Mystery Solved: Animals Ability To Sense Earth’s Magnetic Field

Scientists have discovered the sensor that allows animals to sense the Earth's magnetic field - a feat that, until now, had left scientists baffled.

A team from the University of Texas in Austin have found an antenna-like structure (or “sensor”) in the brain of a worm, that allows it to detect a magnetic field.

Found in a simple worm named Caenorhabditis elegans (or C. elegans), the sensor is a neural ending that protrudes from the brain.

Scientists are hopeful that the discovery of this sensor will also be found to exist in other animals who also appear to sense Earth’s magnetic field, thus giving them a greater understanding of magnetosensation in animals. reports:

The study’s lead author is Andrés Vidal-Gadea, a former postdoctoral researcher in the College of Natural Sciences at UT Austin, now a faculty member at Illinois State University; he also noted that worms are just some of the animals that have a way to detect magnetic fields – animals as diverse as geese, sea turtles, bees and wolves are known to navigate using the Earth’s magnetic field. Vidal-Gadea chose to focus on worms, and he was successful.

“I’m fascinated by the prospect that magnetic detection could be widespread across soil dwelling organisms,” said Vidal-Gadea.

They used hungry C. elegans worms and studied their behavior. They initially noticed that they generally tend to probe for food downwards, but when a coil was turned on and induced a strong magnetic was created, the worms would simply dig around randomly. They then moved on to study the worm’s neurons, and found the sensor.

In 2012, scientists from Baylor College of Medicine announced the discovery of brain cells in pigeons that process information about magnetic fields, but they couldn’t find the exact structure which acts like a sensor.

“It’s been a competitive race to find the first magnetosensory neuron,” said Pierce-Shimomura. “And we think we’ve won with worms, which is a big surprise because no one suspected that worms could sense the Earth’s magnetic field.”