Somehow, cattle seem to know how to find north and south, say researchers who studied satellite photos of thousands of cows around the world. Most cattle that were grazing or resting tended to align their bodies in a north-south direction, a team of German and Czech researchers reported. And the finding held true regardless of what continent the cattle were on, according to the study led by Hynek Burda and Sabine Begall of the faculty of biology at the University of Duisburg-Essen in Germany. “The magnetic field of the Earth has to be considered as a factor,” the scientists said. This challenges scientists to find out why and how these animals align to the magnetic field, Begall said. “Of course, the question arises whether humans also show such spontaneous behavior,” she said, adding, and what “consequences does it have for their health.” “If they have evidence suggesting that mammals are using magnetic fields to orient their movements, this is very cool,” said Mark A. Willis, an associate professor of biomedical sciences at Case Western Reserve University in Cleveland. Willis, who was not part of the research team, added, “We have only in the last few years begun to understand the mechanisms underlying magnetic field orientation in birds and other smaller animals.” Indeed, it's small animals that led to this study, Begall explained. They were researching the magnetic field effect on African mole-rats. “At one point last year the question came up whether large animals could also sense the Earth's magnetic field or not. But of course, it is difficult, or maybe impossible, to do these studies in the lab,” she said. “So, the idea arose to look for other large mammals like cattle, and Hynek Burda was fascinated when he recognized that cattle could be found on Google Earth satellite images.” With satellite images they could tell the north-south orientation of the animals, but not whether an individual cow was facing north or south. You have to get closer to tell which end is which. Now the researchers are moving on to study sheep, goats, horses, wild boar and some further deer species, Begall added. What the benefit could be for cows, however, remains a mystery. It might help them find their way home, experts said, or perhaps it is simply a vestigial sense that is no longer used for any purpose. Furthermore, the authors noted, no one has examined cows or deer to determine whether their brains contain magnetic particles. Experts acknowledged that the research almost certainly has no practical applications.
