Wave of butterflies lights up weather radar
It was a lacy, cloud-like pattern. It drifted across a radar screen. It was in the Denver area. It turned out to be a wave of butterflies. It was 70 miles wide. That's according to forecasters.
Paul Schlatter works for the National Weather Service. He said he first thought flocks of birds were making the pattern. But the cloud was headed northwest. It was going with the wind. Migrating birds would be southbound in October.
He asked birdwatchers on social media what it might be. He got his answer. People reported seeing painted lady butterflies. They looked like a loosely spaced net. They were drifting. They were going with the wind across the area.
Schlatter said the colors on the radar image are a result of the butterflies' shape. They are also a result of their direction. The colors he saw were not their own colors.
Midwestern radar stations pick up butterflies sometimes. Schlatter believes it's a first for Denver.
An unusually large number of painted ladies are sometimes mistaken for monarch butterflies. They have flown down on Colorado's Front Range. This has been in recent weeks. They feed on flowers. They sometimes fly together in what seem like clouds.
Sarah Garrett is a lepidopterist. She works at the Butterfly Pavilion. It is in Westminster. That is in Colorado. She said people from as far away as the Dakotas have called. They have reported seeing the butterflies. Their population typically surges with a lot of flowers.
Research on the painted ladies in North America is limited. Scientists think they migrate to the southwestern United States in the fall. They also migrate to northwestern Mexico.
Studies using radio tracking have shown they migrate south from Europe to Africa. This is in the fall. They return in the spring.
Studies also show that monarch butterflies often use wind to help. They glide on currents for periods of time, Garrett said.