RENO — A thumbnail-size butterfly found only in northwestern Nevada and northeastern California was given permanent protection Wednesday under the Endangered Species Act.
The listing published in the Federal Register makes permanent an emergency action taken in November by the U.S. Fish and Wildlife Service to protect the Carson wandering skipper.
"We know of only two populations of the skipper, and both are threatened with habitat destruction," said Bob Williams, supervisor of the Fish and Wildlife Service in Nevada.
"Butterflies are important environmental monitors," he said. "They react to slight changes in their habitat, which can be a signal that something is wrong in that area."
One small population of skipper is found in California's Lassen County near Honey Lake, the other in Warm Springs Valley north of Reno, experts said.
The Fish and Wildlife Service, which is charged with enforcing the Endangered Species Act, took the emergency action last year out of concern that pending water export projects and other threats would doom the skipper butterfly to extinction.