The beautiful Monarch butterfly is a wonder of nature. They migrate every year from locations as far north as Canada. With four separate generations, they over-winter in Southern California and Mexico. The Monarch accomplishes this feat by methods that are still being studied today. The are thought to use their polarized light sense to measure day length. They have magnetite in their wings that helps guide them toward trans-volcanic mountain ranges. They have adaptations to use solar power and ride wind drifts, and they cluster together in groups of hundreds of thousands to ensure survival. Along the way they feed upon Millkweed and Golden Rod. They roost at night in historically safe havens and they endure flight across thousands of miles of every kind of terrain from mountain to desert, and even open water.
The butterflies make a sort of funnel-shaped congregation every year as they come from both sides of the continent. They leave in about October or November of each year. Days are getting shorter, and the butterfly will instinctively know when to take off. In north and central Texas they meet for a central flyway route toward the border.
The Oyamel fir forests in Mexico are the final destination to the last generation of butterflies to make the trip south. Once there, they can breed, eat and begin the cycle anew. How they are able to know precisely where, when and how to travel without ever having made individual journeys is a mystery still. But the many clues of their light sense, their magnetic guidance, their unique coloring and more – all play a part. On the return trip, the final generation of each cycle, called the Methuselah butterfly, lives longer than the original three to four months of its parents and grandparents. This final generation is somehow programmed by nature and environment to live up to nine full months to complete the return journey home to the north.
The North American Monarch migration of this Danaindae butterfly is celebrated by many of the people along the route. The display of hundreds of millions of butterflies taking to the skies is rare and a cause for amazement.
Recent wildfires have destroyed much Milkweed and caused hardship for the butterflies, so conservation efforts are continually emerging to protect the travelers from this and other activities that can be influenced by human beings, such as deforestation. Almost everyone who learns about this one-gram size-and-weight wonder is transfixed at their trip and in awe of their accomplishment.
Another remarkable aspect of the migration is that the butterflies will return to the same tree from which their parent or grandparent butterfly began in Mexico. In all, the four cycles of butterfly generations make a trip that even most migrating birds find intense or impossible.
The Monarch is fascinating but also beautiful and inspiring. A butterfly is not typically regarded as the strongest and toughest creature on Earth, but the more these remarkable insects are studied, the more they are recognized to be both resilient and extremely tenacious. The migrating Monarch is determined and very tough indeed.