Much like advanced mobile phones have rendered our pocket diaries obsolete, navigation apps are gradually diminishing our ability to recall routes independently. It's concerning that humans face this issue, but it turns out that birds are also grappling with their own set of navigation problems!
A study examining historical
bird migration patterns and
Earth's geomagnetic events has revealed that space weather events are causing significant disruptions in the migration of nocturnal birds. While this primarily affects perching birds such as thrushes and warblers, it also impacts ducks, geese, swans, sandpipers, and plovers.
Most humans struggle to detect
magnetic fields, only witnessing them when they create aurora-like phenomena in the skies. Birds, in contrast, like sea turtles, trout, and many other organisms, have developed organs sensitive to Earth's magnetic field.
With no equivalent of a Bird-Map app at their disposal, many species heavily rely on their geomagnetic sense to navigate over long distances during their migratory cycles. However, solar outbursts and other space disturbances frequently disrupt Earth's natural magnetic fields, leaving them without a dependable compass to guide them.
Data collected from US Doppler weather radar stations and ground-based magnetometers have revealed that 9-17% fewer birds migrate during these space weather events in the spring and autumn. Birds daring to venture out at night face substantial challenges in navigating with their unreliable compasses, particularly as autumn brings a host of visibility-reducing overcast weather.
High geomagnetic disturbances not only reduce the migration intensity (the number of birds within each migrating group) but also cause disoriented birds to drift aimlessly with the wind. The study found that birds migrating thousands of kilometres across the US Great Plains during strong solar storms in the fall put in only three-quarters of the effort to battle crosswinds and often end up lost.
The
Sun is gradually approaching the peak of its 11-year solar activity cycle, and it is already more active than usual. During its peak, it can unleash particle storms that overload Earth's satellites, radios, and power grids. As we've just learned, these storms can wreak havoc on birds' journeys. Since migration is essential for birds to find food, breed, and protect themselves from extreme weather, magnetic disruptions can have severe consequences for these hardworking organisms and prove fatal for many species.
The findings of this research have been published in the
Proceedings of the National Academy of Sciences and can be accessed
here.
