Bogong moths use constellations and the Milky Way to navigate and travel at night.

MAC Editorial, June 18 (EFE).- Every spring, millions of Bogong moths undertake a thousand-kilometer journey across Australia, from the plains of Queensland and New South Wales to the Australian Alps, where they spend the summer in hibernation. Upon awakening, they return to the warmer eastern lands to mate and die.

Although it was known that these invertebrates—like birds—use the Earth's magnetic field to make this epic nocturnal journey, how they navigated remained one of nature's great mysteries. Until now.

A study published Wednesday in the journal Nature has found that Bogong moths ( Agrotis infusa ) use star constellations and the Milky Way to navigate, a type of navigation previously observed only in humans, some birds, and possibly seals.

Celestial navigation and magnetic field

The study reveals that these moths combine celestial navigation with the Earth's magnetic field to locate a specific destination they have never seen before: the cool caves of the Snowy Mountains, where they will spend the summer.

Led by scientists from Lund University (Sweden), the Australian National University (ANU) and the University of South Australia (UniSA), the research has solved one of nature's great migratory mysteries, which involves around four million moths each year.

"We knew that some birds and even humans could use stars to navigate long distances, but this is the first time it's been demonstrated in an insect," notes Eric Warrant of Lund University and a researcher at ANU.

"These moths are incredibly precise. They use the stars as a compass to navigate vast distances, adjusting their course based on the season and time of night," the researcher comments.

A journey of a thousand kilometers

To conduct the study, the authors captured chicks at the beginning of their spring or autumn migrations and placed them in a flight simulator that recreated natural night skies and had the Earth's magnetic field blocked. The goal was to see how they navigated in different sky conditions.

When presented with a natural starry sky, the moths consistently flew in the correct migratory direction for the season: south in spring and north in autumn. And when the starry sky was rotated 180 degrees, the moths continued to navigate correctly.

But when the stars became mixed, their orientation disappeared.

However, the exact features of the night sky that aid moth migration are still unclear, and it remains unknown whether moths can see individual stars with their compound eyes.

The authors believe the Milky Way is a bright band of light in the southern half of the sky that is most likely visible to Bogong moths.

Neurological basis

The team also investigated the neurological basis of this behavior, identifying specialized neurons in the moth's brain that respond to the orientation of the starry sky. These cells, which are located in brain regions responsible for navigation and orientation, fire most strongly when the moth faces south.

"This type of directional tuning demonstrates that the Bogong moth's brain encodes celestial information in a surprisingly sophisticated way. It's a remarkable example of the complex navigational capabilities embedded in an insect's tiny brain," Warrant emphasizes.

The authors are convinced that the discovery could serve as a basis for technologies in robotics, drone navigation, and even conservation strategies for species threatened by habitat loss or climate change. However, this requires protecting the migratory routes of these moths, which have declined dramatically in recent years and have entered the list of vulnerable species. EFE

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Image: A Bogong moth. Photograph provided by Dr. Ajay Narendra (Macquarie University, Australia). EFE