May 9, 2014
Electronic Signals May Disrupt Bird Migration
redOrbit Staff & Wire Reports - Your Universe Online
Electromagnetic noise from AM broadcast signals (or "electrosmog") could be interfering with the migratory flight paths of birds by disrupting the animals' "internal compass,” German researchers reported this week in the journal Nature.
"At first, I was highly skeptical that this could be the explanation. But if you have seemingly unlikely effects then the proof needs to be much stronger - and that is why we have done so many experiments over seven years and it has taken a long time before we were confident to come out with this to the public,” said lead researcher Professor Henrik Mouritsen from the University of Oldenburg in Germany, in an interview with BBC News.
Birds are capable of performing extraordinary acts of navigation, with some migrating half way around the world.
It is believed that the birds’ built-in magnetic compass, which senses the Earth's magnetic field, helps them accomplish this task.
Mouritsen said he accidentally stumbled across the fact that low frequency waves could be interfering with this compass while studying European robins.
"The basic experiment we do in bird navigation research is that we put birds into an orientation cage," he said, an experiment that has generally worked for 40 years in a number of locations. "But here in Oldenburg, we couldn't get that basic experiment to work until one day we got the idea to screen these huts on the inside with aluminum plates so the electromagnetic noise was reduced about 100 times. And suddenly the birds started to orientate.”
Over the next seven years, Mouritsen and his team conducted experiments to study how the weak electromagnetic field affected the behavior of the robins, and discovered that birds exposed to electromagnetic "noise" between 50 kHz and 5 MHz lost all sense of direction.
However, when the field was blocked, the birds were able to regain their bearings.
Mouritsen noted that migratory birds flying over towns and cities, where there are more people that use electrical devices, would be most affected by these disruptions, and would likely turn to back- up navigational systems.
"The birds wouldn't be completely lost because they have three different compasses: a star compass, a sun compass and a magnetic compass, and they work independently of each other. As long as it is clear they should be fine with their sunset compass or star compass,” he explained to BBC's Rebecca Morelle.
Experts do not yet completely understand how a bird's magnetic compass works, although evidence exists that they use the quantum phenomenon of electron spin to navigate.
"A very small perturbation of these electron spins would actually prevent the birds from using their magnetic compass," Mouritsen said.
"The energies are so low in intensity that any physicists will tell you they can't have an effect on a process based on conventional physics.
"Given this effect is real, we find it very difficult to come up with an explanation that is not quantum based."
Mouritsen said the findings of his experiments might eventually cause some of the frequencies found to disrupt the birds’ navigation to be phased out.
What devices are actually contributing to this phenomenon? As Susan McGrath of National Geographic points out, "Given the measured frequencies, Mouritsen can say that these are not from cell phones or power lines—but other than that, he can't specify. The possible sources are almost endless: The Oldenburg campus alone houses everything from toaster ovens to scanning electron microscopes."