The thumb-sized mouse that refused to vanish has a new home

For decades, scientists believed the Pacific pocket mouse had vanished forever — a tiny rodent no bigger than a human thumb. Then a small group turned up in Orange County in 1993, and conservationists raced to save it. Now, twenty years into a breeding-and-release program, the San Diego Zoo Wildlife Alliance has given the species a third wild home: a new population on Marine Corps Base Camp Pendleton in Southern California. More than 500 mice have been released since 2006. Their burrows improve soil and water flow and shelter other creatures — proof that saving the smallest neighbors heals the whole neighborhood.