Monarch Butterfly Migration
Every autumn, monarch butterflies depart from North America on one of the longest natural migration paths. They migrate almost 3,000 miles, beginning in southern Canada and parts of the United States, to the mountains of central Mexico to spend the winter before returning in March. No one monarch butterfly makes the entire voyage, and it may take up to four generations to finish it.
While some butterfly species do migrate, such as the monarch butterfly on other continents, their migration paths are typically much more restricted. The evolutionary origins of monarch butterflies, the only butterfly species that makes such a difficult, generation-spanning trek solely to spend the winter, are still somewhat a mystery. But according to a study from 2016 headed by a mathematician at the University of Washington, we now know how they accomplish it.
He rebuilt the internal compass that butterflies use to navigate by mapping the brain activity of butterflies with the help of other experts, such as neurobiologists. He discovered that butterflies go southward and northward throughout the day without the aid of outside cues by using the position of the sun in conjunction with their internal clocks.
