Tag Archives: oyamel fir trees

Monarchs Arrive for Day of the Dead

It’s early November and, monarchs have finally completed their migration! The ones who have beat all the odds and survived predators, parasites, storms and a 3,000 mile flight, are ready to rest for the winter months in the Transvolcanic Mountains of Mexico.


Map of monarch migration.

During winter, the normally solitary monarchs will roost in large groups to stay warm and maintain fat reserves they’ve accumulated from the fall, clinging tightly to each other in oyamel fir forests. These tiny, dwindling stands of trees provide a microclimate with ideal temperature, humidity, and elevation for monarchs to overwinter. On brief, sunny occasions, monarchs will venture off in search of water, never straying too far from the protective cover of the mature fir canopy.

Monarch populations are monitored during the winter months because their distribution is so widespread during the migration and breeding seasons. While breeding populations in late summer are much larger, many monarchs don’t survive the migration and therefore do not contribute to the next spring’s generation. NatureServe and The Xerces Society for Invertebrate Conservation estimate monarchs occupy about 1.65 acres of oyamel fir forests across 12 different locations, a sharp decline from the 50 acre stand used by wintering monarchs in the late 1990s. As many know, the populations have dropped significantly in the last 20 years. Last winter marked the smallest overwintering monarch population that has ever been recorded. There are many factor influencing the decline of monarch populations. The occurrence of episodic weather events and loss of summer breeding habitat contribute to declining numbers, while illegal logging and invasive species have fragmented and compromised the integrity of the oyamel forests in which the monarchs overwinter.

Monarchs feeding on nectar.

Monarchs feeding on nectar.

If this fascinating journey and tale of survival wasn’t interesting enough, the arrival of the monarchs coincides with a significant event in Mexican culture. October 31 marks the beginning of  “El Dia de los Muertos” or Day of the Dead, a time when everyone comes together to celebrate and remember deceased family, friends, and ancestors. Monarchs arriving at the wintering grounds in Mexico this time of year are the “great grandchildren” of the monarchs that began the migration cycle in March of the previous year. Unlike their parents and grandparents that lived for several weeks, the migrating generation will live upwards of nine months as they overwinter in Mexico.

Day of the Dead artwork by Ryan Connors.

“The Monarch Returns.” by Ryan Conners

Day of the Dead coincides with the Christian holy days, All Hallows Eve, All Saint’s Day, and All Souls days which are celebrated October 31 through November 2. As Catholic traditions and indigenous cultures mixed, monarchs have come to represent the souls of loved ones returning to visit each year.

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Small but Mighty

It’s that season again! You may be noticing small flashes of orange whiz past as you drive, or wings fluttering outside your living room window.  The monarch butterfly migration is in its earliest stages! All summer long, monarchs have been munching away on their favorite milkweed snack, and growing as fast as ever. Check out the clip below:

It only takes about a month for the Monarch to go through its entire metamorphosis and bring the next generation into the world. These beautiful insects live 2-5 weeks while enjoying the summer season and continuing their genetic line. Incredibly, this cycle can occur about three times throughout the summer! On the fourth generation, however, something spectacular takes place. The Monarch eggs laid in late August and September are destined for something much more magnificent than their three previous generations.


A chrysalis only moments before it emerged. The orange and black pigmentation is the last stage of development during the pupal stage.

Our fourth generation monarchs are the migrators. We will be seeing these guys as caterpillars and butterflies in the upcoming weeks. These monarchs will develop into physically and behaviorally different insects than their parents and grandparents. Born with an underdeveloped reproductive systems, these little guys were created to channel all of their energy into one thing: flight. Weighing only one half of a gram, these mighty flyers fuel up on nectar for their migration to Mexico for the winter. The 2,000-3,000 mile journey is extremely dangerous and monarchs are at risk from large storm events and lack of feeding and breeding habitat.  Only a small percentage of monarchs will make it to their destination. The lucky survivors arrive in just in time for the Mexican Holiday, Day of the Dead, where it’s believe monarchs are the souls of loved ones that return each year. 


You can identify this monarch as a female by the lack of black patches on the hind wing.

After taking shelter in the Oyamel Fir forests in the Transvolcanic Mountains of central Mexico, the monarchs begin their journey north in March, now fully mature. During their journey, they will reproduce and eventually die, having lived up to nine times longer than the first three generations. In addition to being an iconic species, the monarchs play a vital role in our ecosystems, supporting plant and wildlife biodiversity. Unfortunately, monarch populations have declined by 90 percent in the last 20 years. We can help by planting milkweed, reducing our pesticide use and spreading the word about these small but mighty butterflies! Over the next several weeks, I’ll be sharing stories about what we’re doing to help with our partners and how you can also help this iconic species.

In the meantime, to learn more about the plight of the monarch and what you can do to help, visit our Save the Monarch page!