Using Earth’s Magnetic Field To Navigate

Do you ever go into the woods and use a compass to find your way around the forest? The compass has a needle that aligns with the earth’s magnetic field to point north/south. You are either really good at it (think scouts) or terrible like me. I still don’t get how they work. So think about sea turtles using a compass to find their way thousands of miles to lay eggs on the same beach where they were born.  Of course, they can’t read compasses but they sense the earth’s magnetism or pull. It is a mind-boggling feat.

So what other animals use the earth’s magnetic field to navigate?  Well, think about any animal that flies or swims long distances. Monarch butterflies, salmon, whales and migratory birds all use magnetism to migrate or find a breeding site. But have you ever heard of magnetism being used to pinpoint food? So far only one animal appears to use the earth’s pull to locate and capture their prey. They use it to judge distance, depth and direction. But how can that be? They can’t read a compass. So what animal possesses this superpower? The fox, and only the fox! To learn more about foxes, read our Explore & Learn “Red Fox”.  

One, Two, Three

First, the fox listens for the mouse. The fox then aligns itself with the angle of the sound waves. It is thought there is a protein in their eyes that causes a shadow when they are in the correct alignment with the earth’s magnetic field. When they align to the north, they successfully pounce on their prey 74% of the time. If they align in any other direction, they are only successful 18% of the time. So while other animals use the earth’s magnetic field to judge distance, foxes use it to judge distance, depth and direction. Pretty darn cool. A true superpower.

Now watch the fox dive in slow motion.