In 2008, a team of researchers studying deer and cattle found something a little unexpected. Both animals, when grazing or resting, appear to align their bodies in the north-south direction.
“Farmers and attentive nature and countryside observers know that most cattle and sheep, when grazing, face the same way,” the team explained in their study. “The farmers’ wisdom and experience indicate that cattle face into the wind, whereas sheep face away from the wind; the animals expose the maximum body surface area to the sun when sun basking in cold but sunny times of the day.”
Despite knowing that these animals tend to align their direction when grazing, there was little scientific investigation as to why. In their study, the team reviewed Google Earth satellite images of cows grazing all over the world, observed roe deer as they grazed and rested, and analyzed the body prints left in the snow by red and roe deer. Attempting to account for factors such as wind direction and the position of the Sun in the sky, the team nevertheless found that all these animals appeared to align themselves along the magnetic north/south line in statistically significant numbers.
“Because climatic factors like wind, sun, or temperature were apparently not common directional key factors explaining ubiquitous alignment, we conclude that the magnetic field is the only common and most likely factor responsible for the observed alignment,” the team wrote. “Our analysis of cattle at localities with naturally high positive and negative declinations clearly provides the crucial proof in favor of the Earth’s magnetic field being the responsive cue.”
Though a strange result, it’s not entirely out of the realms of possibility. Some animals, generally smaller than cows and deer, have been shown to have magnetoreception, or the ability to perceive the Earth’s magnetic fields. In fact, it’s surprisingly common, and particularly useful in migratory birds, likely aiding navigation.
In a follow-up study, the team believed they also found evidence that the “orientation behavior” could be disrupted by extremely low-frequency magnetic fields generated by high-voltage power lines.
The team stressed that the mechanism of the orientation behavior is unknown, though there are a few suggestions.
“For instance, the radical pair hypothesis proposes an intimate coupling of magnetic sensing with vision. According to this hypothesis, magnetic fields are perceived as visual patterns, which are dependent on both field direction and intensity,” the team wrote in their study. “Thus, it is conceivable that the oscillations of the direction and intensity resulting from the [Earth’s magnetic field] and [alternating magnetic field] interaction may blur magnetically modulated visual patterns and, in turn, compromise or disrupt magnetic compass orientation.”
While an interesting idea, you may not want to throw away your compass in favor of a much more enjoyable cow compass just yet. A more recent study, which looked at 34 cows and attached strong neodymium magnets to their collars, found that they showed no signs of directional preference, whether they were wearing the magnet or not. In another part of the study, they conducted 2,428 daytime observations of 659 resting cattle throughout the day in Portugal, excluding when it was hottest, finding that the cows preferred to face south east.
Rather than possessing magnetoreception, the team believes that it is more to do with the direction of the Sun, concluding that the previous studies may have been skewed by looking at Google Earth images taken on sunny days.
“We found a significant correlation between the animal’s orientation and the direction of the sun, minimizing sun radiation on the animal’s body, similar to what was observed in horses,” the team wrote in their discussion. “Indeed, if most views were made on cloudless sunny days, then the animals were possibly reducing their body exposure to the sun. We thus believe that the cattle’s reported south-north alignment observed in earlier studies could perhaps, at least in part, be attributed to thermoregulation, possibly overriding a magnetic alignment. Similar sun-reducing behaviour has been observed in springbok and in black wildebeest, and was demonstrated to be linked to thermoregulation in those studies.”
In short, further, more comprehensive study may be needed to find out why cows tend to align while grazing and resting, and you probably shouldn’t use them instead of a compass just yet.
Source Link: Do Cows Really Align With The Electromagnetic Field Of The Earth?