Beginning in late August every year, large masses of Monarch butterflies leave Canada and the northern United States (in the area of the Great Lakes) to travel about 3,000 miles to winter in the Oyamel forests of Central Mexico. The trip can take three to four months, traveling as fast as 12 miles per hour and 50 miles per day. Along the way, new butterflies are born, replacing those that die during the trip. Arriving at their destination, the butterflies cluster in large numbers on the branches and trunks of the Oyamel trees, staying fairly still and conserving their energy. While wintering in Mexico, between 40 and 60 percent will die.
The return trip begins in late February and early March. More butterflies will be born along the way to aid in the spring flight back to Canada. In fact, the entire process of Monarch migration takes up to four generations of butterflies. Monarchs are the only butterflies to make such a long, two-way migration every year. Unlike birds and whales, the Monarchs that left Canada typically do not make the entire round-trip. It is thought that the first generation may reach as far north as Texas and Oklahoma during the spring migration. It is the second, third, and fourth generations of offspring that return to the north in the spring.
Entomologists (IN-tuh-MOLL-uh-justs)—scientists who study insects—remain baffled by many aspects of the Monarch butterfly. Though many guesses have been put forward, no one knows for sure why Monarch butterflies even migrate, why they fly so far, how they find their wintering sites each year, or why they travel to the same winter roosts—often to the exact same trees. No one knows exactly how their homing system works.
Even as God caused Job to realize that we humans do not understand many of the mysteries and wonders of God’s Creation (Job 38-41), so scientists continue to try to unravel the unsolved mysteries of Monarch butterfly migration. Migration is yet another proof of the divine Designer Who created all things and wove His wisdom into the intricacies of His Creation.