Butterfly Populations in the U.S. Decline by 22% Over Two Decades

A comprehensive study highlights alarming trends in butterfly losses and calls for urgent conservation efforts.

Between 2000 and 2020, butterfly abundance across the continental U.S. dropped by 22%, with 107 species losing more than half their populations.
Habitat loss, insecticide use, and climate change are identified as key drivers of the decline, with the Southwest experiencing the steepest losses due to rising temperatures and drought.
The Pacific Northwest showed an apparent population increase, primarily due to a boom in the California tortoiseshell butterfly, which is not expected to last.
Butterflies play critical roles as pollinators and indicators of ecosystem health, yet 13 times as many species are declining as increasing, raising biodiversity concerns.
Conservation strategies, including habitat restoration, reduced insecticide use, and native wildflower planting, offer hope for reversing these trends.