Monarch butterflies with more white spots on their mostly orange-and-black wings are more successful at long-distance migration. Some scientists think the spots may affect airflow around their wings.

Monarch butterflies with more white spots on their mostly orange-and-black wings are more successful at long-distance migration. Some scientists think the spots may affect airflow around their wings.

Monarch butterflies have distinctive orange-and-black wings with small white spots. And it's those spots that recently caught the attention of a group of scientists. As NPR's Nell Greenfieldboyce ...

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.

Monarch butterflies with more white spots on their mostly orange-and-black wings are more successful at long-distance migration. Some scientists think the spots may affect airflow around their wings.

Monarch butterflies with more white spots on their mostly orange-and-black wings are more successful at long-distance migration. Some scientists think the spots may affect airflow around their wings.