When migrating birds get lost, they can ‘read’ the signature of the Earth’s magnetic field well enough to find their way once again, a study has revealed.
Researchers from the UK exposed Eurasian reed warblers to a fake magnetic signature, thousands of miles from their usual path, to see how they would react.
Despite all the other cues from their actual location, the birds readied to fly off as if they were in the location that matched that of the simulated magnetic field.
This proves that birds use the geomagnetic field as their primary method of navigating in unfamiliar locations, allowing them to course correct if needed.
In their study, the researchers took adult Eurasian reed warblers who were already familiar with their migration route and its general magnetic signatures and held them in captivity for a short period of time.
When the birds were released back into the wild at a site in Austria, the team exposed them to a simulation of the Earth’s magnetic signature from a location in Russia some thousands of miles outside of the creature’s natural migratory corridor.
Despite experiencing all other sensory clues about their actual location, including its sights, smells, sounds and starlight, the birds still showed the urge to begin their journey as if they were in Russia, as indicated by the fake magnetic signature.
The team noted that the birds would prepare themselves to fly off in the exact direction that would have led them back to their customary migratory path, had they really been in Russia rather than in Austria.
Following the study, all the birds were released back into the wild.
The full findings of the study were published in the journal cell.com.