University of Georgia

Female flying aces

A monarch butterfly perched on top of a flower

Evidence has been mounting that female monarch butterflies are better at flying and more successful at migration than males, and UGA researchers have now come up with an explanation.

In a study comparing physical traits of female and male monarchs, they found that although female monarchs have smaller wings and smaller flight muscles than males, their wings are thicker and also bear less weight per square inch, making them both sturdier and more efficient in flight.

“Both of these elements would play important roles in determining the outcome of the migration,” said the study’s lead author Andy Davis, research scientist at UGA’s Odum School of Ecology. “Until now, we had no idea why females were better flyers than males, but this study definitely helps to answer that question.”

The female butterflies’ bodies tend to be lighter in relation to their wing size, making their flight more efficient.

“We believe this work will be important for improving scientific understanding of the migratory cycle,” Davis said, “and it will also serve as a reference point for future studies aimed at flight characteristics of monarch butterflies.”