Monarch butterfly
Monarch Butterfly Biosphere Reserve: The forest where the trees disappear beneath millions of butterflies.
Every winter, one of the most astonishing natural spectacles on the planet takes place. In the mountains of central Mexico, millions of monarch butterflies arrive after an incredible journey and completely cover the trees. From far away, it looks as if the trunks and branches have turned orange.
When the sun warms the forest, they all take flight at the same time. For a few seconds, the air fills with thousands upon thousands of wings moving all at once. It is such a spectacular image that it seems like something out of a movie.
A journey of thousands of kilometers
The Monarch Butterfly Biosphere Reserve is located between the Mexican states of Michoacán and the State of Mexico. There, large forests of oyamel firs grow, very tall trees that provide the perfect shelter for the butterflies during winter.
What is most surprising is that the butterflies are not born there. Every autumn they begin a journey of up to 4,000 kilometers from Canada and the United States. They are very small insects, but they travel an enormous distance to escape the cold.
When they arrive in Mexico, they find a mild climate that allows them to survive until spring. Then they begin the return journey north, where they will lay their eggs so a new generation can be born.
A forest covered in color
During the winter months, millions of butterflies gather close together on the trunks and branches. They cluster so tightly that, in some places, the bark of the trees can hardly be seen.
At first they look like dry leaves of brownish-orange color. But when the sun comes out and the temperature rises, they begin to move their wings and take flight. Suddenly, the whole forest seems to come to life.
Hearing the soft sound of millions of wings moving at the same time is an experience that is hard to forget. It is one of those spectacles that only nature can create.
A mystery that surprised scientists
For a long time, no one knew where the monarch butterflies disappeared to when winter arrived. Every year they left North America, and no one could follow their trail.
It was not until 1975 that researchers discovered the forests where they spent those months. The discovery surprised the world. For centuries, millions of butterflies had been gathering in the same mountains without almost anyone knowing it.
Today, scientists continue to study how they manage to find their way during such a long journey. The most curious thing is that the butterflies that arrive in Mexico have never made that trip before. Even so, they find the same place where their ancestors were.
A very special refuge
Oyamel forests are essential for the butterflies’ survival. Their branches protect them from the wind, the rain, and low temperatures during the winter. If these trees were to disappear, the butterflies would have much more difficulty completing their migration.
That is why the reserve is protected, and many people work to conserve this ecosystem. It is also important not to disturb the butterflies when they are resting, since they need to conserve energy to continue their journey in spring.
A Unique Natural Treasure
The Monarch Butterfly Biosphere Reserve was declared a World Heritage Site because it is home to one of the most impressive migratory phenomena on the planet. Very few places allow you to see millions of animals gathered in such a small area.
This forest shows that even an insect as light as a butterfly can carry out one of nature’s greatest migrations. Seeing the trees completely covered in orange wings is an image that seems impossible, but it happens every year in Mexico. That is why this place is one of the world’s great natural treasures and a spectacle that never ceases to amaze.
