Environmentalists are asking the state to list a rare Southern California lizard as Endangered, citing decades of federal inaction on the dwindling species.
The Center for Biological Diversity (CBD) petitioned the California Fish and Game Commission Monday to list the flat-tailed horned lizard (Phrynosoma mcallii) as Endangered under the California Endangered Species Act. The group says that repeated refusal by the U.S. Fish and Wildlife Service to protect the species under the federal Endangered Species Act (ESA) means the lizard isn't sufficiently protected from off-road vehicles, energy development, and other human activity throughout its habitat.
Though USFWS proposed to list flat-tails as a threatened species as early as 1982, the agency has declined to list the lizard four times since then. The agency's main rationale: flat-tailed horned lizards are hard to find and thus hard to count, and USFWS says that that means we don't know how many are actually out there, and therefore we don't know whether their numbers are dwindling.
"Because there are no protections for this imperiled species under the Federal Endangered Species Act and the current conservation actions are inadequate to protect the species and its habitat in California," reads the CBD petition to the Fish and Game Commission, "petitioners seek to list the FTHL [flat-tailed horned lizard] as endangered under California's Endangered Species Act."
Flat-tailed horned lizards are indeed hard to spot: their coloration blends well with the sandy soils they tend to frequent, and when they spot a potential threat they tend to freeze in place. Even experienced herpetologists specializing in horned lizards have trouble finding flat-tailed horned lizards.
That fact means that it's hard to nail down what constitutes the species' historic range, given that no surveys were done for the lizards prior to the massive alteration of the lizards' likely stronghold in the Imperial Valley when agriculture got started there in the early Twentieth Century.
Nonetheless, what estimates we do have of the species' lost habitat in California range upwards of fifty percent. Sightings of the lizards have indeed been dropping across much of the species' range, especially in the development-addicted Coachella Valley where much of the suitable habitat for the species has been converted to agriculture or urban development.
The lizards, which generally measure two to four inches from their snouts to the bases of their tails, are also threatened by invasive species encroaching on their habitat. Chief among those threatening invasives are Sahara mustard, which colonizes the sandy soils the lizards prefer, and Argentine ants, which displace the native harvester ant species that make up the lizard's primary food source.
In lieu of listing under the federal Endangered Species Act, state and federal agencies signed a conservation agreement in 1997 to manage threats to flat-tailed horned lizards from human activity. The existence of that agreement was cited by USFWS in 2011 as part of its rationale for denying the lizard protected status under ESA.
But CBD staff point out that that agreement hasn't prevented destructive inroads into the lizard's shrinking habitat, citing developments like the 100-acre Ocotillo Sol solar project near El Centro, and the recent reopening of more than 60 square miles of the Algodones Dunes to off-road vehicle use.
"This charming little lizard used to be fairly common in parts of the Sonoran Desert, but it's been declining throughout its range in recent years," said CBD biologist Ileene Anderson. "A 1997 voluntary conservation agreement was supposed to help the lizard recover but clearly it isn't working. State protection will give this lizard a fighting chance at survival."