The ability of birds to follow the same and exact migratory path without fail is attributed to their use of the Earth's magnetic field. This has long been known for over 50 years now.
A recent study found, however, that the birds' synchronized navigation can go haywire because of human-induced reasons, particularly the electromagnetic waves emitted by radios. This is according to a seven-year long investigation by a group of scientists at the University of Oldenburg.
The team, led by professor and biologist Henrik Mouritsen, discovered that frequencies from AM radios disrupt the innate navigation skills of birds, which may further worsen the age-old problem of population decline in these free-flying migratory species.
"In our experiments we were able to document a clear and reproducible effect of human-made electromagnetic fields on a vertebrate. This interference does not stem from power lines or mobile phone networks," Mouritsen said.
The electromagnetic signals mixed with the Earth's natural magnetic compass disrupted the migratory birds' track as they fly off for winter and back for spring. These are mostly found in office tools such as printers and computers and home appliances such as refrigerators and lights and the cities are most critical disturbances in the path of migration.
But it was not until three years after that Mouritsen discovered the problem undermining the setback they had in the beginning, which resulted in the extensive study that can be now found in the recent issue of the journal Nature.
After they moved in to Oldenberg, Mouristen's birds, which he uses for research, began acting weird. The European robins he brought in seemed to get lost during the migration season. Baffled and frustrated over the strange actions of his birds, he tried various things to keep them in tiptop shape. But to no avail. A colleague then proposed if they could surround the hut with aluminum.
Desperate to make things work, they ended up taking the suggestion. As luck would have it, the birds finally pointed to the right direction as they would in migration season. The plates, which had metal rods attached to them and planted in the soil of the hut, "grounded" the magnetic disturbance that came from the gadgets found near the hut. Mouritsen dubbed this noise as "electrosmog."
"Over the course of seven years we carried out numerous experiments and collected reliable evidence, in order to be absolutely certain that the effect actually exists," Mouritsen remarked.