Once, millions of monarchs wintered in California. But climate change, habitat loss, widespread pesticide use and disease ...

This winter, volunteers from the Xerces Society, a nonprofit environmental group, tallied just 9,119 western monarchs — a ...

Newly released data shows that the number of monarch butterflies migrating to California this winter is near-record low. "We ...

In 2023, more than 16,000 butterflies were counted at one local grove. The most recent count was a tiny fraction of that.

The number of monarch butterflies spending winter in the western U.S. dropped dramatically this year, despite moves to extend ...

While the butterfly’s population has been declining ... “No matter where you come from in California, monarchs are around. … The thought of them being gone is heartbreaking.” ...