fter a rainstorm, you'll find T'Shaka Touré peering into a series of buckets placed at ground level throughout the Irvine Ranch Land Reserve. From the buckets - called "pitfall traps" - he and fellow researchers extract a potpourri of live frogs, toads, lizards and other critters. Next they check cylindrical wire traps for snakes. The animals are documented, sometimes tagged for re-identification, and then gently placed on the ground to crawl, hop or slither away.

T'Shaka is a research ecologist with the U.S. Geological Survey, Biological Resources Division, the science agency of the Department of the Interior. For the past two years, he has conducted baseline surveys of the reserve's amphibian and reptile populations. "These studies give us the fundamental information that allows us to ask questions about specific species: How many are there? What is the status of their habitat? What steps can we take to help them survive?" T'Shaka says. "They give us a clear picture of what's occurring, and let us see if there are windows of opportunity for stepping in and helping certain species."

For example, T'Shaka and fellow USGS researchers are working to protect native, locally rare Western pond turtles, which have been turning up in local culverts that provide a constant water source. But the turtles can't lay eggs and reproduce on the culverts' cement bottoms, so T'Shaka - a wetlands habitat expert - and colleagues are identifying areas in Limestone and Fremont canyons where the turtles' natural environments could be recreated. In another project, they're exploring long-term strategies to protect the horned lizard population. The spiky little critters are being displaced in part by non-native Argentine ants, which devour harvester ants, the horned lizard's dietary staple.

When T'Shaka told his former colleagues at the Smithsonian Institution - where he worked as a biologist - that he was headed for Orange County to monitor amphibian and reptile populations, their response was bemusement.

"The big joke was, 'Oh, T'Shaka, you're going to go monitor extinction,' " he recalls. Their assumption: Orange County was so urbanized, there were few or no animals left to monitor. But T'Shaka is enjoying the last laugh. To date, 35 species of amphibians and reptiles - including rare and locally threatened species - have been found on the reserve, out of the 43 species known to exist in all of Orange County.