Tropical storms and hurricanes are fearsomely destructive and can ravage oceanic and coastal ecosystems. Formed in tropical seas, a North Atlantic cyclone is classified as a hurricane if its winds exceed 74 miles per hour. Combined with normal tides, such storms can increase the sea level by more than thirty feet. Nearly every winter, dead seabirds—birds adapted for life in a marine ecosystem—are found washed ashore after such storms. Surprisingly, though, there is a group of seabirds, including albatrosses, petrels, and shearwaters, that seem attracted to these storms. Since ancient times, seafarers have considered the sighting of some of these species an omen, warning of an impending storm at sea.
In 2024, an international team of biologists reported their study of the Desertas petrel; a species of petrel that forages for food in the North Atlantic Ocean, flying a route of five thousand miles, on average, to do so. The researchers attached tracking devices to 33 of these birds to follow their movements. To their surprise, the researchers found that about a third of the birds interacted with cyclones and about half pursued their wakes, with a third of these persisting for several days and thousands of miles.
Why would they do that? The researchers think the storm’s mixing of warm surface water with the cooler water underneath causes the birds’ prey—squids, small fish, and crustaceans—to rise to the surface. This makes them easier to catch. The birds may detect the storms by hearing the low frequency sounds they make, at frequencies humans can’t hear.
Special thanks to Manon Clairbaux, Postdoctoral researcher, University of Cork, Cork, Ireland, for reviewing today's episode.
Further Reading
- Why a small seabird dares to fly towards cyclones Science News
- Most birds avoid hurricanes. This species chases them, scientists say Washington Post
- “We nearly fell off our chairs!” Scientists stunned to find rare ocean bird that actually chases tropical cyclones Discover Wildlife
- The astonishing foraging strategy of hurricane chasing birds, the desertas petrels The Animal Rescue Site
- Groundbreaking study reveals oceanic seabirds chase tropical cyclones, Woods Hole Oceanographic Institution
- Ventura et al. 2024, Oceanic seabirds chase tropical cyclones, Current Biology, 34, 3279-3285.