Plan a visit to the Butterfly Pavilion, a zoo just outside Denver, Colorado, and be prepared to see the place teeming with children, agog at being up close and personal with invertebrates from tarantulas and worms to scorpions. There are, of course, butterflies, hundreds of them in many colors and sizes, fluttering about inside a massive greenhouse resembling a rainforest called “Wings of the Tropics.”
Sublime childhood memories of nature, whether at a zoo or in the wild, can last a lifetime—and be reawakened—as they were for Ricardo Ballesteros, Consul for Economic, Cultural, and Cooperation Affairs, at the Consulate General of Mexico in Denver, when he visited the Butterfly Pavilion in 2023.
“I remember, I think that I was like six years. It was one of my most impressive images in the sense that you see thousands, probably millions of butterflies just all over a forest.” Ricardo’s visit to the Butterfly Pavilion rekindled images of his trip long ago to the Monarch Butterfly Biosphere Reserve—a UNESCO World Heritage Site about 2.5 hours west of Mexico City in the states of Michoacán and México—where monarchs (Danaus plexippus) gather every winter after migrating from the U.S and Canada. It also informed him about their falling numbers and that action was needed to protect them.
Sharing his awe of being in the Reserve in Mexico is Shiran Hershcovich, the lepidopterist manager at Butterfly Pavilion, “I don't think I still have any words that could do any justice to this phenomenon. It's just so majestic, being surrounded by millions of butterflies and the only sound you hear is the sound of butterfly wings. Anybody who's ever stood in this place will understand the importance of protecting this magical place.”
Unfortunately, Hershcovich says the migratory monarch butterfly has shown steep declines over the last couple of decades—the western monarch of over 90 percent and the eastern monarch of over 80 percent. Pesticides and habitat loss are the main reasons, but climate change is also a factor, by potentially shifting when monarchs migrate and the availability of native plants as they make their 3,000-mile trek to and from Canada.
If monarchs do make it to Mexico on their southward migration, they’ll find that the Reserve has been reduced because of development and logging.
So, when the idea was floated to form a partnership between the Butterfly Pavilion and the government of Mexico to safeguard the monarch migration, Ballesteros didn’t hesitate. Together they’re working to restore this essential habitat in Mexico of which only an estimated ten percent remains. This summer, the partnership will be planting 100,000 oyamel fir trees (Abies religiosa) in the Monarch Butterfly Biosphere Reserve.
Scientists aren’t sure why an estimated one billion monarchs congregate on the limbs and bark of oyamel fir tree in the Reserve, but perhaps they’re drawn to its strong scent, or maybe because the area is volcanic with distinct minerals and compounds that may help guide them. Hershcovich says researchers believe that monarchs use the magnetic fields created by the area to navigate, using a carefully calibrated system of navigation that we are still trying to fully comprehend.
In addition to planting the trees in Mexico, an educational outreach program will be established by partnering with schools to create pollinator gardens in the buffer zone of the Reserve as “living classrooms,” where students can learn about monarchs, pollinators, and conservation practices that protect biodiversity. The plants will provide nectar that monarchs and other insects rely on. Hershcovich says monarchs are closely tied to their surroundings, so when a habitat is degraded, butterflies are one of those first animals to show signs of damage. One example is the well-known relationship monarchs have with milkweed. “Should there be no milkweed, the monarch butterfly does not lay eggs, and then populations may crash rapidly.” Monarchs, in turn, support ecosystems across North America as they migrate, carrying pollen to flowers, boosting plant reproduction, and benefiting the wildlife that depends on those plants for food.
Monarchs aren’t the only butterfly species in decline. A study Hershcovich co-authored in March found that, in the last 20 years, we've lost just over 20 percent of the butterflies in North America. That’s devastating both from an ecological and social perspective, especially in Mexico where the monarchs have been a part of the culture for centuries. Their migration corresponds with Día de los Muertos, or Day of the Dead, and tradition has it that the arriving monarchs are the souls of loved ones returning for a visit into our earthly realm.
There might be something to the notion that butterflies want to communicate. As we talked in the greenhouse, a large female black-and-tan butterfly laid several eggs on my producer’s sleeve and repeatedly landed on our microphone. Perhaps it wanted to tell us that over 200 species coexist in this space, sharing its resources without conflict. Or maybe it wanted to say that despite news about tariffs and immigration, it thinks this new partnership between a U.S. organization and Mexico shows that butterfly diplomacy can transcend borders to protect nature. 💧