BELFAST, Northern Ireland, Oct. 5 (UPI) -- A variety of research suggests migrating birds use electromagnetic maps to guide their paths north and south. But it is a difficult hypothesis to prove.
To show that electromagnetic navigation is more important than visual cues, researchers decided to manipulate the earth's electromagnetic fields along the migration route of Eurasian reed warblers traveling along the Russian coast.
Previously, the same team of researchers -- from the Queen's University Belfast, in Northern Ireland -- captured a flock of a warblers near the Biological Station Rybachy, along the Russian coast, and released the birds 1,000 miles east in Kishkinev, Russia.
Once free, the birds simply reoriented themselves and began flying in the proper direction to reach their wintering grounds.
This time around, researchers decided to warp the birds' electromagnetic field without disrupting their visual cues. A high-powered electricity-boosted magnet was installed on a coastal field site, where birds naturally congregate during their migration.
By manipulating the local electromagnetic field, scientists were able to simulate the electromagnetic characteristics of Kishkinev. The birds, once again, thought they were 1,000 miles to the east -- even though they hadn't moved an inch -- and adjusted their trajectory accordingly.
"The most amazing part of our finding is that the same birds sitting on the same dune of Courish Spit on the Baltic coast shifted their orientation from their normal migratory direction -- northeast -- to the northwest after we slightly turned current control knobs on our power supplies," Dmitry Kishkinev, a researcher with Queen's University, explained in a press release. "All the other sensory cues remained the same for the birds."
The new research, detailed this week in the journal Current Biology, is the most firm proof yet that at least some birds use an electromagnetic map to navigate.
This innate navigational sense allows the warblers to reorient themselves should they find themselves off track -- like when they're sent in the wrong direction by scientists.