Bogong Moths Surge Toward the Alps: What 800 Sightings Mean
About 800 Bogong moth sightings were logged across New South Wales in late September 2026 as Agrotis infusa moved in large numbers toward the Australian Alps.
ABC News reported hundreds of sightings across the state on September 28, 2026, during the annual pilgrimage to the Snowy Mountains. ABC News In the week before September 28, swarms filled the skies over the Goulburn-Murray and Shepparton region as they travelled from lower altitudes toward the Snowy Mountains. In 2026, moths also entered homes in New South Wales, the Australian Capital Territory and Victoria. SBS
Spring, from September to November, starts the annual migration. Numbers rose quickly. Each spring, billions of moths fly up to 1,000 km to escape heat in south-east Australia. The flight is highly directed. They navigate to and from the Australian Alps using magnetic cues from Earth's magnetic field.
The destination is specific: cool caves in the Australian Alps, where they spend summer in aestivation, a summer version of hibernation. The migration cycles between breeding grounds and caves.
ABC News described Bogong moths as endangered in its September 28 report. Populations have declined since the 1980s, according to a September 29 briefing. The moths support alpine ecosystems. Scientists said the 2026 presence in homes across NSW, ACT and Victoria is great news for the species. The Guardian reported huge swarms surprised NSW residents and that the event may point to species recovery. The Guardian
Such numbers have been seen before. A swarm of millions, mistaken for an approaching rain cloud, caused panic during the Sydney Olympics closing ceremony.
The broader context here is what one strong season can and cannot tell us. For a long-distance moth that sleeps through summer and feeds alpine food webs, numbers vary a lot year to year. A widely seen movement after years of decline will interest monitoring programs and alpine managers. Whether 2026 was an exception or a turning point will depend on what happens across breeding, migration and aestivation. In my view, the questions now are continuity and distribution: whether moths fill caves and return after summer, and whether sightings reach beyond houses into alpine shelters.
