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

Scientists are grappling with a stark population decline of the western monarch butterfly after the species’ numbers hit a ...

Monarch butterflies are important culturally and ecologically across North America. Generations have watched in wonder as yellow-and-black striped caterpillars fold into green-and-gold chrysalises and ...

The Western population of the monarch butterfly has reached the second-lowest level recorded since tracking began nearly ...