Morgan Tingley: The European Times—Magnetic Mishaps: Disturbances in the Earth’s Magnetic Field Could Lead Migrating Birds Astray

Earth’s magnetic field, which runs between the North and South Poles, is generated by several factors, both above and below the planet’s surface. Decades’ worth of lab research suggests that birds can sense magnetic fields using magnetoreceptors in their eyes. The new UCLA study lends support to those findings from an ecological perspective.

“There’s increasing evidence that birds can actually see geomagnetic fields,” said Morgan Tingley, the paper’s corresponding author and a UCLA associate professor of ecology and evolutionary biology. “In familiar areas, birds may navigate by geography, but in some situations, it’s easier to use geomagnetism.”

But birds’ ability to navigate using geomagnetic fields can be impaired when those magnetic fields are disturbed. Such disturbances can come from the sun’s magnetic field, for example, particularly during periods of heightened solar activity, such as sunspots and solar flares, but also from other sources.

“If the geomagnetic field experiences disturbance, it’s like using a distorted map that sends the birds off course,” Tingley said.

Lead researcher Benjamin Tonelli, a UCLA doctoral student, worked with Tingley and postdoctoral researcher Casey Youngflesh to compare data from 2.2 million birds, representing 152 species, that had been captured and released between 1960 and 2019 — part of a United States Geological Survey tracking program — against historic records of geomagnetic disturbances and solar activity.