# Bogong Moth Population Rebounds Across Eastern Australia After Severe Decline

> Vast numbers of Bogong moths have returned to eastern Australia in late 2026, marking a significant rebound for the endangered species following a 99.5% population crash.

By PrimaryBrief newsroom · Published 2026-10-25T21:12:29.041406Z
Canonical: https://primarybrief.com/article/bogong-moth-population-rebounds-across-eastern-australia-after-severe-decline-713b61a5

Huge numbers of Bogong moths have appeared across eastern Australia in late September and October 2026, with sightings in New South Wales alone surpassing all of the previous year's total [1][2]. This revival follows a severe population crash between 2017 and 2019, which reduced their numbers by up to 99.5% [2][14][17][20].

The return of these moths influences Australian ecosystems, as they provide food for species like the Mountain Pygmy-possum, contribute to pollination, and hold deep cultural significance for Australia's First Nations peoples [2][5][14][16][17][18][20]. Their dramatic return offers optimism for the health of the broader food web [2][18].

## What the records show
Citizen science initiatives, including Bogong Watch and Zoos Victoria's Moth Tracker app, have documented the extensive recovery [1][9][18]. Dr. Marissa Parrott, a Senior Conservation Biologist at Zoos Victoria, reported 12,000 verified sightings by October 2026, stating the current population is “six times higher than our previous best seasons” [3]. The moths are appearing across New South Wales, the Australian Capital Territory, and Victoria, with swarms observed in backyards and homes along Australia's east coast [1][2][3][4][5][19]. Ecologist Ken Green noted that these “explosion of bogongs across the skies of eastern Australia” is positive news for plants and dependent endangered species [4]. Citizen science programs have recorded more Bogong moth sightings in September 2026 alone than in all of last year combined [2].

## Timeline
The Bogong moth population experienced a gradual decline from the 1980s, primarily due to factors like pesticide use and urban light pollution [4][6][14][17]. This decline became a catastrophic crash between 2017 and 2019, with numbers plummeting by up to 99.5% [2][4][6][14][17][20]. The severe drought in inland breeding grounds during these years was a major contributing factor [4][11][14][17][20]. In December 2021, the International Union for the Conservation of Nature (IUCN) added the Bogong moth to its Red List as an endangered species [2][16][20]. The widespread return of the moths began in late September and October 2026 [1][2][4][5].

## What changed and for whom
Scientists attribute the rapid rebound primarily to cooler, wetter conditions and increased rainfall, specifically three consecutive years of La Niña weather patterns [2][17][19][20]. These conditions likely created ideal breeding and feeding environments for the moth larvae [5][19]. The recovery significantly benefits the critically endangered Mountain Pygmy-possum, which relies on Bogong moths as a key food source after hibernation [2][11][12][13][14][15][17][18][20]. The moths also provide essential pollination services to native plants and support a broader food web [2][5][14][17][18]. Historically, Bogong moths were a food source for Aboriginal peoples, who traveled to alpine regions to harvest them and feast with other tribes [16][17][20].

## What officials are saying
Steve Whan, representing the alpine area of Monaro in the New South Wales parliament, stated, “It's really exciting to see this recovering population coming our way” [5]. Whan emphasized the moths' positive impact on the ecosystem, including supporting native wildlife like the pygmy-possum and pollinating eucalyptus trees [5]. James Todd, Victoria's Chief Biodiversity Officer, also welcomed the return, saying, “The jump in numbers is a positive sign for biodiversity” [5].

## What we could not confirm
The exact figures from ecologist-led surveys for 2026, to compare with citizen science data, are not yet available [4]. The long-term sustainability of the current population rebound under changing climate conditions, especially with the looming prospect of El Niño, remains an open question [18][20].

## Evidence cited
1. facebook.com — https://facebook.com/
2. Impactful Ninja (Impactful Ninja) — https://impactful.ninja/
3. Ground News (Ground News) — https://ground.news/
4. theguardian.com (The Guardian) — https://theguardian.com/
5. Swarms of moths in Australia lift hopes of recovery for endangered species - The Jakarta Post (The Jakarta Post) — https://www.thejakartapost.com/culture/2026/10/03/swarms-of-moths-in-australia-lift-hopes-of-recovery-for-endangered-species.html
6. Bogong Moth Swarms Return to Southeast Australia - Human Progress (Human Progress) — https://humanprogress.org/bogong-moth-swarms-return-to-southeast-australia/
7. Bogong Watch - Citizen Science (Citizen Science) — https://citizenscience.org.au/2026/03/10/bogong-watch/
8. Bogong Watch (bogong.org) — https://bogong.org/
9. Citizen Science – Bogong Watch – Mid Lachlan Landcare (Mid Lachlan Landcare) — https://midlachlanlandcare.org/2026/09/21/citizen-science-bogong-watch/
10. Bogong Watch (Invertebrates Australia) — https://invertebratesaustralia.org/projects/bogong-watch
11. Decline in bogong moth numbers leaves mountain pygmy possums starving | The forgotten climate change crises | The Guardian (The Guardian) — https://www.theguardian.com/australia-news/2019/feb/24/decline-in-bogong-moth-numbers-leaves-mountain-pygmy-possums-starving
12. Mountain Pygmy Possum and Bogong Moth Dietary Analysis – Research Centre for Applied Alpine Ecology (rcaae.org) — https://rcaae.org/current_projects/mountain-pygmy-possum-and-bogong-moth-dietary-analysis/
13. Mountain Pygmy-possum and the Bogong moth - Cesar Australia (cesaraustralia.com) — https://cesaraustralia.com/sustainable-agriculture/mountain-pygmy-possum-and-the-bogong-moth/
14. The Bogong Moth and the Mountain Pygmy-possum: a story of interconnectedness - The Royal Society of Victoria (The Royal Society of Victoria) — https://rsv.org.au/the-bogong-moth-and-the-mountain-pygmy-possum-a-story-of-interconnectedness/
15. The Australian Pygmy-Possum Is Starving Because Its Favorite Snack Keeps Getting Lost - Atlas Obscura (Atlas Obscura) — https://www.atlasobscura.com/articles/mountain-pygmy-possum-bogong-moth
16. Agrotis infusa - Wikipedia (Wikipedia) — https://en.wikipedia.org/wiki/Agrotis_infusa
17. The Wilderness Society - Yay – bogongs (no, not bogans) are BACK... (facebook.com) — https://www.facebook.com/wilderness.org.au/posts/10158229712537243/
18. Bogong Moths Staging Dramatic Comeback Across Southeast Australia: Hopeful Sign of Recovery for Endangered Species - Bedrock News (Bedrock News) — https://bedrocknews.com/news/bogong-moths-recovery-2026
19. Bogong Moths Make Dramatic Comeback In Australia After Near Collapse - Impactful Ninja (Impactful Ninja) — https://impactful.ninja/bogong-moths-comeback-australia-2026/
20. Bogong moth recovery report | ACF (Australian Conservation Foundation) — https://www.acf.org.au/bogong-moth-recovery-report
21. Spring's Winged Thing Continues: Bogong Weather Anomaly + Butterflies (pittwateronlinenews.com) — https://www.pittwateronlinenews.com/Archives/2026/10%20-%20Issue%20473/Spring'sWingedThingContinuesBogongWeatherAnomaly+Butterflies.php
22. ‘Thrilled’: huge swarms of bogong moths surprise NSW residents and may point to species’ recovery | Bogong moths | The Guardian (The Guardian) — https://www.theguardian.com/environment/2026/sep/29/thrilled-huge-swarms-of-bogong-moths-surprise-nsw-residents-and-may-point-to-species-recovery
23. The great moth revival - Earth to Sea News (Earth to Sea News) — https://earthtoseanews.com/2026/10/17/the-great-moth-revival/
24. Bogong moths are back in numbers – Australian Environmental Education (Australian Environmental Education) — https://www.australianenvironmentaleducation.com.au/news/bogong-moths-are-back-in-numbers/
25. From spectacular return to secure recovery (rodbenson.com) — https://rodbenson.com/from-spectacular-return-to-secure-recovery/
26. Swarms of moths in Australia lift hopes of recovery for endangered species (Radio USA) — https://radiousa.com/news/swarms-of-moths-in-australia-lift-hopes-of-recovery-for-endangered-species
27. ‘Thrilled’: huge swarms of bogong moths surprise NSW residents and may point to species’ recovery | Bogong moths | The Guardian (The Guardian) — https://www.theguardian.com/environment/2026/sep/28/thrilled-huge-swarms-of-bogong-moths-surprise-nsw-residents-and-may-point-to-species-recovery
28. Endangered bogong moths swarm New South Wales, raising hopes of recovery (Digg) — https://digg.com/digg/bogong-moths-nsw-recovery
29. The bogong moth is more than an insect: It’s a cultural and ecological keystone (Mongabay Environmental News) — https://news.mongabay.com/2026/08/the-bogong-moth-is-more-than-an-insect-its-a-cultural-and-ecological-keystone/
30. The Bogong moth, Agrotis infusa: cultural context, knowledge gaps, conservation and monitoring options (National Environmental Science Program) — https://www.nespthreatenedspecies.edu.au/publications-and-products/the-bogong-moth-agrotis-infusa-cultural-context-knowledge-gaps-conservation-and-monitoring-options
31. Bringing back the Bogong Moth - The P.S. (Parliamentary Souvenir) (Parliamentary Souvenir) — https://ps.org.au/blog/bringing-back-the-bogong-moth
32. Bogong Moth - Alpine Resorts Victoria (Alpine Resorts Victoria) — https://www.alpineresorts.vic.gov.au/environment/flora-and-fauna/bogong-moth
33. A cultural and ecological keystone in danger – Rendere (rendere.org.au) — https://rendere.org.au/2025/05/16/cultural-ecological-keystone-in-danger/
34. The Bogong Moth's Big Journey – Up2Us Landcare Alliance (Up2Us Landcare Alliance) — https://www.up2us.org.au/the-bogong-moths-big-journey/
35. Bogong Moth (Australian Museum) — https://australian.museum/learn/animals/insects/bogong-moth/
36. Moths, not rain, to blame for false weather forecasts in NSW (7NEWS.com.au) — https://7news.com.au/news/weather/moths-not-rain-to-blame-for-false-weather-forecasts-in-nsw-c-12193581
37. Bogong moths are back in big numbers – and they’re causing rain radar confusion | Bogong moths | The Guardian (The Guardian) — https://www.theguardian.com/australia-news/2026/oct/16/bogong-moths-are-back-in-big-numbers-and-theyre-causing-rain-radar-confusion
38. Bogong moth numbers soar across eastern Australia after La Niña wet weather - ABC News (ABC News) — https://www.abc.net.au/news/2026-10-01/bogong-moth-numbers-rise-after-la-nina-wet-weather/103234568
39. Bogong moths make a comeback after years of decline, thanks to La Nina - SBS News (SBS News) — https://www.sbs.com.au/news/article/bogong-moths-make-a-comeback-after-years-of-decline-thanks-to-la-nina/3w6t8o4
40. The great moth revival: Bogongs return in record numbers - The Age (The Age) — https://www.theage.com.au/environment/conservation/the-great-moth-revival-bogongs-return-in-record-numbers-20260930-p5j4v2.html
41. Long-distance migration of the bogong moth (Agrotis infusa) and its role in alpine ecosystem energetics - Nature Ecology & Evolution (Nature Publishing Group) — https://www.nature.com/articles/s41559-020-01382-y