Lassie Come Home: here’s how dogs manage to find their way back in unknown territory
Everyone is aware of the phenomenal noses of dogs. An additional and hitherto unknown sensory talent has been hypothesized in a recent study: a magnetic compass. It seems that this feature allows dogs to exploit the Earth’s magnetic field to calculate shortcuts in unknown territory.
The navigation skills have been studied less in dogs than in migratory animals such as birds. It has already been speculated that dogs – like many other animals, and perhaps humans too – are capable of sensing the Earth’s magnetic field. In fact, in 2013, it has been shown that they tend to orient themselves north-to-south while urinating or defecating. Since this behavior is involved in the marking and recognition of the territory, it was therefore hypothesized that this alignment would help the dogs to understand the position in relation to other points. However, the new study suggests that this perception also plays a fundamental role in navigation.
How was the study performed? Initially, cameras and GPS trackers were installed on four dogs, then taken on a trip to the forest (in an area unknown to them). The dogs ran away to a distance of 400 meters (on average) to follow the smell of another animal. The GPS signal showed two types of behavior during return trips. In one, called tracking, the dog retraced the original route, presumably following the same smell. In the other, called scouting, the dog returned on another route. How did the dog go back to his owner following an alternative path?
Studying in detail the scouting of dogs, a peculiarity was noticed: before going back, the dog stopped and ran for about 20 meters along a north-south axis. This behavior could consist in the alignment along the magnetic field, in order to be able to orientate. The study was expanded to collect confirmations of what was hypothesized. 223 scouting cases were analyzed (with an average distance of 1.1 km). In 170 of these trips, the dogs ran about 20 meters along a north-south axis, before going back. These animals tended to return to the owner by following a more direct path than when they did not follow this behavior. The researchers concluded that dogs remember the starting position and use an interior magnetic compass to elaborate the most direct way-back route.
Because working with animals is never easy, it is possible to be 100% sure of a conclusion, only when all other hypotheses are discarded. For this reason, the next experiment will consist of installing magnets on the collars of dogs, in order to disturb the local magnetic field and see if it will somehow hinder their navigation ability.