Space weather is exactly what it sounds like: variations in the environment between Earth and the Sun, influenced by factors like solar wind and the ionosphere, the buzzing layer of the atmosphere that is ionized by solar radiation. Birds rely on the Earth’s magnetic field to navigate, yet until recently it was unclear whether space weather could make it more difficult for these same birds to fly. Now a recent study in the journal Proceedings of the National Academy of Sciences suggests the answer is yes.
“Our results suggest that fewer birds migrate during strong geomagnetic disturbances and that migrating birds may experience more difficulty navigating, especially under overcast conditions in autumn,” the authors explain. To learn this, the authors analyzed an unprecedented quantity of data about how birds migrate, drawing from visual information gleaned by 37 NEXRAD Doppler weather radar stations over a period of 23 years. They then cross referenced that data with information about geomagnetic disturbances within those same regions. By doing this, the scientists learned whether events like severe space weather events that disrupt the magnetic field — most notably solar flares — had a measurable effect on those birds who migrated across a 1,000 mile swatch of the Great Plains from North Dakota to Texas.
They learned that the number of migrating birds in the Great Plains region decreases on average from 9 percent to 17 percent during periods of severe space weather. Additionally, there were more examples of birds getting lost while migrating, a phenomenon known as migratory bird vagrancy. Birds were also less likely to fly against the wind “under both overcast conditions and high geomagnetic disturbance,” due to “a combination of obscured celestial cues and magnetic disturbance.”