The great migration

By Anna Araoz

Monarch butterfly

We all, one time or another, admired a monarch butterfly as its fiery wings strike a perfect contrast with a flower it’s feeding on. But do you know what incredible natural phenomenon this delicate creature represents?

Monarchs perform one of the longest migration cycles on earth. It is considered the most important natural history discovery of all times. As Charles Darwin said: “evolution is written on the wings of butterflies“. Sophisticated navigators, they embark on a 3,000-mile journey that starts in Canada with its final destination on a remote mountain Cerro Pelón in Mexico. In this sanctuary, 500,000 million monarchs will hibernate over the winter months every year, forming spectacular living clusters to keep each other warm. And every winter season, a new generation of butterflies returns to the same section of the forest, to the same trees. Monarchs arrive in Mexico in November during the celebration of El Dia de Los Muertos. Local folklore has it that they are returning souls of children.

When winter is over, butterflies take off from their hideout in the rain forest and head back to Canada. It takes three to four generations of butterflies to complete the full migration cycle.

Sadly, deforestation, farming, urbanization, and climate change have been detrimental to the species. Monarchs rely on milkweed in Texas wildflower meadows, where they lay eggs halfway through their journey. This is the only plant their larvae will eat, but these milkweed nurseries disappear as more land is cultivated. Cities expand, taking over meadows and grasslands. Even the perfect microclimate of Cerro Pelón now experiences extreme temperatures, hurting wintering monarch colonies. Because monarchs face all these adversities, only one percent of all eggs and larvae survive.

But there is something we all can do to help monarchs survive. Next summer, when you choose flowers for your lawn, consider planting a butterfly garden. And when you see this mighty traveller land on a flower in your own garden, you’ll know you’ve made a difference, contributing to the success of the greatest migration on Earth.