Wildlife

Monarch Butterfly Winter Roost Conservation

Monarch butterfly overwintering sites are critical concentrated populations vulnerable to habitat loss, illegal logging, and extreme weather events.

Key Facts

Eastern monarchs overwinter in oyamel fir forests in central Mexico
Western monarchs overwinter in eucalyptus groves along the California coast
Climate events like ice storms have killed millions of monarchs at roosting sites
Overwintering populations have declined by over 80 percent since the 1990s
The Mexican government and indigenous communities protect core butterfly sanctuaries

Welfare Considerations

Monarchs at overwintering sites are clustered in their highest densities, making them maximally vulnerable to catastrophic welfare events. Illegal logging removes the microclimate buffering of the forests, exposing butterflies to lethal temperature extremes. Protecting overwintering habitat is the single most impactful conservation action for this species.

What You Can Do

Support World Wildlife Fund Mexico and Monarch Butterfly Fund
Advocate for stronger protection of Mexican overwintering forest
Plant native milkweed on the breeding grounds to support summer populations
Participate in citizen science monitoring of monarch populations
Learn about the biology of monarch migration and share this information