Secrets of the Monarch Butterfly
Scientists think they know why monarch butterflies have white spots on their wings.
© Marilyn Gould/Dreamstime.com
Why do monarch butterflies have white spots on their wings?
Monarch butterflies are beautiful! Their orange, black, and white wings look like they were painted by a talented artist. But scientists say the white spots on a monarch’s wings aren’t just pretty. They may help the monarch fly.
Each fall, some monarch butterflies migrate (travel) from Canada and the United States to Mexico. They spend the winter in the warmer climate. In the spring, they fly north again. The trip is about 2,000 miles (3,200 kilometers) each way. That’s a lot of distance to cover, especially for a tiny butterfly. Scientists wanted to know how monarch butterflies are able to fly all that way.
Scientists studied the monarch butterflies that were able to make it all the way to Mexico and those that were not. They found that the successful flyers had more white spots on their wings. Scientists also studied types of butterflies that do not migrate. These insects had smaller white spots than migrating monarchs.
The scientists think the white spots help monarchs because they cause sunlight to heat the wings differently in different places. This changes the airflow around the wings, making it easier to fly.
© Jose Carlos Macouzet Espinosa—Creatas Video+/Getty Images Plus
These monarch butterflies migrated to Mexico, where it’s warm.