Magnetoreception: The Potential for a Sixth Sense

Leopold Dorilas '22

Anywhere from one to five times a day, your dog performs its somewhat sacred ritual. After turning once or twice, your dog stops and squats down to do its business. You notice that for some odd reason, your dog always seems to like facing the garbage bin in your driveway or your neighbor’s flower garden. The answer to this question lies in your dog’s ability to sense the Earth’s magnetic field and align itself along the north-south axis.

A magnet is any object that is able to produce its own invisible area of magnetic force, otherwise known as a magnetic field. All magnets have north and south poles, and the magnetic field surrounding them always travel from north to south. Therefore, when two poles have magnetic fields going in the same direction, they attract each other, and when two poles have fields going in opposite directions, they repel each other.

Magnetic substances like iron filings can help us visualize magnetic fields better, but they don’t give us a great sense of where the field’s vectors are pointing. This is where compasses come into play. If we place a series of compasses around a magnet, and we draw a line connecting their tips, we will see that they are all pointing in the direction of the way the magnetic field is moving.

Earth itself is a magnet, and its magnetic poles determine which way is north, south, east, or west. Geophysicists believe the Earth’s magnetic field is caused by the solidification of Earth’s iron core, which creates electric currents strong enough to generate a vast magnetic field.

Now how on Earth (no pun intended) are dogs able to sense which way is north so that they can position themselves accordingly when they take a relieve themselves? Magnetoreception, a sense that allows organisms to detect a magnetic field, is the key to this practice. The two most prominent theories on magnetoreception are concerned with the idea of a chemical or mechanical sensor. The first theory is based on cryptochrome, which, in the early 2000s, was thought to be the ‘magnetic molecule’ that many animals possessed. This protein is found in many animals’ eyes, and it could potentially help them see magnetic fields. Cryptochrome has already been found in dogs, wolves, foxes, chickens, and other migratory birds. The second theory is based on the possibility that animals have incredibly small traces of magnetite in their bodies, acting as magnetic receptors. Magnetite is the most magnetic naturally occurring metal on Earth, so scientists believe that magnetite is the only metal that is sensitive enough to detect tiny variations in the Earth’s magnetic field.

Magnetoreception is the key to many animals’ seemingly magical sense of navigation. It is the reason why homing pigeons can find their way home and why hatchling sea turtles are able to understand which direction they are headed in almost complete darkness. Magnetoreception has also been responsible for assisting animals in their own daily endeavors. In 2013, a team of researchers examined 70 dogs across 37 different breeds over the course of two years, collecting data on 1,893 defecations and 5,582 urinations, and concluded that dogs can sense variations in Earth’s magnetic field to align themselves. Magnetoreception is also seen to improve the accuracy of foxes’ mouse pounces, diving jumps foxes make to hunt for food below the ground. A team of scientists in the Czech Republic studied 84 foxes and around 600 mouse pounces. They found that foxes were most successful pouncing in a northeastern direction (73% kill rate), decently successful in a southwestern direction (60% kill rate), and relatively unsuccessful (18% kill rate) pouncing in any other direction.

Since other animals are able to sense where they are facing, what’s stopping me from being able to point to New York City? Well, many people speculate that us humans had this “sixth sense” and lost it overtime. Experiments surrounding magnetoreception have been conducted on humans before and yielded interesting results hinting at the small possibility of magnetoreception within us. While we still don’t know a lot about magnetoreception in humans, what we do know is that the search for information will continue as long as Earth has a magnetic field.

Works Cited

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Kirschvink, Joseph, et al. “Magnetite-Based Magnetoreception.” Current Opinion in Neurobiology, vol. 11, no. 4, 1 Aug. 2001, pp. 462–467, 10.1016/s0959-4388(00)00235-x. Accessed 8 Feb. 2022.

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Solov’yov, Ilia. “Cryptochrome and Magnetic Sensing.” Www.ks.uiuc.edu, UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, www.ks.uiuc.edu/Research/cryptochrome/. Accessed 4 Feb. 2022.

Yong, Ed. “Foxes Use the Earth’s Magnetic Field as a Targeting System.” Science, 11 Jan. 2011, www.nationalgeographic.com/science/article/foxes-use-the-earths-magnetic-field-as-a-targeting-system. Accessed 7 Feb. 2022.