Grazing cattle often line up with Earth's magnetic field unless high-voltage lines are nearby

Last year, researchers used Google Earth to discover that cows and deer resting or grazing in pastures faced either magnetic north or south, indicating that the animals have an internal magnetic compass. (BBC photo) Hynek Burda and his colleagues at the German University of Duisburg-Essen then decided to see if high-voltage power lines, known to change the magnetic field of surrounding areas, altered this pattern. They did.

"Resting and grazing cows and deer do not show the usual north-south body alignment when they're close to power lines. Instead, they position themselves in random direction," Nell Greenfieldboyce reported for National Public Radio. "Farther away from the power lines, cows and deer again begin to show the usual north-south alignment." With power lines that run east to west, however, the cows and deers line up east to west.

"It is clear, if the animals change their behavior, there have to be some changes in the brain, on the cellular level, on the molecular level, and so on," Burda says. "That is what we want to study now." The study's findings were published in Proceedings of the National Academy of Sciences. (Read more)