A new study found out that the signals emitted by electronic devices are making migratory birds lose their pathways.
Biologists previously thought that migratory birds use Earth's magnetic field to establish their pathways. Researchers from the University of Oldenburg and Oxford University, spearheaded by Prof. Henrik Mouritsen, conducted an experiment to test this belief.
They put the robins inside the wooden huts while locked in their orientation cages then covered the huts with aluminum. They were then surprised that the orientation problems of the birds disappeared. Prior to the experiment, these birds were unable to use their magnetic compass which researchers believed was caused by their exposure to the AM radio signals produced by the electronic devices within the campus.
"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. The effects of these weak electromagnetic fields are remarkable: they disrupt the functioning of an entire sensory system in a healthy higher vertebrate," Prof. Mouritsen said in a press release.
The researchers concluded that exposure to within 2 to 5 megahertz of electronic noise generated by humans can disrupt the magnetic compass of the migratory birds. This is despite the intensity being much lower than the harmful level set by the World Health Organization.
"Our measurements of the interferences indicated that we had accidentally discovered a biological system that is sensitive to anthropogenic electromagnetic noise produced by humans in the frequency range up to five megahertz," Mouritsen added.
The experiments were repeated many times and created the same results. In addition, they also found out that the effect of the electromagnetic disruption is localized. This may explain why migratory birds often go to rural areas instead of the urban areas where many are using electronic devices.
Further details of this finding were published on the May 7 issue of Nature.
