“How a Tiny Brown Moth Uses the Stars to Navigate 600 Miles, Just Like Humans and Birds” – CNN

(CNN) — In Australia, a small species called the Bogong moth embarks on an incredible migration journey. Each spring, they travel about 620 miles (1,000 kilometers) at night from southeastern Australia to chill in caves in the Australian Alps, escaping the heat. Come fall, they return to mate and die. A recent study reveals just how these tiny moths navigate this long trek.

Researchers discovered that Bogong moths rely on the stars for navigation, almost like a compass. “It is an act of true navigation,” says Eric Warrant, a scientist from Lund University in Sweden and coauthor of the study published in the journal Nature. He points out that this ability is a first for invertebrates.

But the stars aren’t their only guide. These moths can also sense the Earth’s magnetic field. Using both navigational tools gives them a backup in case they encounter obstacles, like cloudy skies or magnetic anomalies.

Remarkably, these tiny creatures have a small brain and nervous system yet manage to navigate with great skill. “It adds to the growing consensus that insects are quite remarkable,” Warrant notes.

The Bogong moth, or Agrotis infusa, is nocturnal and has wings about 2 inches (5 centimeters) wide. Though they might seem ordinary, they play a critical role in their ecosystem and have been crucial to Indigenous Australian cultures for millennia.

Sadly, the moth population is declining, and they’ve been classified as endangered. Factors like climate change, habitat loss, and perhaps even light pollution are impacting their numbers. According to the International Union for Conservation of Nature’s Red List, these moths are now in danger.

Warrant’s curiosity about the moths led him to set up experiments simulating their conditions in a lab. With a small rod attached to the moths, he observed their flight patterns. When the sky was projected above, the moths instinctively flew in their migratory direction, demonstrating their impressive navigation skills.

Interestingly, the moths’ eyes are adapted to see the night sky much better than humans can. They can perceive the dim light of stars about 15 times more brightly, allowing them to effectively use starlight as a guide.

While only a few creatures can navigate like the Bogong moth, such as the monarch butterfly and certain dung beetles, these insects do so in different ways. The moths are unique since they can navigate long distances based solely on their internal compass, which is instinctual since they make this journey only once in their lifetime.

“Imagine this—when the moths emerge from the soil, they’ve never seen the caves or flown this route before, yet they just know where to go,” Warrant marvels.

The find is not just interesting; it opens doors for further research. According to Jason Chapman from the University of Exeter, many questions remain about how the moths process and use the information from their environment. Understanding this could shed light on navigation mechanisms used by other migratory insects.

Jane Hill, a professor of ecology at the University of York, emphasizes that these findings deepen our understanding of how insects migrate across vast distances. It’s particularly fascinating considering that different generations undertake this journey each year, showing how powerful innate navigational skills can be.

In a world where insect populations are struggling, the Bogong moth’s journey is a reminder of nature’s wonders and the delicate balance of ecosystems.



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