Cattle magnetic compass found with Google Earth
A team of biologists from Germany and the Czech Republic made a surprising discovery: domestic cows and wild deer apparently have the ability to sense Earth’s magnetic field. But the most surprising aspect of the work relies on the tools and methodology employed. No expensive high-tech devices or extenuating field trips were involved. This five-people team simply browsed the world’s surface using Google Earth to look for cattle and deer herds and record each individual’s orientation. Internet-connected computers, statistical calculations and lots of patience constituted the arsenal involved in this surprising discovery.
The team analysed 8,510 cows in 308 pastures across the globe, and 2,974 grazing and resting red and roe deer at 241 localities. They found that most animals align their body axes in roughly a north–south direction. Direct observations of roe deer revealed that animals orient their heads northward when grazing or resting. The investigators notice that “this ubiquitous phenomenon does not seem to have been noticed by herdsmen, ranchers, or hunters”. To see if wind and light conditions, rather than the magnetic field, could be the factor determining the body axis orientation, they carefully analysed the body orientation of cattle from localities with high magnetic declination where the magnetic north is a better predictor than the geographic north. based on statistically significant data, they concluded that these large mammals indeed align their bodies following the magnetic direction. This fantastic discovery open new avenues for the study of magnetoreception in general and certainly will have significance for applied ethology and neuroscience.
Source: http://www.pnas.org
