Monarch Migration Begins

Monarch butterflies begin their annual migration across North America amid severe population declines.

Monarch butterflies are beginning their annual fall migration, prompted by cooling temperatures, shorter daylight and changing winds. The eastern population may travel up to 3,000 miles to central Mexico, while western monarchs generally head to sheltered groves along California’s coast; a long-lived “super generation” makes the journey and overwinters before returning north to reproduce in spring. Migration typically unfolds from August through November, with timing varying by region and weather, and the butterflies often gather in nighttime roosts containing hundreds or thousands of individuals. Natural Bridges State Beach near Santa Cruz is California’s only state monarch preserve and usually hosts butterflies from mid-October through mid-February. Monarch populations have declined sharply, particularly in the West, prompting conservation efforts and public programs focused on threats, environmental conditions and ways communities can support the species.

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