Flat Tailed Horned Lizard Conservation Efforts

Lead CDFW biologist: Jack Crayon

Management of Flat Tailed Horned Lizard (Phrynosoma mcallii)

The Flat-tailed Horned Lizard (Phrynosoma mcallii) has the most limited distribution of any horned lizard species in the U.S. It is found in the Colorado Desert in California, Arizona and Mexico. Its California range is mostly contained in the Imperial and Coachella Valleys in CDFW's Inland Deserts Region, with some habitat in Eastern San Diego County.

Numerous failed attempts to list the species at both the Federal and State level led to the development of a Conservation Agreement in 1997 among state and federal parties that oversee Flat-tailed Horned Lizard (FTHL) habitat. CDFW joined the Department of Parks and Recreation, Arizona Department of Game and Fish, and several Department of Defense and Interior agencies as signatory parties to the Agreement.

The purpose of the Agreement is to facilitate the development and implementation of a link opens in new tab or window Rangewide Management Strategy (PDF) (RMS) for the species. The RMS provides a framework for securing and managing sufficient habitat to maintain several self-sustaining populations of the FTHL throughout the species' range. A central component of the RMS is the designation of five Management Areas and a Research Area for the lizard. The Management Areas protect close to 500,000 acres of FTHL habitat.

The RMS is overseen by a Management Oversight Group, on which Eddy Konno represents CDFW. Jack Crayon represents CDFW the on the Interagency Coordinating Committee, which provides technical guidance to the Managers Oversight Group. The member agencies sponsor annual training for FTHL monitors. Region 6 provides Letters of Concurrence to trainees, which allow them to perform the work of a biological monitor according to protocols in the RMS, and as part of required mitigation during construction.

The flat-tailed horned lizard habitat is also being monitored and managed in the Coachella Valley and along the Lower Colorado River under separate habitat conservation plans:

  1. Coachella Valley Multi-Species Habitat Conservation Plan
  2. link opens in new tab or windowLower Colorado River Multi-Species Conservation Program
The links provide general information about the two conservation programs. More specific conservation information about the flat-tailed horned lizard is linked below.

Additional Information on Flat Tailed Horned Lizard