For project impact areas less than 9 hectares, a minimum of four 1-hour presence absence surveys covering 1 hectare should be conducted where one survey plot is centered on the project site.  One must be authorized by CDFW to conduct surveys and handle/relocated FTHL. Prior to a survey round, a survey proposal should be approved by either CDFW and/or by the state or federal agency that manages the surveyed land (i.e. BLM). 

Conservation Status

FTHL populations are threatened due to habitat loss and fragmentation due to agriculture as well as on and off-road vehicular activities. The FTHL was approved as a candidate species for listing as an endangered species by CDFW on February 12, 2015 and on February 24, 2015 it was announced. The public comment period is currently open and ends on September 14, 2015. A determination announcing if the proposed listing is warranted is expected to be published by February 24, 2016.


CalHerps Species Profile

Horned Lizard Conservation Society

Arizona USFWS Species Documents

FTHL Rangewide Management Strategy (2003)

Center for Biological Diversity Petition to List the FTHL (2014)


Flat-tailed Horned Lizard Interagency Coordinating Committee. 2003. Flat-tailed horned lizard rangewide management strategy, 2003 revision. 78 pp. plus appendices.