Weather radar showed a strange blue mass in the eye of Hurricane Helene. What was it?

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Dark clouds from then-tropical storm Helene over Havana, Cuba, on September 25. | Yamil Lage/AFP via Getty Images
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Birds are incredible navigators, capable of traveling thousands of miles each year to the same location. But sometimes even they end up in the wrong place at the wrong time — like inside a hurricane. 

Last night, as Hurricane Helene was making landfall in Florida as a powerful Category 4 storm, radar spotted a mass in the eye of the storm that experts say is likely birds and perhaps also insects. 

Helene was a massive storm when it traveled across the Gulf of Mexico earlier this week. Seabirds likely fled the storm’s extreme winds — which reached 140 miles per hour — and ended up in the eye, where it’s calm. Once inside, they essentially got trapped, unable to pierce through the fierce gusts of the eye wall. When the storm dies down, the mass of birds will probably dissipate, Kyle Horton, a researcher at Colorado State University who studies bird migration, told Vox. 

Storms like Helene can blow seabirds like petrels, jaegers, and frigatebirds far inland. Exhausted, they end up in unfamiliar habitats where they can’t easily find food. “It’s a challenging situation,” said Andrew Farnsworth, a bird migration expert at the Cornell Lab of Ornithology. “We know that birds do die in these things.” 

Indeed, frigate birds — large seabirds with angular wings and a forked tail — were spotted by birders in central Georgia and even Tennessee this Friday as the storm churned inland. 

Though remarkable, it’s not uncommon for birds and insects to get trapped inside the eye of tropical cyclones, according to research by Matthew Van Den Broeke, a professor of earth and atmospheric sciences at the University of Nebraska Lincoln. Reports dating back to the 19th century — many of which come from ships — have documented this phenomenon, noting in some cases that the air was “filled with thousands of birds and insects.” One report documented an owl inside the storm.

In a 2021 study, Van Den Broeke analyzed radar from 33 Atlantic hurricanes that hit the US mainland or Puerto Rico between 2011 and 2020. Each one showed signs of birds and insects inside the eye of the storm.

Hurricanes like Helene can also substantially impact fall migration, when several billion birds migrate south ahead of winter. A map of migration from Thursday night, when Helene made landfall, shows that millions of birds were migrating west of the storm in places like Texas and Louisiana, but few if any were moving through Florida.

When skies clear after a storm, however, birds resume their migration en masse, Farnsworth said. “After the storm passes, we see these big explosions of birds at night,” he told me. 

It’s also worth remembering that birds have evolved with these storms for millennia. They can likely detect a coming hurricane by sensing things like changes in atmospheric pressure and they know how to hunker down when storms arrive, such as by orienting their aerodynamic bodies toward the wind.

“They’ve adapted to this, they’ve evolved with it,” Farnsworth said. “Yes, storms are getting more extreme. But birds know how to deal with these things.”