Millions of monarch butterflies make a spectacular journey each year, traveling thousands of miles from the eastern parts of North America to reach their overwintering grounds in Mexico. Now, scientists have found out how these butterflies are so successful at traveling these vast distances. It turns out that it all has to do with the shape of their wings.
In this case, the scientists analyzed how the size, shape and color of wings differed among a collection of migrant butterflies. Although previous studies have looked at how much wing sized varied within a migratory season, they didn't account for specific measures of wing shape and color.