WASHINGTON— The Center for Biological Diversity filed a petition today seeking Endangered Species Act protection for imperiled Sacramento Mountains checkerspot butterflies. The orange-and-black checkered butterflies are found only in high-elevation meadows around the village of Cloudcroft, in the Lincoln National Forest in southern New Mexico.

The Sacramento Mountains checkerspot butterfly has been declining since the Forest Service began formal surveys in 1999. By 2012 the butterfly occupied half the number of monitored sites it had formerly occupied, and it has continued to decline precipitously. Today it is virtually undetected throughout its range, leading the Forest Service to conclude that it is likely the most endangered butterfly in the United States, with a non-trivial probability of imminent extinction.

In response to a 1999 petition from the Center, the U.S. Fish and Wildlife Service proposed to list the Sacramento Mountains checkerspot butterfly as endangered due to habitat loss, fragmentation, degradation, drought, wildfire and overcollection. Unfortunately, the Service withdrew that proposal in 2004 based on a voluntary conservation plan that lacked real teeth; it denied a subsequent listing petition in 2009, allowing threats to the butterfly to continue unabated.

“The sharp decline of the Sacramento Mountains checkerspot butterfly is alarming,” said Dr. Tara Cornelisse, an entomologist and senior scientist at the Center. “Clearly the U.S. Fish and Wildlife Service’s two-decade refusal to protect this pretty butterfly has contributed to its demise. We hope it’s not too late to save it.”

The situation described in the Service’s 2001 listing proposal was so dire that the agency recommended endangered status and the designation of all suitable habitats, including unoccupied habitats and dispersal corridors, as critical habitat.

Over the past 20 years, the Sacramento Mountains checkerspot butterfly has continued to decline. No caterpillars and only a handful of adults have been observed in the past three years, despite expanded search efforts. The butterfly is still threatened by habitat loss, fragmentation and degradation via livestock grazing, motorized recreation, invasive species, fire suppression and climate change.

“By reversing their own conclusions and ignoring this butterfly’s plight, the Fish and Wildlife Service has failed to protect this imperiled species,” said Cornelisse. “The Endangered Species Act works, but only if species are protected in the first place. Too often the fear of political backlash influences the agency’s decisions and keeps it from doing its job to save species.”

To give the Sacramento Mountains checkerspot butterfly a chance at survival, the Fish and Wildlife Service must list it as endangered under the Endangered Species Act and designate critical habitat immediately.