Migrating birds have a keen sense of direction, but solar winds make them lose their way

With the help of the Earth’s magnetic field, migratory birds easily navigate to their summer or winter destination, even in the dark or in bad weather conditions. It’s a great achievement, but there’s one thing that messes things up: the solar wind. Then the GPS in the migrating bird’s head goes crazy.

Researchers from University of Michigan They processed huge amounts of data They have been collected over the past decades by weather radar stations and magnetometers – equipment that measures the strength of local magnetic fields from the Earth. The US team began looking for a possible link between geomagnetic disturbances and changes in bird migration behavior during spring and autumn nights.

Global Positioning System (GPS) for birds
Scientists found that during extreme weather events in space, there were 9 to 17 percent fewer migratory birds in the sky, in both spring and fall. Birds that chose to traverse the distance clearly had more difficulty navigating. Especially in the fall, when there were a lot of clouds, they had a hard time.

“Our findings show how much animals depend on signals from their environment, including signals that we humans cannot pick up, such as disturbances in the Earth’s magnetic field,” says lead researcher Eric Jolson Castillo. “These magnetic signals influence the movement patterns of large groups.” from animals”.

Extreme space weather
The Earth’s magnetic field is regularly disturbed by solar flares, also called solar flares, solar storms, or solar eruptions Coronal mass ejection (CMEs). The effect of this can sometimes be seen as the northern lights, but it also has a number of less beautiful consequences. Solar winds are capable of disrupting satellite communications, human navigation systems and power grids, but little is known about how extreme space weather affects the sensations of birds, sea turtles and other animals navigating Earth’s magnetic field.

However, recent research has shown that more migratory birds have lost their way during some recent solar storms. But the new study relies on a dataset of American migratory birds spanning at least 23 years. The central flyway over the Great Plains of the United States from Texas to North Dakota and back, which is more than 1,600 kilometers long, has now been mapped over these years using 37 radar stations.

Huge data sets
Mainly songbirds, such as thrushes and warblers, attempt to cross at night. There are also wading birds, such as sandpipers and plovers, and waterfowl such as ducks, geese and swans that migrate. The researchers combined all data received from radar stations with the outputs of magnetometers, which tracked the maximum change in the Earth’s magnetic field per hour.

“The biggest challenge was converting this large data set – years and years of observations of the Earth’s magnetic field – into an index of geomagnetic disturbances for each radar station,” explains space scientist Daniel Welling. “We had to do everything we could to ensure the quality of the data and the validity of the final product.” All data was processed taking into account all known weather influences, temporal variables such as night time, and geographical variables such as the latitude and longitude in which the birds are located.

Widespread impact on migration dynamics
“We found strong evidence that there are fewer migratory birds in the sky during periods of high geomagnetic turbulence,” researcher Ben Wenger said. “Our results provide an ecological context for decades of research into the mechanisms underlying magnetoreception in animals. We have demonstrated that extreme space weather has a widespread impact on the migration dynamics of entire migratory bird populations.

Very cloudy fall nights and extreme satellite weather
Migratory birds that are still in the air during autumn solar flares also appear to be carried by the wind much more than usual. So-called “stressed flying” against the wind occurred a quarter less frequently on cloudy autumn nights during strong solar winds. According to scientists, this is a clear sign that magnetic imbalance is causing navigation problems.

“We have shown that fewer birds migrate during solar storms and that birds that do migrate have more difficulty finding their way, especially during fall nights with heavy cloud cover,” Jolson-Castillo said. “As a result, they make less effort to fly upwind and allow themselves to drift more with the wind.”