Bogong moth sightings in NSW and ACT suggest potential species recovery
- Swarms of bogong moths have arrived across New South Wales and the Australian Capital Territory, surprising residents and offering citizen science networks a signal of potential recovery for...
- Project manager Linnea Emneby stated that bogong sentinels—volunteers equipped with non-lethal bug lanterns stationed in all directions from Mount Kosciuszko—reported high numbers of the insects during the migration.
- The recent influx follows a catastrophic population collapse between 2017 and 2019, when an estimated 4 billion migrating moths dropped by up to 99.5 percent.
Swarms of bogong moths have arrived across New South Wales and the Australian Capital Territory, surprising residents and offering citizen science networks a signal of potential recovery for the endangered native insect. Hundreds of sightings of the nocturnal moths were logged over the weekend on the iNaturalist platform for Bogong Watch, an initiative run by Invertebrates Australia, following an annual migration push of up to 1,000 kilometers toward cool alpine caves.
Citizen Science Networks Track Migration Waves Across Southeast Australia
Project manager Linnea Emneby stated that bogong sentinels—volunteers equipped with non-lethal bug lanterns stationed in all directions from Mount Kosciuszko—reported high numbers of the insects during the migration. Three New South Wales households each logged dozens of moths on Monday, while one sentinel sighted more than 200 bogongs on Sunday night.
Dr. Marissa Parrott, a reproductive biologist at Zoos Victoria, noted that the Moth Tracker program had recorded a dramatic increase in public submissions. The reports just keep coming in … one of my team members was in tears with excitement this morning,
Parrott said. She added that September sightings had already surpassed the total number recorded across the entire previous year, driven by favorable wetter and cooler weather conditions across south-eastern Australian migratory zones in Canberra, Sydney, Newcastle, and Melbourne.
Historical Population Collapse and Ecological Importance
The recent influx follows a catastrophic population collapse between 2017 and 2019, when an estimated 4 billion migrating moths dropped by up to 99.5 percent. Historically, the insects arrived in the Australian Alps by the billions each summer to escape warmer weather, occasionally swarming Parliament House in Canberra or causing weather forecasters to mistake stadium-drawn swarms for rain clouds during the 2000 Sydney Olympic Games closing ceremony. Weighing a third of a gram and measuring roughly the size of a 50-cent piece, the moths play a critical ecological role as plant pollinators and serve as a vital food source for the critically endangered mountain pygmy possum. The International Union for the Conservation of Nature listed the bogong moth as endangered in 2021, though the species lacks formal threatened status under federal conservation laws.
Conservation Guidance for Public Encounters
Experts urge residents encountering the migrating insects to turn off unnecessary outdoor lighting, avoid using insecticides, and upload photographic evidence to the Moth Tracker or Bogong Watch portals. Because female bogongs can carry up to 2,000 eggs, researchers emphasize that every individual is valuable to the ongoing recovery effort.
If any come into the house, gently place them back outside,
Parrott advised. They don’t do any damage, they don’t eat clothes. They pollinate the plants as they go through, so that’s a big help for people who love their gardens.
While current numbers are encouraging, researchers remain cautious about long-term climate pressures, noting that future El Niño cycles and drier conditions could threaten subsequent migration seasons.