Science & Tech · Science & Environment · 4 hrs ago
Monarch butterflies cross northern Mexico on their way to winter sanctuaries
Monarch butterflies began entering Mexico on October 5 as part of their autumn migration from the United States and Canada.
Early sightings were recorded in Coahuila, including Acuña, Múzquiz and Monclova.
By October 17, thousands had been reported in Sabinas, as winds from a cold front helped carry them south.
Specialists and members of the public are tracking the migration, while small transmitters help researchers follow some butterflies’ routes and resting places.
The butterflies are heading to wintering and mating sanctuaries in Michoacán and the State of Mexico, where they shelter in fir forests.
Their arrival usually begins in the first days of November, around Mexico’s Day of the Dead celebrations.
Monitoring will continue as the migration advances toward those sanctuaries.
The autumn migration of monarch butterflies into Mexico was confirmed on October 5, 2026, in Coahuila.
Thousands of butterflies were reported in Sabinas, Coahuila, in mid-October as they moved south.
Three butterflies fitted with tracking transmitters entered Mexico through Coahuila after travelling from the United States and Canada.
The butterflies are heading to wintering and mating sanctuaries in Michoacán and the State of Mexico.
- Who
- Monarch butterflies migrating from the United States and Canada.
- What
- They are crossing northern Mexico on their autumn migration to wintering and mating sanctuaries.
- When
- The migration was confirmed on October 5, 2026; thousands were reported in mid-October.
- Where
- Initial sightings were in Coahuila, with the destination in Michoacán and the State of Mexico.
- Why
- They are travelling to their wintering and mating grounds.
This story does not have two clearly opposing sides.
Profauna’s Correo Real program reported increased sightings in Coahuila, confirming the first monarchs had entered Mexico.
Reports said thousands of butterflies were in Sabinas, Coahuila; the article gives both dates for the reports.
Three butterflies carrying transmitters had crossed into Mexico through Coahuila, having travelled from the United States and Canada.
The butterflies are expected to reach sanctuaries in Michoacán and the State of Mexico, when they usually arrive.
- First confirmed entry
- October 5, 2026, in Coahuila
- Sabinas reports
- Thousands of butterflies; reported for October 16 and October 17
- Tracked butterflies
- 3 entered Mexico through Coahuila
- Distance travelled
- 2,252–2,645 kilometres from the United States and Canada
- Destination
- Sanctuaries in Michoacán and the State of Mexico