First satellite-tracked Monarch butterfly
The annual migration of the Monarch butterfly is one of nature’s most breathtaking spectacles—a delicate yet determined journey spanning over 4,000 kilometers from Canada and the United States to the mountains of central Mexico. This year, the iconic voyage has reached a historic turning point. On November 12, the Secretaría de Turismo de Michoacán (Sectur) confirmed the arrival of the first Monarch butterfly equipped with a satellite transmitter to the Monarch Butterfly Biosphere Reserve, marking an unprecedented advancement in the scientific study of this species.
The butterfly, identified as MW026, is part of the Proyecto Colaboración Monarca, an international initiative using cutting-edge technology to monitor Monarch migration in real time. This breakthrough not only deepens our understanding of their routes and behavior but also reinforces global conservation efforts for a species facing increasing environmental challenges.
The journey of Monarch MW026: a route captured in real time
The story of MW026 begins on September 27, in Lawrence, Kansas (USA). Researchers from Monarch Watch released her into the wild fitted with a lightweight 60-milligram solar microtransmitter developed by Cellular Tracking Technologies (CTT). From that moment, the butterfly’s incredible trek unfolded step by step:
Crossing Oklahoma and Texas
MW026 fluttered south through Oklahoma and Texas, reaching Mexico sooner than expected. Her transmitter first signaled from Tamaulipas, near the El Cielo Biosphere Reserve, marking her official entry into Mexican territory.
Through San Luis Potosí and the Sierra Gorda
Her journey continued across lush valleys and rugged mountains, passing through Río Verde (San Luis Potosí) and into the Sierra Gorda of Guanajuato, areas known for their rich biodiversity and important ecological corridors.
Hundreds of kilometers closer
On November 7, MW026 was detected in Querétaro, specifically in Juriquilla and San José el Alto, demonstrating the remarkable endurance of these small yet resilient travelers.
Approaching the finish line
Just a day later, on November 8, signals placed her in Temascalcingo, State of Mexico, edging closer to her final destination.
Historic arrival in Michoacán
On November 9, MW026 reached Ocampo, Michoacán, landing in the celebrated El Rosario Sanctuary, located within the Monarch Butterfly Biosphere Reserve. This arrival marks the first successful record of a satellite-tracked Monarch completing its journey to Mexico.
A breakthrough for science and conservation
Roberto Monroy García, head of Sectur, emphasized the significance of this milestone. Never before had a Monarch butterfly fitted with a transmitter completed its migration into Mexico. This achievement signals a transformative moment in conservation science.
The project is led by David La Puma of Cellular Tracking Technologies (CTT) and supported by organizations across Canada, the United States, and Mexico. Its primary goal is to strengthen trinational conservation strategies, ensuring that the Monarch’s thousands-of-kilometers-long route remains protected for generations to come.
By tracking MW026’s path with unprecedented precision, scientists can identify critical habitats, migration bottlenecks, and environmental threats—knowledge essential to safeguarding the species amid climate change, habitat loss, and declining milkweed populations.
Monarch season in Michoacán 2025–2026: what to expect
Each year, millions of Monarch butterflies escape the cold of the north and seek refuge in the oyamel fir forests of Michoacán and the State of Mexico, where they hibernate until spring. The 2025–2026 migration season is already underway, and early signals like the arrival of MW026 suggest a promising and vibrant year.
Key dates for visitors and enthusiasts
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Mass arrival:
The majority of Monarchs typically reach Mexico between November 8 and November 20. -
Sanctuary opening:
The official opening of the Monarch sanctuaries for the public will take place on November 21, 2025. Visitors can explore sites such as El Rosario, Sierra Chincua, and Piedra Herrada, where the orange-and-black wings fill the sky in stunning displays. -
Peak season:
The most spectacular concentrations occur between December and January, when millions of butterflies cluster in the trees, creating a magical, almost surreal atmosphere. -
Season closure:
By mid-February, the butterflies begin to awaken. In early March, they embark on their journey back north, completing one of the most astonishing migration cycles in the natural world.
A symbol of hope for the future
The successful tracking of Monarch MW026 is more than a scientific achievement—it is a symbol of hope. It demonstrates what can be accomplished when technology, passion, and international collaboration come together in service of nature.
As we prepare for another breathtaking season in the forests of Michoacán, the story of MW026 invites us to appreciate the fragility and strength of these extraordinary butterflies. Their journey, now illuminated like never before, reminds us of our responsibility to protect their world—and, ultimately, our own.
