Every now and then we tell the story of a dog who comes home from far away. Of course, smell is very important for dogs, so following a familiar scent is a way for them to find their way back to their family and home. But are there other options? Is it possible that dogs can detect magnetic fields and use them to orient themselves?
It's not a completely crazy idea, since we think that birds have useful magnetic fields. Earth's magnetic field for navigation during long walks. And several species of mammals, including red foxes, deer and cattle, are thought to be able to detect magnetic fields.
There are some clues from vision of mammals. . A type of light receptor called crypto chrome 1 is thought to be important for birds' detection of magnetic fields. Research has shown that this receptor is present in the eyes of mustelids (such as ferrets and badgers), bears, and, as you might imagine, canids such as the domestic dog (Nießner et al. 2016). It has not been found in other species studied, including rats and cats.
However, there is much uncertainty about the actual action of this receptor. What if we studied the behavior of dogs to better understand their response to magnetic fields?
A few years ago, a highly publicized study shed light on the topic. They report that dogs prefer to defecate along the north-south axis, although they can also face north or south (Hart et al. 2013). Furthermore, they reported that females align with this axis during urination, but males do not. The scientists who conducted this study hypothesized that this gender difference was linked to the way in which one urinates (bending or lifting a leg).
The magnetic field Earth fluctuates considerably, and this study found that the alignment only occurred when the magnetic field was stable, but not when it fluctuated. The dogs participated in several locations in Germany and the Czech Republic.
But it's not that simple, because a recent study looked at how the dogs participated while five dogs urinated and defecated. in parks in Lyon, France, they found no evidence that they were aligned with the magnetic field (Rouviere and Ruxton, 2021). The scientists who conducted this research attempted to repeat the previous study, except that the measurements were taken by scientists, while the other study was based on observations of dog owners.
In both studies the dogs were not tied and could move freely. Rouvière and Ruxton say the park's design can influence how dogs move within it.
One thing that isn't clear is why which the dogs align with the magnet. . Field to poop in (if they do). But there is one obvious situation where the magnetic field can be useful for dogs: navigation.
It is therefore very interesting to see that a study tested whether dogs can use the Earth's magnetic field for navigation (Benediktová et al 2020). The researchers observed how hunting dogs found their owners after waiting for the dog to move away and then hiding behind a tree.
The dogs were gifted of GPS. Tracking collars and walked through a forest equipped with cameras. During this time, the owner was able to record his location using GPS, and scientists measured the dog's path and the magnetic field between the dog and the owner.
Hunting dogs the dogs were selected because they were bred to chase prey and then return, and ten different breeds participated, including a miniature dachshund and a fox terrier.
Scientists have said there are two main methods dogs can use to return to their hidden owner. Or they could return the same way they came, using their sense of smell and retracing their route back. Or they could try to explore and return across the landscape.
The following approach was the most common and was adopted by 59% of dogs; 33% used exploration; and the remaining 8% used a combination. The dogs that used the scanner were faster. These dogs made a short run along a north-south axis, which the scientists called a "compass run," before turning towards their owner.
Statistical analysis revealed that the orientation of this compass was always north-south, regardless of where the compass was located.
Scientists tried to keep account of the wind and the sun. , which can also influence behaviour. This study suggests that dogs, like birds and some other animals, have a location instinct that allows them to use the magnetic field for navigation.
Although more research is needed, this could explain the rare cases in which dogs find their way home by traveling long distances.
But dogs don't always find their way home. I'm on my way home after getting lost somewhere else. And even if they are found, they are not necessarily very far from the lost place. That's why micro chipping remains an important way to help dogs reconnect with their families!
