While it’s now possible for you or I to hop on a plane and fly from the U.S. to destinations in all (or nearly all) continents, humans were far from the first to figure out flying long distances: our feathered friends have been participating in marathon bird migrations for millennia.
Now, thanks to a new study that analyzed global tracking data from 48 species of pelagic–or ocean-going–seabirds, we now know that these thousand-mile migrations are often made using six distinct “flyways.” Flyways, like highways in the sky, follow ocean-driven wind currents, allowing seabirds to use less energy flapping their wings as they soar along, carried by the wind.
Here’s a helpful map put together by the researchers:
🚨NEW OA PAPER🚨@GEB_macro details how we delineated six #MarineFlyways using #seabird #tracking data & novel analytical methods
➡️ https://t.co/R1djOpiteH #ornithology #migration #BLScience
We’re grateful to @GOBIsecretariat @iki_germany for funding the project
🧵1/5 pic.twitter.com/nodkrV8jks
— BirdLife Marine (@BirdLifeMarine) February 17, 2025
We’ve know about flyways over land for years: mapping overland bird migration routes has allowed countries to work together to better protect birds as they make their long journey from their summer to winter homes and back. But for the more than half of seabirds that spend their lives primarily out in the open ocean (technical name: pelagic), their migration routes don’t follow their terrestrial peers.
This new research highlights the impressive stamina of seabirds the world over, many of which migrate every year between feeding grounds and nesting sites in opposite hemispheres. From the figure eight-flyways over the Atlantic and Pacific oceans to the circumnavigation some seabirds undertake in the Southern ocean, these are epic journeys that, prior to the invention of air travel, humans could only dream of.
Even in the remote islands of Papahānaumokuākea Marine National Monument, seabirds still contends with plastic pollutionPhoto by Ryan Tabata/NOAA | Public Domain
But as we learn about seabirds’ annual migration pathways, we are also faced with the sobering reality that these journeys are growing rarer: seabirds are one of the most threatened groups of vertebrates globally, with 56% of seabirds species facing declines in their populations. While hunting drove seabird declines in past centuries, today’s top threats to seabirds include invasive species and development, which threaten their nesting grounds, and getting caught in fishing gear as they feed (also known as bycatch). Seabirds are also threatened by broader global problems such as climate change and plastic pollution.
To see seabirds soaring in the skies for years to come, we need to do more to protect our ocean, to ensure their nesting sites and feeding grounds the globe over are places of abundance that make the birds’ epic journeys worth the thousands of miles they travel on these highways in the sky.
