Monarch Butterflies' Signature White Spots May Help Them Fly

These long-distance migrants could get a boost from their striking coloration, which may reduce drag by heating and cooling air unevenly

Carlyn Kranking
Assistant Editor, Science and Innovation

June 23, 2023



The white spots on the edges of a monarch butterfly's wings might give it an advantage while migrating, according to new research. Sanka Vidanagama / NurPhoto via Getty Images

For a migrating monarch butterfly, the key to success might be in its spots, according to a new study published Wednesday in the journal PLOS One.

Scientists suspected, based on past research about seabirds, that monarchs with dark wings would have the most successful flights. But their findings revealed the opposite.

Among 400 photographed pairs of monarch butterfly wings that the team examined, the ones with the most white spots belonged to the most successful migrants, which made it all the way to Mexico. The scientists say that having whiter wings could unevenly heat the wing surface in a way that reduces drag. This might allow the insects to move more efficiently on their impressive migratory journeys.

“No one even knew what these spots were for in monarchs,” co-author Andy Davis, an animal ecologist at the University of Georgia, tells the New York Times’ Kate Golembiewski. “All of a sudden, it seems like they’re really important.”

More:
https://www.smithsonianmag.com/smart-news/monarch-butterflies-signature-white-spots-may-help-them-fly-180982418/