Migratory birds and Earth’s Magnetic field

Migratory birds and Earth’s Magnetic field

Subject: Environment

Section: Msc

Context: Disturbances in Earth’s magnetic field may be responsible for stranded migratory birds says the study.

More on the News:

• 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.
• 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’s invisible 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.
• Ending up in unknown territory could potentially be fatal for birds as they may find it challenging to find suitable food or habitat.
• On the other hand, it could also lead birds whose traditional habitats have changed due to climate change to more conducive homes, leading to range expansion.
• Even when other factors like weather play a role, incidences of vagrancy among the captured birds and geomagnetic disturbances coincided strongly during spring and autumn migration. The correlation was especially pronounced during the autumn migration.
• Though the study was conducted only on birds, its results could help researchers understand the reasons why other migrating species such as whales get stranded far from their usual domain.