Full Breakdown
Sudden Surge of Bogong Moths in New South Wales Signals Possible Species Recovery
By Drooid · · How we work
Unexpected Swarms Across NSW
In the days leading up to September 28, 2026, residents of Sydney, the Hawkesbury, the South Coast and other parts of New South Wales reported large numbers of bogong moths entering homes, cars and gardens. Three households in the Blue Mountains each logged dozens of insects on a Monday, while a citizen-science sentinel near Mount Kosciuszko recorded more than 200 moths on a Sunday night. By the end of the weekend, iNaturalist’s Bogong Watch platform had received roughly 800 sightings, with over 200 logged in the preceding 24 hours.
Background: Historic Decline and Conservation Status
Bogong moths once migrated in swarms numbering up to 8 billion in the 1980s. Drought, fire and warming temperatures caused a catastrophic collapse of 99.5 percent between 2017 and 2019, prompting the IUCN to list the species as endangered in 2021. The moths are not protected under Australian federal or NSW legislation, despite their role as pollinators and as the primary summer food source for the critically endangered mountain pygmy-possum.
Citizen Science Data Highlights
- iNaturalist/Bogong Watch: ? 800 reports since the start of the week; > 200 in the last day.
- Zoos Victoria’s Moth Tracker: 2024 remains the previous record for monthly submissions; the current month has already surpassed that total.
- Volunteer counts: Sentinel volunteers using non-lethal lanterns have noted “high numbers” across NSW and the ACT, with Victoria lagging behind.
These data suggest a notable increase in adult moths during the current spring migration, which typically runs from mid-September to December.
Expert Interpretation and Official Responses
Dr Marissa Parrott, senior conservation biologist at Zoos Victoria, described the surge as “absolutely thrilling” and said the numbers may reflect a “stronger recovery.” She cautioned that climate-driven drought and warming continue to threaten breeding habitats.
Linnea Emneby, project manager for Bogong Watch, called the observations “incredibly encouraging” and noted that recent north-westerly winds likely aided the moths’ southward progress.
Hawkesbury Police Area Command issued a public reassurance that the insects are a natural part of the migration cycle and pose no threat to residents.
On-the-Ground Observations
Local volunteers reported moths gathering around outdoor lights, bottlebrushes and verandas. Some residents captured insects inside homes and were advised to gently release them outdoors. University of Sydney biologist Dieter Hochuli explained that the moths seek daytime shelter in crevices to avoid predation, and that strong winds can “hitch a ride” toward coastal areas.
Conflicting Estimates & Data Gaps
Historical accounts vary on peak migration size: one source cites up to 8 billion moths in the 1980s, another notes a decline to about 4 billion by 2017. Current estimates of the total number arriving in the Alps this season are qualitative (“large numbers”) rather than quantified, leaving a gap between citizen-science reports and precise population counts.
Verbatim Quotes
- “We’re absolutely thrilled with what we’re seeing,” — Dr Marissa Parrott
- “Before anyone reports a moth-related crime spree, please be reassured that these little travellers are a natural part of Australia’s migration cycle,” — Hawkesbury Police Area Command
What’s Next
Researchers will continue tagging and isotopic analysis of migrating moths to map their routes. Conservation groups recommend turning off unnecessary outdoor lighting, avoiding insecticide use, and promptly releasing any moths that enter homes. Ongoing monitoring through Bogong Watch and Moth Tracker will determine whether the surge represents a temporary anomaly or the start of a sustained population rebound.