Just as smartphones have made physical phone books obsolete, navigation apps are making it harder for us to remember directions. It's not just a human issue, but birds are also facing their own navigation problems.
A recent study has dived into the history of bird migration and the impact of space weather events on it. These events disrupt the migration of many birds, including perching birds like thrushes and warblers, as well as ducks, geese, swans, sandpipers, and plovers.
Humans can't feel Earth's magnetic fields, but birds, sea turtles, trout, and others have developed organs to sense them. Birds often rely on these internal compasses for long-distance migration, but when space weather like solar outbursts messes with Earth's magnetic fields, it leaves them lost.
Data from Doppler radar stations and magnetometers shows that during these space weather events, 9-17% fewer birds migrate in the spring and autumn. Birds flying at night have a tough time navigating with their unreliable compasses, especially in overcast autumn conditions.
High geomagnetic disturbances not only reduce the number of migrating birds but also cause them to drift aimlessly with the wind. During strong solar storms in the fall, birds flying thousands of kilometres across the US Great Plains put in only three-quarters of the effort to battle crosswinds and often get lost.
