A Tiny Navigator, a Monumental Journey
In a groundbreaking discovery, researchers have revealed that the Bogong moth (Agrotis infusa), an iconic Australian insect, uses stars and even the Milky Way for its epic annual migration. This makes it the first known invertebrate to employ a stellar compass for long-distance navigation, a feat previously attributed mainly to birds, seals, and humans.
Each spring, billions of these unassuming moths emerge from their breeding grounds in southeast Australia and embark on a journey of up to 1,000 kilometers (620 miles) to the cool alpine caves of the Snowy Mountains. There, they aestivate (a form of dormancy similar to hibernation) through the summer before they make the return journey in autumn to breed and die. How these tiny creatures, with brains smaller than a grain of rice, manage to pinpoint a destination they’ve never visited before has long been a scientific mystery.
Image by Pixabay
Unveiling the Celestial Compass
Previous research had already established that Bogong moths use Earth’s magnetic field as a compass. However, recent studies, published in the journal Nature, have now confirmed that they also rely on celestial cues. Scientists from institutions including Lund University in Sweden, the University of South Australia, and the Australian National University conducted experiments using sophisticated flight simulators in magnetically neutral environments.
When researchers presented a natural starry sky, the moths consistently oriented themselves in the correct migratory direction – southward in spring and northward in autumn. When the researchers rotated the projected starry sky 180 degrees, the moths changed their flight direction accordingly. Crucially, when researchers scrambled the star patterns, the moths lost their orientation. This indicates that they aren’t simply flying towards the brightest light, but are actively “reading” patterns in the night sky.
Implications for Science and Conservation
This remarkable discovery highlights the incredible navigational capabilities we find in the natural world and could have implications for fields ranging from robotics and drone navigation to conservation efforts for this vulnerable species.
