A cocktail of threats including rising temperatures, fire-suppression projects and predation by pet cats is forcing a rare species of flying squirrel in the San Bernardino Mountains to retreat to ever higher elevations in search of suitable habitat.
Fearing the San Bernardino flying squirrel population may eventually run out of room in its last mountain refuge, the Center for Biological Diversity on Tuesday filed a lawsuit against federal wildlife authorities for failing to list it as an endangered species.
"The federal government needs to act before these unique animals disappear forever," Shaye Wolf, the center's climate science director, said.
In 2010, the center petitioned to have the squirrel protected under the U.S. Endangered Species Act. In 2012, the U.S. Fish and Wildlife Service determined that the species may warrant federal protection.
"The Service is now nearly three years overdue in making the required 12-month finding to decide whether protection will be granted," said Wolf, whose organization filed the lawsuit in the U.S. District Court for the District of Columbia.
The nocturnal, truffle-eating flying squirrel was historically found in the sloping forests of Southern California's San Bernardino and San Jacinto mountains. However, there have been no confirmed sightings in the San Jacintos in more than a century, and a recent survey found no tenants in the range's remote old-growth forests.
The fate of the flying squirrel in the San Jacinto Mountains remains veiled in mystery, scientists say.
The remaining population is seeing its forest habitat move upslope, and as temperatures increase, drier conditions threaten its truffle supply, which thrives in wet, cool conditions, Wolf said.
Compounding problems, fuel reduction projects are removing canopy cover and snags that flying squirrels rely on for nesting and foraging, and urban development is gobbling up remaining habitat and increasing predation by domestic cats.
The flying squirrel, which uses furred membrane that extends from wrist to ankle to glide more than 300 feet between trees, is one of 10 species across the country that the center is prioritizing for federal protection this fiscal year.
The others include the Alexander Archipelago wolf from Alaska; the Ichetucknee siltsnail from Florida; the black-backed woodpecker from California and South Dakota; Kirtland's snake from the Midwest, and two fish, a mussel and a crayfish from the southeastern United States.