Solar storms and disturbances, which can trigger beautiful auroras, might have a less picturesque consequence: they appear to trouble migrating birds. A team from the University of Michigan has unveiled a correlation between space weather and challenges faced by birds during their nocturnal migration.
Birds, like various other creatures, rely heavily on Earth’s magnetic field for navigation during their seasonal migrations. But what happens when solar outbursts disturb this magnetic field?
To uncover the answer, researchers turned to vast datasets from U.S. Doppler weather radar stations and ground-based magnetometers, which gauge local magnetic field intensities. They observed a 9% to 17% decline in bird migrations during severe space weather events. Additionally, those birds that ventured to migrate in such conditions found navigation especially challenging under overcast autumn skies.
“This discovery emphasizes how sensitive animal behaviors are to environmental conditions, including some that are imperceptible to us, like geomagnetic disturbances,” says study lead, Eric Gulson-Castillo, a doctoral student at the U-M Department of Ecology and Evolutionary Biology.
While disturbances in Earth’s magnetic field can mess with satellite communications, human navigation, and power grids, little is known about how these fluctuations affect migrating birds. This new study offers a broad perspective, utilizing 23 years of bird migration data across the U.S. Great Plains.
During their investigation, researchers detected groups of hundreds to thousands of migrating birds, primarily comprised of perching birds like thrushes, and warblers, shorebirds like sandpipers, and plovers, and waterfowl such as ducks and swans. The birds seemed to drift with the wind more often during geomagnetic disturbances in autumn, instead of fighting against it. This “effort flying” against the wind diminished by 25% under cloudy conditions during significant solar disturbances.
Ben Winger, the study’s senior author, notes, “Our findings demonstrate the vast impacts of space weather on migration dynamics, providing an ecological context to decades of research on animal magnetoreception mechanisms.”
This groundbreaking study offers new insights into the complex interplay between the Earth’s magnetic field and the animal kingdom, revealing that the cosmic disturbances of space weather might have more earthly consequences than previously thought.
