Overwintering Monarchs

January 20, 2021 by Team Journey North

Ellen Sharp and Estela Romero provide updates from monarch sanctuaries in Mexico. Learn about how you can help monarch recovery efforts. And a reminder to monitor overwintering monarchs in the Southeastern U.S.

Clusters of Monarchs at Cerro Pelon Monarch Butterfly Sanctuary, Mexico. Photo by: Pato Moreno

Letter From Ellen Sharp: Climate Change

At Cerro Pelon Monarch Butterfly Sanctuary, Ellen Sharp explains that in recent seasons, climate change has expanded the window of monarch flight activity. This season, however, is not following that same trend. Dr. Sharp writes, "This season, weather patterns on the mountain more closely resemble the old normal than the new one: once again, it’s chilly and sometimes cloudy. Monarchs can’t fly when temperatures are lower than 13°C/55°F, and averages have been hovering around 11°C/51°F. From January 4th to the 14th, the colony stayed put on its trees . . . In other seasons in recent memory, the colony had already fluttered about so much that they’d relocated to a much lower clime by this date."

Read more of Ellen Sharp's Eighth Letter From Cerro Pelon Monarch Butterfly Sanctuary: Climate Change

Letter From Estela Romero: Observations from Sierra Chincua 

In her first letter since early December, Estela Romero provides reassurance that monarchs are present and doing well at Sierra Chincua Monarch Butterfly Sanctuary. She writes, "I am happy to report that monarchs can still be found in Sierra Chincua Sanctuary, contrary to what many observers in El Rosario had feared. Although the public can only view part of the colony at Sierra Chincua, what we did see was beautiful."

Read more of Estela Romero's Ninth Letter of the Season: Observations from Sierra Chincua

Monarch Numbers – And How You Can Help

As Ellen Sharp alludes to in her letter, The Xerces Society recently shared the final results from the 2020 Western Monarch Thanksgiving Count. The data paints a bleak picture: western monarch numbers are at the lowest point recorded since the count started in 1997. 

As we wait for data on the eastern migratory population of monarchs –expected in late February or early March – it is abundantly clear that all hands on deck are needed to save monarchs. What can you do? The Monarch Butterfly Fund and The Monarch Joint Venture provide a list of actions and resources to aid recovery efforts:

Monitor Overwintering Monarchs

Thank you to all who have participated in our targeted monarch butterfly monitoring project. Since December 1st, over 550 monarch observations have been submitted to Journey North. These observations will contribute to research efforts on overwintering behavior of monarch butterflies in the Southeastern U.S.

But your sustained help is needed. During January and February, please continue to report your monarch observations to Journey North.

Learn more about What to Report and view our Instructional Flyer.