Dogs may be using magnetic field to navigate and find their way back home, suggests study
Dogs might be able to navigate and find a way back to their human companion from an unfamiliar terrain by sensing the magnetic field, according to a new study. The findings suggest that canines could be known for more than just their sense of smell.
Similar to how humans depend on GPS for navigation, birds and turtle use the Earth's magnetic field. Researchers have long suspected that dogs, too, carried magnetic compasses in their bodies. But studies have either been anecdotal or sparse. Canines were used to send messages during the first World War. Other studies have since added weight to the idea. What is more, scientists have also observed that dogs defecate in the north-south axis of the magnetic field.
In this new study, researchers from Czech Republic found clues that dogs could be putting their magnetic sense to use during navigation. The finding is a first in dogs, Dr Catherine Lohmann, a biologist at University of North Carolina, Chapel Hill, who studies "magnetoreception" and navigation in turtles, told Science. "I'm really quite impressed with the data," she added. Magnetoreception is the ability to detect the Earth's magnetic field.
Hunting dogs, also called scent hounds, are capable of pursuing a hunted animal for hundreds or thousands of meters and returning to humans. But how exactly do they manage to find their way back despite using novel routes in densely forested habitats is perplexing, the authors wondered.
The researchers enrolled 27 huntings dogs from 10 breeds, who were then fitted with a GPS and a camera. This allowed scientists to track the dogs' movements for three years. Two strategies could explain how dogs find their way back. Some dogs retrace their steps following their sense of smell called tracking. Others take new routes back home, which is named scouting. "While tracking may be safe, it is lengthy. Scouting enables taking shortcuts and might be faster but it requires navigation capability and, because of possible errors, is risky," the researchers said.
In their experiments, scientists examined which of the two strategies best explains navigation in dogs. They found that 59.4 percent of dogs used their sense of smell, 33.2 percent used a new route and 8 percent combined both strategies. The researchers also observed something unusual: before returning, some canines were running for about 20 meters along a north-south axis. Researchers suspect that the run could be aligned to the direction of the magnetic field. Canines that showed this behavior got back sooner to their human companions than the others.
However, the study provides clues but does not confirm magnetoreception in canines yet. According to Adam Miklósi, a scientist who studies dog behavior at Eötvös Loránd University, designing experiments is difficult as animals deploy other senses too. "The problem is that in order to 100 percent prove the magnetic sense, or any sense, you have to exclude all the others," he told Science.
Next, scientists will have to design more targetted experiments. "Our findings clearly show the importance of further research on the role and involvement of magnetic cues in canine (and more generally mammalian) navigation," they wrote in their study.
The study is published in eLife.