Ventura, a postdoctoral biology investigator for the Massachusetts-based Woods Hole Oceanographic Institution said when announcing the findings that scientists reviewing the data “nearly fell off our chairs.”
“It was surprising,” Ventura told The Washington Post. “Because I was expecting the opposite.”
The findings, published last week in the journal Current Biology, illustrate behavior that had never been recorded in birds, Ventura said. While some birds like Atlantic yellow-nosed albatrosses and streaked shearwaters fly in the center of hurricanes for protection, he said no others have been found to fly behind the storms for up to five days and 1,512 miles at a time.
Desertas petrels, which live on Portugal’s Bugio Island, appear to chase hurricanes because the winds cause ocean mixing — the merging of warm water at an ocean’s surface with cooler water from below. That process makes the birds’ prey — squid, small fish and crustaceans — rise to the surface, making them easier to snatch.
To better understand the birds’ behavior, scientists tied GPS trackers to 33 Desertas petrels, hoping to learn more about their migratory movements and foraging areas. For a few weeks during the Atlantic’s hurricane season in 2015, 2016, 2017 and 2019, researchers tracked their locations while they searched the ocean for food — usually when they were most active at night.
In January 2020, Ventura and other researchers published a study that found that Desertas petrels fly for hundreds of miles at a time to search for food. But it wasn’t until last year that Ventura compared his data with hurricane maps.
He said he looked at the locations of six hurricanes between 2015 and 2019 — Gaston, Ophelia, Lee, Gabrielle, Maria and Lorenzo — through the National Oceanic and Atmospheric Administration’s climate tracker. Then, using his data, he examined where the birds went during the storms.
Multiple birds were found to be somewhere between 100 and 250 miles from all six storms. Surprised they were so close, Ventura said he took the data to Caroline Ummenhofer, an associate scientist at the Woods Hole Oceanographic Institution, late last year. She confirmed that the birds were following the trail of cool sea temperatures left by the hurricanes, Ventura said.
“It’s one of those moments that make the life of a researcher very exciting,” Ventura said. “It kind of clicks, and you’re like, ‘Oh, we have something here.’”
The birds withstood waves up to 26 feet tall and wind speeds of 62 mph to catch their prey, the researchers found. They typically circled the hurricanes in a clockwise direction — often for more than 24 hours at a time — before returning to their nests atop steep cliffs, only taking short breaks to sleep during the day.
“I like to think about them as very, very skillful sailors,” Ventura said.
Don Lyons, director of conservation science for the Audubon Seabird Institute, a bird conservation group, said he had never seen a seabird follow hurricanes, which can injure or kill birds that get caught in strong winds.
“It makes sense that some animals, including these petrels, have learned to take advantage of that [ocean] mixing,” Lyons told The Post. “What’s surprising, perhaps, is just how closely they follow the storm.”
Lyons said there are probably other animals that benefit from ocean mixing caused by hurricanes.
“This study will probably inspire people tracking other predators to look more carefully at the data they have or to design studies to look at these kinds of questions,” Lyons said. “… I’m very sure that [Desertas petrels] are not alone in taking advantage of this phenomenon.”
