It’s been roughly 80 years since the Xerces blue butterfly was last spotted flitting about on pastel wings across coastal California sand dunes. But scientists are still learning about the insect.

The Fender’s blue butterfly has fluttered away from the brink of extinction. The species, once so rare it was thought to be extinct, is no longer considered endangered, according to a January 11 ...

The endangered Palos Verdes blue butterfly, a thumbnail-sized creative that lives for less than a week, is making a comeback — with a lot of help from conservationists. The blue butterfly ...

State butterfly biologists Heidi Holman, left, and Heather Siart scout for frosted elfin butterflies in the Concord pine barrens, where the endangered Karner blue butterfly was reintroduced nearly ...

Corrections & Clarifications: The article has been updated to correctly reflect the Fender's blue butterfly's downlisting on the Endangered Species List. It remains on the list as "threatened." ...