By Jeff Gaffney Every fall and winter, one of the most delicate, iconic, endangered visitors, the western Monarch butterfly, ...

The California Academy of Sciences used genetic testing to identify a blue butterfly species similar to the Xerces species that went extinct and disappeared from the San Francisco coastline ...

Pyle, an American, thought of the Xerces blue. “We should make that our symbol for butterfly conservation in the U.S.,” Pyle said.

SAN FRANCISCO — More than 80 years ago, a beautiful butterfly called Xerces blue that once fluttered among San Francisco’s coastal dunes went extinct as stately homes, museums and parks ate up ...

The new Silvery Blue butterflies in SF's Presidio will replace a long-lost species called the Xerces Blue that went extinct in the 1940s.

Xerces blue butterflies were believed to be a subspecies of the silvery blue, a species that was chosen because it was already well-adapted to San Francisco’s cool, foggy climate and relies on ...

People take a closeup view of silvery blue butterflies, the closest relative to the extinct Xerces blue butterfly, after their release in the Presidio’s restored dune habitat in San Francisco ...