The final survey period of the Xerces Society’s Western Monarch Count ended recorded 6,464 monarch butterflies across 193 overwintering sites. This tally is 47% lower than the mid-season count of 12,260 butterflies, compared with 35%-58% seen in the past ten years.
Western Monarchs
With Upgraded Transmitters, We Can Now Track Migrating Monarchs Better than Ever
Xerces has been helping to test these new tags for over a year, and we are excited to finally put them into widespread use.
Western Monarchs Experience Average Winter Declines at Overwintering Sites
Migratory western monarchs experienced a 41% seasonal decrease at California overwintering sites compared to peak November tally.
How Urban Pesticides Can Harm Monarch Butterflies: A Cautionary Tale from California
In January 2024, volunteers stumbled upon a devastating scene: scores of dead and dying monarch butterflies near the Pacific Grove Monarch Sanctuary overwintering grove.
Mia Monroe of Mill Valley, California: A Monarch Whisperer With Data-Driven Devotion
Mia Monroe, both a founder and dedicated volunteer of the Western Monarch Count, can trace her conservationist spirit back to her childhood.