Solar flares disrupt bird migration. University of Michigan study reveals hidden impact of geomagnetic disturbances

While it is well established that the Earth's magnetic field plays a crucial role in the navigation of birds and other animals, the effects of disruptions in this field, instigated by solar activities, on animal behavior are less known. These disturbances can influence not only the animals but also the functioning of satellites and other devices.

In an endeavor to explore this issue, researchers from the University of Michigan undertook a thorough study to determine how disruptions in Earth's magnetic field impact bird migration at night. For the study, they scrutinized data from radar stations on the ground, functioning in the Great Plains of the USA, a primary bird migration route.

The radar information revealed the flight paths of bird groups that ranged from hundreds to thousands in number, primarily consisting of species such as sparrows, thrushes, ducks, swans, and geese. Furthermore, the researchers utilized information from a global network of ground-based magnetic field detectors.

According to the study, during turbulent space weather provoked by intense solar activity, birds flew 9-17 percent less. Those that did attempt the journey often encountered navigation difficulties, particularly during autumn when the sky was predominantly clouded.

"Our findings highlight how animal decisions substantially depend on environmental conditions, including less noticeable elements such as disruptions in the geomagnetic field. Behavioral changes can influence the movement of entire populations." - Eric Gulson-Castillo, the primary author of the study.

Professor Ben Winger, another author of the project, stressed, "Our data explicitly points out that migration intensity diminishes during severe geomagnetic disturbances. It gives an ecological backdrop for decades of research on animal magnetoperception mechanisms by underlining the ramifications of space weather on migration dynamics."

A review of the data also implied that birds are more inclined to flow with the wind during geomagnetic disturbances. Amid dramatic magnetic turbulence and overcast skies, the intensity of comfort flights (against the wind) reduced by 25 percent. These factors suggest navigation complications instigated by magnetic field disruptions and reduced visual cues in the sky.

"We deduce from our findings that fewer birds migrate during dramatic geomagnetic disturbances. Birds in transit may encounter navigation challenges, especially in autumn and under cloudy circumstances," Gulson-Castillo, who carried out the study for his doctorate thesis, noted. "As a consequence, birds may exert less effort into active navigation during flight, thereby aligning more with the wind's direction."