An international research team led by Dr. Pauline Fleischmann from the University of Oldenburg (Germany) has discovered that the desert ant species Cataglyphis nodus can navigate based on the Earth’s magnetic field.
This report has been published in the journal Current Biology.
Interestingly, they utilize the polarity of the magnetic field (the North-South axis) instead of “inclination,” which is common among many other insect species.
This finding not only sheds light on the unique navigation abilities of desert ants but also opens up possibilities regarding their unique magnetic field perception mechanisms, which differ from many other animal species.
The Remarkable Navigation Abilities of Desert Ants
Desert ants can sense the North-South direction of the magnetic field to navigate back to their nests. (Photo: Eurasia Review).
Desert ants live in harsh environments such as salt flats in the Sahara Desert or pine forests in Greece. Even without clear landmarks, they can travel hundreds of meters to forage for food and return to their nests in a straight line.
Dr. Fleischmann and her colleagues conducted a series of experiments with ants from Greece. They were placed in a Helmholtz coil system to create an artificial magnetic field with varying directions and components. The goal was to test the ants’ responses to changes in the magnetic field components.
When the researchers altered the inclination of the magnetic field, meaning the angle between the magnetic field lines and the Earth’s surface, the ants did not change their navigation behavior. However, when the North-South axis of the magnetic field was reversed, the ants completely misjudged their direction, believing the entrance to their nest was in a different location.
Based on these results, the research team concluded that desert ants do not rely on the inclination of the magnetic field like birds or butterflies. Instead, they use the polarity of the magnetic field for short-distance navigation, a mechanism akin to a “mini compass.”
Distinct Magnetic Field Perception Mechanisms
Currently, there are two main hypotheses regarding how animals perceive the magnetic field:
- Radical Pair Mechanism: A light-dependent quantum effect, commonly observed in songbirds and butterflies.
- Magnetic Particles: Small magnetic particles in nerve cells function like a compass needle, prevalent in species such as sea turtles, bats, and pigeons.
The research team suspects that the desert ants’ ability to perceive the magnetic field is related to magnetic particles like magnetite (an iron mineral), rather than the radical pair mechanism.
Significance of the Discovery
This finding not only expands our understanding of how animals navigate but also lays the groundwork for researching the evolution of magnetic sense in the natural world. Dr. Fleischmann stated: “This type of compass based on magnetic polarity is particularly useful for navigation over short distances, which is crucial given the harsh habitats of desert ants.”
This study also opens new avenues for understanding the navigation mechanisms of other species such as bees and wasps.
The discovery that desert ants use an entirely different mechanism to perceive the magnetic field compared to species like butterflies or cockroaches highlights the incredible diversity within the animal kingdom.
Similar studies in the future may help humans gain deeper insights into how various animal species adapt to harsh environments, while also providing ideas for advanced positioning technology.
