Disturbances in Earth’s magnetic field may be responsible for stranded migratory birds
The Hindu
The study could help researchers understand why other migrating species get stranded far from their usual domain.
It is now the season of bird migration when thousands of winged visitors fly astoundingly long distances to nest, enjoy abundant food supply and seek shelter in warmer climates. In India, enthusiastic bird watchers eagerly wait for the yearly migration to catch a glimpse of exotic species that arrive in droves to the subcontinent.
But how do migrating birds, who traverse the same route year after year, go astray?
A new study published by Scientific Reports has found that the Earth’s magnetic field may be partially to blame for birds losing their way when migrating- also referred to as avian vagrancy.
Though birds sometimes lose their way due to storms, cloud cover or dense fog, an increasing number of studies have suggested that they also rely on the Earth’s magnetic field to navigate, especially when flying long distances. “There’s increasing evidence that birds can actually see geomagnetic fields,” said Morgan Tingley, co-author of the study and an associate professor at the University of California, Los Angeles, in a press release.
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Scientists analysed 2.2 million records of birds constituting 152 species that were captured and then released between 1960 and 2019, and found that the birds’ ability to use the geomagnetic field was hampered when there were disturbances in the magnetic field.
The geomagnetic field, or Earth’sinvisible magnetic field which runs from the North Pole to the South Pole, is highly influenced by a number of internal and external factors. When Earth’s magnetic field is disturbed, it would leave the birds with ‘distorted maps’ which would land them in completely different locations, Dr Tingley said.