The Western Monarch Count is a community science effort to collect data on western monarchs and their habitat during their overwintering season, when the butterflies are concentrated along the coast.

The Count is managed by the Xerces Society and count co-founder, Mia Monroe, who is also the co-founder of the Marin Monarch Working Group.

According to the results of the Western Monarch Count, the overwintering population in 2024 dropped to only 9,119 monarchs. This is only slightly above the all-time low recorded in 2020.

This year’s number is a sharp decline from that of the past three years. Each year from 2021 through 2023 over 200,000 monarchs were observed.

But as the graph below indicates, even these relatively high numbers are a far cry from the 1,200,000 butterflies recorded in 1997, the year the Western Monarch Count began.

In response to this crisis, there is a dire need to act at the local, state, and national level!

“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. 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.” Isis Howard, coordinator of the Western Monarch Count

“Like most butterflies, monarchs are highly sensitive to weather and climate. They depend on environmental cues (temperature in particular) to trigger reproduction, migration, and hibernation. Their dependence on milkweed alone as a host plant is a further vulnerability, particularly as milkweed abundance is declining throughout the monarch range. They also face a decline in their overwintering habitat, and the effects of an increasing frequency of extreme weather events such as drought and severe storms, and extremes in hot and cold temperatures.” World Wildlife Federation