Peter Caley

New discoveries about how bogong moths navigate long distances could help advance technologies in robotics, navigation systems, and conservation planning. Every year, billions of bogong moths travel up to 1,000 km from across southeastern Australia to summer in cool caves in the Australian Alps before returning to their breeding grounds in autumn to reproduce and die. In a landmark study published today in Nature, Academy Corresponding Member Professor Eric Warrant FAA and his international research team reveal how these moths use a stellar compass, combined with cues from Earth's magnetic field, to navigate hundreds of kilometres to a destination they've never previously visited. While many species use predictable celestial cues like the Milky Way to orientate themselves over short distances, the ability to navigate long distances using stars is much less common. While humans and some birds have been known to use stars for long-distance navigation, this is the first time an invertebrate has been shown to have this ability. Bogong moths use the stars to guide them over vast distances—adjusting their relative bearing based on the season and time of night. Using specialised flight simulators that isolated moths from Earth's magnetic field, Professor Warrant's team took neural readings and tested how moths oriented themselves under different projected skies. Under naturally oriented starry skies, moths consistently travelled in seasonally appropriate migratory directions and reversed accordingly when the projection was rotated 180 degrees. When stars were randomly arranged, moths became disoriented, showing they read specific patterns in the night sky to determine geographical direction rather than following simple visual cues. The team identified neurons that responded consistently to the moth's orientation in relation to the starry sky. This directional tuning shows the sophisticated way celestial information is encoded in the tiny bogong moth brain. Previous research into invertebrate visual and navigational systems has informed developments such as novel camera systems and low-light sensors for robotics. A better understanding of bogong moths' navigational system could inspire further technological developments and help inform conservation strategies across their migration routes. Learn more about Professor Warrant’s research in our video: