A monarch’s life is a story of enormous transformation. They start as an egg, and within a few days they emerge as a ravenous caterpillar. After 10-14 days of munching on milkweed leaves, the monarch forms a chrysalis. Over the next two weeks it undergoes a radical reorganization of its tissues, ultimately tearing free from its confinement as an adult monarch butterfly. If it hatched in the summer, it may live for another 2-5 weeks. In early fall, the final generation of monarchs has a special job: to migrate. This special generation may live up to 8 months.
Learn more about monarch butterflies and how you can help them along on their journey.
A Scientist's New Method
Tagging a fluttering insect that weighs only a few grams can be pretty difficult. That was one of the challenges that Fred and Norah Urquhart had to overcome in their journey to track monarchs.
After spending years trying to figure out a way to successfully tag monarch butterflies – a tedious process because their wings are very delicate and moisture-sensitive – Fred and Norah finally had a breakthrough in 1940. Thanks to a recent innovation that created the sticky material we now use on post-it notes, they created a tag with a similar material that managed to stick. Once they began tagging huge scores of monarchs the two soon realized they were going to need some help.
Fred and Norah founded the very first Insect Migration Association, known today as Monarch Watch, enlisting multitudes of volunteer “citizen scientists” all across North America to tag hundreds of thousands of butterflies and track their migration routes. In 1975, this ultimately helped Dr. Urquhart find out that these monarchs migrated from Canada all the way to the forests of Central Mexico.
A Truly Marvelous Migration
It takes two to three generations of monarch butterflies to migrate north from Mexico through the U.S. up to Canada. Over time, the monarchs have developed a ‘Super Generation’ to make the longest leg of the journey southward. This ‘Super Generation’ is bigger, lives eight to 10 times longer, and unlike other generations does not mate during the journey.
Monarchs stay in Mexico over the winter to rest and after several months make the first part of their journey back to the U.S. and Canada. By the time they get to Texas, they lay eggs and die, thus starting this amazing cycle again. Scientists have not been able to fully explain what triggers this mystery of the natural world.