The white pickup bounces over the irregular terrain, and blasts through large tumbleweeds blocking its path.

Navy jets roar overhead, as the truck drives farther into the old motocross track on Lemoore Naval Air Station.

"I have taken people out here who have worked here their whole federal career and had no idea that this was even part of the base," said John Crane.

The Navy veteran and natural resource specialist is the caretaker of the track that now makes up the habitat of the Fresno kangaroo rat.

Under his watchful eye, the endangered species is free to hop, dig and burrow on the 100 acres of land owned by the Department of the Navy.

Scattered throughout the track area are a few cleared trails and one acre plots without any vegetation growing on it. Wooden planks sit in the middle of the plots.

The plots have been specially designed to suit and protect the endangered rodent, which needs a certain amount of clear, open ground to move around. The rat measures only about the size of a chicken egg, with a tail about one and a half times its body length, Crane said.

In the early 1990s, the U.S. Fish and Wildlife Service ordered the motocross track closed to human activity after someone went in with a tractor and doctored the trails in 1992, without authorization from anyone, said Crane.

Sixty percent of the known kangaroo rat burrows were destroyed by the tractor, Crane said.

Before the tractor incident, the kangaroo rats weren't disturbed by the motocross vehicles.

"The motocross activities were a good thing because it controlled excess vegetation and the motorcycle activities kept loose, stirred up dirt at the end of the track, which the rats used for burrows," Crane said.

The track, now nicknamed "Tumbleweed Park," is still closed to human activity and dedicated entirely to the Fresno kangaroo rat. The refuge has a fence around the perimeter and a locked gate. A sign on the gate warns "Endangered Species Habitat. This area is off limits."

The U.S. Fish and Wildlife Service has pretty much stayed out of the day to day management of Crane's efforts, since Lemoore NAS completed a natural species plan that details how Lemoore will manage its natural resources.

One thing for sure, the kangaroo rat's numbers are increasing.

"At one time it was as low as between 35 and 50, now it's between 150 and 200 animals," Crane said.

"If the population of the kangaroo rat is increasing, it sounds like they're doing a pretty decent job of helping the species," said Al Donner, assistant field supervisor with the U.S. Fish and Wildlife Service's Sacramento office.

The government's efforts to protect an endangered species may determine whether that species survives or not, said John Buckley, executive director of Central Sierra Environmental Resource Center.

"When the government works to protect a species that is on the brink of disappearing, that action may mean the difference at the tipping point of that species either surviving or being lost forever," said Buckley.

Crane is also responsible for managing the farming operations around the base.

The Department of the Navy leases roughly 13,000 acres of the 18,000-acre base to farmers. The farmland serves as an easement around the base to prevent municipal development, Crane said. Having the easement reduces the impact of jet noise on residential development.

The greenbelt around the airfield protects the jets from foreign object damage, Crane said. If the land weren't used, there would be a tumbleweed and dust problem, which would create a hazard on the airfield.

Those who farm on base are also required to take measures so land doesn't expire.

"We require them to add certain soil amendments during the terms of their lease to maintain soil fertility," Crane said.

Another species Crane protects on base is the burrowing owl. This species is listed statewide as "a species of concern."

"We have what is considered to be the largest breeding population of burrowing owls in the Central Valley," Crane said.

The burrowing owl stands about nine inches high and lives in burrows in the ground.

To help protect the burrowing owls, Crane instituted a nestbox program. He buried 6-by-4 foot boxes in the ground for the owls, to protect them from coyotes and feral dogs.

Prior to having the nest boxes, the owls were living in arresting gear housing on the airfield, culverts and exposed electrical conduits.

The reporter can be reached at 582-0471, ext. 3052

(Saturday, Feb. 24, 2007)