Discovery: Dogs Can Navigate Based on Earth's Magnetic Field

Dogs have long been known for their keen sense of smell, but that's not their only special ability. They also can sense Earth's magnetic field, allowing them to calculate shortcuts when encountering unfamiliar terrain, a new study suggests.

Dogs have a lot of interesting abilities including the ability to navigate using
the Earth's magnetic field

This is the first time this ability has been detected in dogs, says University of North Carolina biologist Catherin Lohmann. Compared with other migratory animals such as migratory birds, research on the navigation ability of dogs is still very limited.

Before then, there were clues about the ability of dogs and many other animals to sense the Earth's magnetic field. In 2013, ecologist Hynek Burda of the University of Life Sciences in Prague, Czech Republic, studied the subject for 3 years and demonstrated that dogs tend to be north-facing males when they urinate or defecate. Since this behavior is associated with marking and recognizing territory, Mr. Burda reasoned that this trait helps the dog determine its position relative to other locations. However, these fixed points are linked differently than navigation.

For the new study, one of Mr. Burda's graduate students, Kateřina Benediktová, fitted four dogs with cameras and GPS trackers and led them into the woods. The dogs would then be released to chase the animal's scent over an average distance of 400 meters. The GPS results showed that the dogs exhibited two behaviors on their way back to their owners: the dogs would follow and return the same way, or return along an entirely new path without re-tracking the old road.

Hounds participating in the experiment were fitted with video cameras and GPS
to locate the way

Later, when Benediktová gave these data to Mr. Burda, he noticed another strange feature: while he was doing reconnaissance, the dog would stop and run about 20 meters along the north-south axis, then come back and start all over again navigation. When displayed on a map, these short runways look like lines running along the magnetic field, but Benediktová remains unsure because of a lack of data.

So the next test was done with 27 dogs and hundreds of runs, spanning over 3 years, and a full analysis of 223 trail runs with an average of 1.1 km each return trip. The researchers detected the behavior of stopping before a turn and running north-south for about 20 meters on 170 trips by the dogs. Each time, the animal tended to return to its owner in a more straight line.

The paths of the dogs are marked

Mr. Burda thinks the most likely explanation is that running along a north-south axis helps dogs determine where they are. Mr. Roman believes the factor behind this behavior is the dog's ability to remember the original direction and use the magnetic field as a reference to find the fastest way home.

The design of the magnetic field experiments is complicated because it is difficult for animals to rely on a single sense, says Adam Miklósi, a researcher who studies canine behavior at Eötvös Loránd University.

Looking ahead, Mr. Burda and Benediktová will take a different approach. In the new experiment, they will place a magnet on the dogs' collars to disrupt the magnetic field in space to see if it interferes with their ability to navigate.

Mr. Miklosi said it was not surprising that dogs could use magnetic fields to navigate, as the ability appeared to have been present in their ancestors and in any mammal that had to navigate the oceans.