Weird Magnet Fact: Animals Sense Earth’s Magnetic Field
Unless we have magnetic implants or are cyborgs, humans don’t really detect the Earth’s magnetic field. Sure, we know that it exists thanks to the contributions from various scientists like William Gilbert and Walter M. Elsasser. But, we don’t naturally sense it. Yet, certain animals do sense the Earth’s magnetic field and even use it to guide them like a GPS, or navigation system. The first recorded observation that suggested animals have a magnetic ‘sixth sense’ occurred in 1957 when a researcher in Germany noticed that robins in a cage were getting restless during the migratory season. Since then, a number of studies have been done on various species to test whether or not they had the same magnetic detection abilities.
Here are a few animals that some scientists believe can sense the magnetic field and how they use it.
As you may have guessed, many migratory bird species are thought to have the power to sense the Earth’s magnetism. In fact, some researchers think that the magnetic field is vital to birds when they migrate, because it helps direct them in their travels.
These creatures of the night use an internal magnetic compass to navigate in the dark. However, a recent study revealed that they couldn’t set their compass without some polarized light at sunset. Sometimes the magnetic field shifts and is not an absolutely accurate GPS on its own, so bats and even birds will use other signals in nature like light to help with navigation.
Even insects like the monarch butterfly need the magnetic field when migrating. For them though, the magnetic compass is more of a backup navigation. First, they use light but on overcast or cloudy days, they rely on magnetism. A recent study in Nature Communications showed that monarch butterflies will sometimes use changes in the magnetic field as a way to orient themselves, rather than just relying on the position of the magnetic poles.
The way that researchers believe that dogs use the magnetic field may sound so bizarre that it is hard to believe. However, after a study, released in Frontiers in Zoology, zoologist Hynek Burda of Germany’s University of Duisburg-Essen, reports that dogs do their territorial marking in line with the North and South magnetic poles. In other words, they sense the magnetic field and urinate accordingly.
Certain shark species like the great white have been said to be able to detect magnetic fields. The scientists that study the phenomenon have attributed the magnetic power to the sensory organs called ampullae of Lumpini, that line the heads of some sharks. Researchers are using the sense to potentially create shark-friendly beach barriers with neodymium magnets.
When we think about the number and diversity of animals that can detect and use the Earth’s magnetic field, it almost makes us wonder why humans do not. Perhaps, we once did and had evolved so much that we simply lost the ability. As far as we know there is nothing to suggest that we did, but it might be neat to have the extrasensory ability. Even though, we can’t do it on our own, we can still marvel at animal’s ability to connect with the Earth’s magnetic field and navigate from it.