A German wirehaired pointer walking on a field. Photograph by Juniors Bildarchiv, Alamy

Dogs don’t need a compass: Your best friend can sense Earth’s magnetic field, say researchers who report that dogs preferentially align themselves facing north or south to do their business.

Dogs are well known for their excellent sense of smell and their keen sense of hearing. The team, led by zoologist Hynek Burda of Germany’s University of Duisburg-Essen, reports in the journal Frontiers in Zoology that our furry friends prefer to relieve themselves or do their territorial marking while facing north or south. That implies they are sensing the Earth’s magnetic field.

“They do so, however, only when the magnetic field is calm—something [that] we ourselves are not able to recognize unless we look on the actual daily magnetograms released by geomagnetic observatories,” says Burda.

The new findings have important implications in our understanding of magnetoreception in mammals. Previous work by Burda and his team showed that cows, deer, and foxes are sensitive to Earth’s magnetic field, but this is the first study showing a mammal not only being able to sense it, but also to exhibit a specific behavior in response to natural magnetic field variations.

The findings are also appealing for another reasons, Burda adds: “To many dog owners who know about the good navigation abilities of their protégés, the findings might not come as a surprise, but rather as an explanation for the ‘supernatural’ abilities—although it is not clear to the researchers what the dogs might use their magnetic sense for.” (The researchers intend to set up a university website for dog owners who wish to test their own pet’s abilities; the site is expected to be up by January 6.)

Doing Their Business



In the two-year study, the researchers analyzed the body orientation of 70 dogs from different breeds as the dogs relieved themselves. At first look, their analyses showed no clear pattern of dogs preferring any particular orientation to do their business.

However, when the researchers took into account the naturally occurring variations of Earth’s magnetic field and factors like the time of the day, the position of the sun, and wind direction, the doggy sixth sense was revealed.

“The emerging picture of the analysis of the categorized data is as clear as [it is] astounding: Dogs prefer alignment along the magnetic north-south axis, but only in periods of calm magnetic field conditions,” said Burda.

In other words, under stable magnetic conditions the dogs would always poop and pee while facing either north or south. This provides convincing evidence that dogs can sense magnetic fields and are sensitive to even small magnetic-field variations, say the researchers.

New Answers, More Questions

Future research will focus on two basic questions: What are dogs are doing with this ability, and how are they doing it? It also raises questions about how magnetic storms affect an animal’s behavior.

The results may provide an explanation as to why previous research on magnetoreception had mixed results. Calm magnetic-field conditions occurred only 30 percent of the time during the study. So future research will need to correct for these variations in order to obtain reproducible results. This also means that earlier researchers might consider reanalyzing their data to take into account variations in the magnetic field.