The Xerces blue butterfly vanished from San Francisco in the 1940s. Scientists just released dozens of butterflies from a related species to take its place.

The Fender’s blue butterfly is found only in Oregon’s Willamette Valley – a 150-mile long region in the state that stretches from Portland to Eugene – says the service. The species was ...

A 93-year-old Xerces blue specimen’s DNA shows that the butterfly is a distinct species, making it the first U.S. insect humans drove to extinction.

Dozens of silvery blue butterflies have been released at the Presidio National Park in San Francisco, Calif., to fill the ecological gap left by the Xerces blue butterfly, a native species last ...