Full Breakdown
Bogong Moth Swarms Return to Australian Skies
By Drooid · · How we work
Core Event: Massive Bogong Moth Swarms Reappear Across Eastern Australia
After a decade-long collapse that reduced the species by an estimated 99.5 %, swarms of the endangered Bogong moth have resurfaced in New South Wales, Victoria and the Australian Capital Territory during the current spring migration. Observers report clouds dense enough to obscure stars, a phenomenon not seen since the crash that began in 2017.
Background & Context
Historically, up to four billion Bogong moths migrated each spring from inland breeding grounds to the cool alpine caves of the Australian Alps, where they aestivate and provide the primary food source for the critically endangered mountain pygmy-possum.
From 2017-2019, severe inland droughts, increased insecticide use and habitat degradation caused a catastrophic decline. In December 2021 the IUCN listed the Bogong moth as endangered.
Research in 2025 showed the moths navigate using the Milky Way, the first invertebrates known to rely on celestial cues for long-distance travel.
Data & Statistics
- Historical peak: ? 4 billion moths per good year.
- Population crash: ? 99.5 % decline between 2017-2019.
- Current estimates: No precise figure; citizen-science platforms recorded more sightings in September 2026 than the entire year of 2024 (Streamlinefeed, Guardian).
Official Statements & Responses
Conservation biologist Marissa Parrott of Zoos Victoria described the resurgence as “hope-giving” and linked it to “wetter, cooler conditions” after the drought years. Researchers also noted strong winds diverting moths toward urban areas, increasing public encounters.
On-the-Ground Reports
Residents across Sydney, Canberra and regional towns reported startled reactions as moths emerged from drying towels, gathered on walls, and swarmed around porch lights. Videos show dense clouds that briefly dimmed streetlights. Local authorities have urged the public not to use insecticides and to assist moths in continuing their migration.
Conflicting Reports & Gaps
While historical figures cite up to four billion moths in a strong year, no source provides a current quantitative estimate of the rebound. Citizen-science data indicate a marked increase, but the exact scale remains uncertain.
Verbatim Quotes
- “So many Bogong moths would come through that they could block out the stars and the moon as they went overhead,” — Marissa Parrott
- “They are very, very important to Australian ecosystems,” — Eleanor Drinkwater, university insect researcher
- “Turn off unnecessary outdoor lights, then they won’t be as drawn to buildings, to homes, to businesses,” — Marissa Parrott
What’s Next
Scientists caution that an upcoming El Niño forecast could raise summer temperatures, potentially threatening the fledgling recovery. Ongoing monitoring through Moth Tracker and the citizen-science project Bogong Watch will track population trends. Public guidance includes turning off unnecessary outdoor lighting and gently guiding any insects found indoors back outside.