California urges public to log monarch sightings as numbers near historic lows

Ahead of California’s Biodiversity Day, the California State Parks Foundation is urging the public to log monarch butterfly observations to aid scientific monitoring. Citizens can use the iNaturalist app to submit photographs, providing data for the 30th Western Monarch Count. The most recent survey, covering late November to early December 2025, logged roughly 12,260 monarchs, marking the third-lowest tally since the count started in 1997 and a sharp drop from the low-million figures typical in the 1980s. Officials attribute the decline to habitat loss, climate change and pesticide exposure.

The monarch was classified as endangered globally by the IUCN in 2022, though it remains only proposed as threatened in the United States. The citizen-science effort aims to fill knowledge gaps and inform conservation strategies as the species faces mounting pressures.