Dogs seem to have an awful lot of ritual before hunkering down and soiling the sidewalk. It's not uncommon to see a dog owner—plastic bag in hand—rolling his eyes as his furry companion sniffs and spins, getting just so before hunkering down to do the least considerate thing possible.
But for whatever its worth, all that spinning is far from arbitrary. What dog owners witness is a small and furry version of the aurora borealis and a link between species and environment that's as holistic and beautiful as a dog pooping can be. A team of Czech and German researchers found that dogs actually align themselves with the Earth's magnetic field when they poop.
Proving at least that they're really devoted to their work, the researchers measured the direction of the body axis of 70 dogs from 37 breeds during 1,893 defecations and 5,582 urinations over the course of two years, and found that dogs "prefer to excrete with the body being aligned along the North-south axis under calm magnetic field conditions." They fittingly published their results in the journal Frontiers in Zoology.
You might wonder why dogs bother to do this, and uh, so do the researchers.
It is still enigmatic why the dogs do align at all, whether they do it 'consciously' (i.e., whether the magnetic field is sensorial perceived (the dogs 'see,' 'hear' or 'smell' the compass direction or perceive it as a haptic stimulus) or whether its reception is controlled on the vegetative level (they 'feel better/more comfortable or worse/less comfortable' in a certain direction). Our analysis of the raw data (not shown here) indicates that dogs not only prefer N-S direction, but at the same time they also avoid E-W direction.
This isn't the only example of animals seemingly sensing the Earth's magnetic field. Birds, turtles, and fish are known to use magnetic guidance while migrating. Cattle and deer are known to graze on a north-south axis—as with defecating dogs, this is magnetic north, not the geographic one. Some bats navigate using a magnetic compass and given the large ranges of the dog's closest relatives in the wild, wolves, scientists suspected that canines might also sense the magnetic field.
But this was perhaps the first time that magnetic sensitivity was proven in dogs, and it was also the first time that a predictable behavioral reaction to the fluctuations in the magnetic field—magnetic storms, often as resulting from solar flares—was proven in a mammal.
If you're out walking your dog later, and he sidles up and pees on a tree facing east-west, don't be terribly surprised. The magnetic consciousness was observed only in dogs off leash, in the middle of a field. All things considered, the owner matters more to the dog than the Earth's magnetic field; a nice little ego-booster that you'll need as you bend over to pick up warm dog droppings.