Sep. 7--To the motorist passing on Highway 58, California Valley can look like a whole lot of nothing -- brown flatlands nearly devoid of vegetation and inhabited by the occasional cow or raven.

If you're lucky, you can catch sight of a pronghorn antelope or tule elk grazing in the distance.

But to the trained eye of a biologist like John Davis, the valley is full of signs of a vibrant wildlife community living in the state's last remnant of grassland. Many of the animals live underground in this treeless environment, coming out only at night.

Of all the effects the three solar plants will have on the environment of the area, none are as significant as the wildlife impacts.

"Wildlife is the big issue," said San Luis Obispo County Supervisor Jim Patterson, whose district includes the Carrizo Plain.

"The projects cover so much ground," he added. "One of the major characteristics of the Carrizo is the multiple rare and endangered species found there." The Carrizo Plain is the last remnant of grassland in the state.

The solar companies and the state Energy Commission are taking a coordinated look at wildlife issues. The effort has sparked controversy -- the solar companies want some of the results of the study kept confidential because it may identify which lands they must purchase as mitigation and that could drive prices up.

Davis recently led a team of 24 biologists who were surveying a portion of the area that is proposed to be the site of SunPower's California Valley Solar Ranch along the valley's eastern edge.

SunPower hired Davis' employer, URS Corp., a Santa Barbara-based construction consulting firm, to survey the more than three square miles on which the company will build the plant. One day recently, the URS team went looking for blunt-nosed leopard lizards, one of more than 70 rare and endangered animals that live in the area.

None were found -- just as none of the lizards have been found on the other two proposed solar sites. But lots of other rare animals have been seen, including burrowing owls, San Joaquin kit foxes, coast horned lizards, the San Joaquin coachwhip snake and kangaroo rats.

Davis thinks the absence of the lizard is due to the fact that the valley is a marginal habitat for them. This site will be surveyed 12 times before biologists are satisfied that none live there.

"You can't rule them out just because the habitat is marginal," he said. "That's why we do these presence/absence surveys."

The biologists form a line, each person about 100 feet apart. They begin to walk. Occasionally, one stops to examine a hole in the ground or peer through binoculars at the landscape ahead.

The first thing that stands out is that the ground is full of holes.