Decades after the Xerces blue butterfly went extinct in San Francisco, scientists are bringing them back … or their cousins anyway.

Scientists in San Francisco have released dozens of butterflies from a related species to take its place, hoping to restore the hole left in the ecosystem when the Xerces butterfly left.

For more on this, KCBS Radio anchors Patti Reising and Bret Burkhart were joined by Durrell Kapan, Senior research fellow at California Academy of Sciences who worked on the project.