Western Monarch Butterflies Near Record Low

Sign up for the Morning Brief email newsletter to get weekday updates from The Weather Channel and our meteorologists.

The number of monarch butterflies in California is in sharp decline this year, and biologists say record-high late summer temperatures and drought in the west likely contributed to the dropoff.

The Western Monarch Count has reported a peak population of just 9,119 butterflies this winter, down from approximately 200,000 overwintering butterflies counted each year over the past three years. This is the second-lowest population recording since tracking began in 1997.

Weather in your inbox

Forecast Location

Sign Up

By signing up you agree to the Terms & Privacy Policy. Unsubscribe at any time.

“The population’s size is extremely concerning,” Emma Pelton, an endangered species biologist with the Xerces Society for Invertebrate Conservation, said in a news release. “We know small populations are especially vulnerable to environmental fluctuations, and we think that’s what happened this year.”

Other threats to monarch butterflies include pesticides, habitat loss and climate change, according to Pelton. Also, January’s fires in Los Angeles County burned tree groves where monarchs overwinter, including a site in Lower Topanga Canyon.

Hundreds of volunteers and partners participated in the 28th annual Western Monarch Count by attempting to identify all of the overwintering monarch butterflies in California. The results coincide with monarch butterflies being proposed for protection under the U.S. Endangered Species Act.

Millions of butterflies were observed in the 1980s and scientists consider that a stable population level. The all-time lowest count was in 2020, when fewer than 2,000 western monarchs were observed.

“A lot of people care about monarchs. Voluntary efforts like pollinator gardens and restoring habitat are probably a reason they aren’t in worse shape,” Isis Howard, coordinator of the Western Monarch Count with the Xerces Society said in a news release. “However, these actions are not enough. To help monarchs recover, we need to work at a larger scale and address widespread issues like pesticide contamination and climate change that are beyond what voluntary efforts have been able to achieve.”

M​ORE ON WEATHER.COM

• M​agical, Mesmerizing Murmuration Of Starlings
• G​rammy Awards Raise $7 Million For LA Fire Relief
• W​atch Toboggans Slide Down Ice In Pennsylvania