Environmental groups on Thursday petitioned the U.S. Fish and Wildlife Service to protect even more habitat for the endangered San Joaquin Kit Fox, including in Kern County.

Approval could add barriers for development in the public and private oil, water and farming sectors here, county officials said.

Federal and state law already protect kit foxes, but the petition asks Fish and Wildlife to identify parts of the Valley as "critical habitat." Upon designation, the feds would have to make sure projects don't "destroy or adversely modify its critical habitat," the petition states.

"(Kit foxes are) heading on a downward spiral toward extinction," said Ileene Anderson, a biologist and public lands desert director with the Center for Biological Diversity, a nonprofit conservation group that seeks protection of endangered species. "The notion is 'Let's try to do something about that and give them areas so they can continue to reproduce.'"

Los Padres Forest Watch, a nonprofit that protects the neighboring Los Padres National Forest, partnered on the petition. The groups identify a wide stretch of Valley land that should be protected further. It includes parts where kit foxes need sufficient land to prevent inbreeding, areas where they're reproducing well but in small numbers, and areas where they're thriving and therefore, should continue to be protected, Anderson said.

The Kern areas identified are mostly in western and central Kern, maps show, and are home to oil business, water agencies and others.

Typically, when an area is classified as a critical habitat, building on the land becomes more of a challenge as plans need to be approved by federal and state regulators. Developers may need to take extra steps, possibly moving projects where kit foxes don't roam, said Ted James, county development service director.

"There is heightened scrutiny of projects when it's under critical habitat," James said. "They may want to see if the projects can't be redirected someplace else."

Kern County already has a conservation plan in the works that is about a year from completion, James said. If the kit fox petition is approved, Kern's plans might need to be reapproached.

Some solar projects in San Luis Obispo County are cutting into kit fox habitat, Anderson said. Here in Kern, oil and gas development in western parts could be interfering on their grounds, she said.

It's unknown how many San Joaquin kit foxes -- the smallest member of the fox family -- are in the area. Carrizo Plain, just west of Taft in San Luis Obispo County, is thought to have the largest population -- between 251 and 610, according to 2000 estimates by the federal department.

Under current law, harming a kit fox or destroying its den is a misdemeanor and may result in a fine and jail time.

They reside throughout Kern County, but have made homes near college campuses, malls and golf courses in Bakersfield. If something isn't done to protect them, kit foxes could be extinct in the next 20 years, Anderson said.

The petitioners are now waiting for the federal department to respond. Critical habitat designation could take up to a year.