Conserving the Nature of America

News Release

Fish and Wildlife Service Concludes Flat-Tailed Horned Lizard Not Threatened With Extinction

January 3, 2003


Division of Public Affairs
External Affairs
Telephone: 703-358-2220

The U.S. Fish and Wildlife Service announced today it is withdrawing its 1993 proposed rule to list the flat-tailed horned lizard (Phrynosoma mcallii) as a threatened species under the Endangered Species Act in compliance with a court order.

We have made this determination because threats to the species are not as significant as earlier believed, and current available data do not indicate that the threats to the species and its habitat are likely to endanger the species in the foreseeable future throughout all or a significant portion of its range.

Since seven Federal and State agencies signed a Conservation Agreement in June 1997, a concerted effort has been made to conserve viable populations of flat-tailed horned lizards throughout their range in the United States.

"Although work remains to be done to implement some of the high-priority actions outlined in the Management Strategy, the parties to the 1997 Conservation Agreement have been working in good faith to accomplish their tasks," said Steve Thompson, Manager of the Service’s California-Nevada Operations Office. "We will continue working with our Federal and State partners to conserve the flat-tailed horned lizard in the United States."

Parties to the Conservation Agreement include the Service, Bureau of Land Management, Bureau of Reclamation, U.S. Marine Corps, U.S. Navy, Arizona Game and Fish Department, and the California Department of Parks and Recreation. These agencies agreed to implement a Rangewide Management Strategy which includes taking specific actions to conserve and manage the species and its habitat and establishing five separate management areas. The management areas encompass approximately 35 percent of the remaining flat-tailed horned lizard habitat in the United States.

The flat-tailed horned lizard has a wide, flattened body and a short tail. It can be distinguished from other species of horned lizard by the presence of a dark stripe running down the back, two slender, elongated occipital spines, and the absence of external ear openings. The pale color of the flat-tailed horned lizard closely matches the color of the soils on which it lives. These lizards feed almost exclusively on native ants, consuming about 150-200 ants per day.

Flat-tailed horned lizards are found in the arid valleys and flat lands of the western Sonoran desert. The species’ range includes the Coachella, Imperial and Borrego Valleys in California; portions of southwestern Arizona; and northeastern Baja California and northwestern Sonora, Mexico.

Due to fragmentation of habitat resulting from human-related and natural factors, the species can generally be grouped into four geographically discrete populations in the United States three in California and one in Arizona.

The Coachella Valley population of flat-tailed horned lizards has been identified as the one most threatened by habitat loss and fragmentation. But we do not currently have scientific evidence indicating that this small population is genetically or ecologically significant to the species as a whole.

After a long series of judicial directives, the Service acted to ensure that its determination was based on the best available scientific and commercial information. It opened three separate public comment periods, conducted public hearings on June 19, 2002 in El Centro, California, and asked four independent experts to provide peer review of the 1993 proposed rule.

A notice of the final determination to withdraw the 1993 proposed rule was published in today’s Federal Register. All supporting information used in making this final determination is available for public review, by appointment, at the Carlsbad Fish and Wildlife Office, 6010 Hidden Valley Road, Carlsbad, California 92009. To arrange for an appointment, please contact the office at 760/431-9440.

The U.S. Fish and Wildlife Service is the principal federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 95-million-acre National Wildlife Refuge System, which encompasses 540 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 70 national fish hatcheries, 64 fishery resource offices and 78 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.