If you’ve ever wondered why your dog spins around in circles before going number two, a study in December 2013’s Frontiers in Zoology may have the answer. After measuring the direction of body alignment during defecation in 70 dogs of 37 different breeds over a two-year period, scientists found that dogs preferred to set their bodies along a north-south axis, and avoided the east-west axis, while relieving themselves. However, this behavior only occurred during stable magnetic field (MF) conditions. (Researchers noted that the MF is stable for only 20% of daylight hours, which is why it’s hard to replicate findings in experiments of this nature.)
This isn’t the first time scientists discovered magnetic senses in canines. Jaroslav Červený, a Czech scientist who worked on the dog study outlined above, studied foxes for over two years and recorded their pouncing directions. In January 2011, Discover Magazine reported his findings. Red foxes preferred to pounce in a north-easterly direction, and were much more likely to successfully kill prey when they did so: they killed 78% of the time when jumping north-east, 60% when jumping in the opposite direction, and only 18% when moving in any other direction.
In the northern hemisphere, the Earth’s MF tilts down at an angle of 60 to 70 degrees below the horizontal axis. Červený believes that a fox listens to its prey, and determines where the angle of its sound matches the angle of the MF. Then the fox calculates its distance from its prey, pounces, and lands accurately on target. This “sixth sense” allows foxes to capture prey even when it’s hidden in grass or snow.
Clearly, a fox pounces in a preferred direction to ensure greater hunting success, but the reasons for dogs’ magnetic bathroom behaviors are less obvious. From the Frontiers in Zoology study:
“It is still enigmatic why the dogs do align at all, whether they do it ‘consciously’ …or whether its reception is controlled on the vegetative level (they ‘feel better/more comfortable or worse/less comfortable’ in a certain direction),”
The question of why dogs circle before going to the bathroom is, of course, much older than this recent bit of research. UC Santa Barbara scientists speculated that dogs might do this to find a clean spot, to stomp down tall grasses and weeds, to help move waste down the gut or to keep an eye on predators. In light of the red fox study, this last point is interesting. If foxes or other predators attack from a certain direction, maybe it’s adaptive for dogs to align themselves a specific way to watch out for them when in their most vulnerable position. Could this also explain why dogs often circle before lying down to sleep? Perhaps more observational studies are in order. Červený and his colleagues have done great work so far and have a clear passion for the topic, so we look forward to future discoveries on canines and their secret inner compasses.