"Think of a monarch butterfly, and a distinctive image pops up: black-and-orange wings, with a sprinkling of white spots around the black edges. Those white spots may actually help monarchs complete their long-distance migration by altering the air flow around their wings.

Or, at least, that's the provocative new claim from a team of researchers that has analyzed hundreds of monarch wings collected along its migration route.

"If you have larger white spots, you're simply more successful at reaching Mexico," says Andy Davis, a researcher at the University of Georgia.

He and his colleagues believe that the pattern of color could interact with sunlight to create subtle temperature differences on the wing that can alter airflow, easing the butterflies' flight."

Nell Greenfieldboyce reports for NPR June 21, 2023. [2]