What does it feel like to sense Earth's magnetic field? Dancing turtles revealed this secret in an engaging video.

It is difficult for people to imagine what it feels like to sense the Earth's magnetic field. However, a new study provides the first evidence that loggerhead turtles (Caretta caretta) utilize magnetic fields as a compass and also use them to determine their geographical location, as reported by Cosmos.

Sea turtles are exceptional navigators, capable of charting paths across thousands of kilometers of ocean and returning to the same feeding grounds after migration. Understanding how these animals detect and interpret magnetic fields, scientists believe, could assist ecologists in mitigating disruptions caused by artificial structures that interfere with natural magnetic signals.

According to the study's lead author, Dr. Kyle Goffort, their new discovery is essentially a significant advancement in understanding how animals perceive and utilize the Earth's magnetic field. It is anticipated that this finding may also contribute to the development of new navigation technologies in the future.

In the course of the study, scientists examined for the first time whether a migrating animal can learn to recognize the magnetic signatures of various geographical regions. For decades, it has been assumed that animals have the ability to recognize magnetic signatures; however, this new research represents the first empirical demonstration of this ability in history. Thus, the researchers were able to fill an important gap in human knowledge.

The Earth's magnetic field is present all over the globe, but it is not uniform. The intensity, tilt, and angle formed between the magnetic field lines and the planet's surface predictably change based on location. Scientists have now shown how loggerhead turtles are able to recognize, study, and memorize these magnetic signatures.

For two months, the team trained young loggerhead turtles: the animals were placed in a magnetic field adjusted to mimic the field found in a real region of the ocean. After that, the animals spent the same amount of time in a second magnetic field where they were not fed. Four months later, they exposed the loggerhead turtles again to the two magnetic fields and measured the amount of time they spent "turtling."

According to the study's authors, the turtles' behavior during the "dance" is a distinctive movement pattern exhibited by the animals while waiting for food. The team also identified some key behavioral traits of the animals, including:

• vertical body tilt;
• holding the head near or above the water;
• rapid alternating movements of the front flippers;
• spinning in place.

All these movements together are known as the "turtle dance." The study results indicate that the animals spent significantly more time in the "dance" when exposed to the first magnetic field compared to the other. Furthermore, the results suggest that the tilt and intensity of the magnetic field must correspond to the rewarded field in order for the turtles to respond.

The team believes that the animals recognized and memorized these conditions as the area where they received food. This indicates that turtles use the learned magnetic information to navigate back to their feeding grounds.

According to Ken Lohmann, a biology professor at the University of North Carolina, the ability to distinguish between magnetic fields of different geographical areas likely explains how many animals, including sea turtles, can travel long distances to specific locations.

But how exactly do turtles perceive this information? The study's authors note that the mechanisms have yet to be identified in animals; however, scientists have several hypotheses. For instance, one of these mechanisms, disrupted by magnetic fields in the radio frequency range (0.1–10 MHz), is thought to be "chemical magnetoreception."

Interestingly, the ability of loggerhead turtles to navigate using magnetic fields was disrupted by oscillating magnetic fields in the radio frequency range, while their ability to recognize fields associated with food was not affected. This suggests that the magnetic mapping sense and compass sense of turtles are based on two different mechanisms.