Do cows have a sixth sense? Herd animals seem to arrange themselves according to a certain logic. On cold sunny days, many cows stand so that the warming sun rays will hit them directly. On cold, windy days, they orient themselves parallel to the wind exposing a smaller portion of their body to it.
So far so good. But where do cows choose to stand on warm days without significant wind? A team of German and Czech scientists from the University of Duisberg-Essen believe they have discovered a pattern in the animals' natural positioning: grazing and resting animals arrange their bodies along a north-south axis. Researchers published this first evidence of bovine sensitivity to the Earth's magnetic fields Monday in scientific journal PNAS (Proceedings of the National Academy of Sciences USA).
The scientists used Google Earth to observe domestic cattle, red and roe deer in all weather on five continents -- including holy cattle in India. In satellite images of 8,510 cows on 308 different pastures, 60 to 70 percent of the animals had arranged themselves along a north-south axis with their heads pointed north, according to the study. This represents "a significant deviation from random distribution," participating scientist Sabine Begall told the Associated Press in an e-mail.
But why herd animals might orient themselves this way remains uncertain. Begall hypothesizes it may have something to do with health, milk production or with preparation in case the animals are forced to migrate.
Animal orientation based on natural magnetic fields is already well-documented in the cases of birds, bacteria, ants and bats. Scientists at the University of Duisberg-Essen have also published a study showing that the African mole rat navigates underground nest building by sensing magnetic coordinates. They hypothesized that the facility to do so is centered in the rodent's corneas.
It is unclear whether humans also have a sense for magnetism. The next step for the research group will be to observe the orientation of sheep, goats, horses and other mammals for future reports.
rbn -- with wire reports.