After decades of decline, bogong moths have returned in large numbers across southeastern Australia this spring, offering a hopeful sign for the species that had been pushed to near collapse by drought, habitat loss, and human activity.

The brown moths, measuring about 1.8 inches with distinctive black stripes and silver spots on their wings, undertake an annual migration from inland plains to the cooler alpine regions of eastern Australia. There, they enter a dormant state known as estivation between September and November, before returning inland in March and April to breed. Since the 1980s, the population has dramatically fallen, with particularly severe droughts in 2017 and 2018 reducing numbers by approximately 99.5 percent.

This year, however, has seen a resurgence. Citizen scientists using the Moth Tracker platform have recorded thousands of moth sightings since early September. According to Marissa Parrott, senior conservation biologist at Zoos Victoria and co-lead of the platform, the team has confirmed more than 1,600 moths from over 4,000 submissions, surpassing previous years’ counts. Parrott attributes the rebound to wetter, cooler conditions that have allowed the population to regain critical mass after years of environmental stress.

Locals across the region have shared footage of moths emerging from towels, swarming on windows, and even taking rides in car trunks. The moths had nearly vanished for many Australians, and their return has sparked celebrations and renewed interest in their ecological importance. The bogong moth serves as a key pollinator and is a vital food source for native species, including the mountain pygmy-possum, Australia’s only hibernating marsupial. The insects also hold deep cultural significance for Indigenous communities.

Despite the encouraging signs, experts caution that the species remains vulnerable. Eleanor Drinkwater, an entomologist at Western Sydney University involved with the citizen science initiative Bogong Watch, noted that climate change and ongoing habitat threats could alter the alpine refuges the moths depend on. Even modest temperature shifts have been shown to affect their behavior, underscoring the need for continued conservation efforts.

Both Parrott and Drinkwater emphasized the importance of protecting breeding grounds, restoring native plant corridors, and reducing artificial lighting along migration routes to support the moths’ recovery. While the resurgence this season offers hope, the species faces persistent challenges in adapting to a changing environment and human pressures.

For residents like Stephanie Helm, who first spotted the moths at her vineyard in New South Wales earlier this month, the insects’ return carries personal and symbolic meaning. After years of drought, wildfires, and storms, the sight of bogong moths feeding in her garden provides a reassuring sign that some aspects of the natural world are beginning to recover.

Scientists and citizen observers alike remain vigilant, marking this year’s moth migration as both a cause for celebration and a reminder of the ongoing work needed to protect a species integral to Australia’s ecosystems.