Billions of Bogong moths return to Australia as El Niño threatens to spoil the comeback

Australia is witnessing a remarkable return of the Bogong moth, a species that once faced near-extinction. The migration of these moths, numbering in the billions, is an awe-inspiring natural spectacle that has not been observed since the species nearly vanished nearly a decade ago. The Bogong moth, once a springtime marvel across the nation's east coast, suffered a catastrophic collapse due to drought, pesticides, and habitat destruction starting in 2017, wiping out an estimated 99.5 percent of the population.

However, a glimmer of hope has emerged as scientists report a significant resurgence in the moth population. Conservation biologist Marissa Parrott expressed her delight at the return of the Bogong moths, calling it "one of nature’s great spectacles." In a typical year, four billion or more of these moths would leave the inland heat to seek refuge in the alpine caves of eastern Australia.

These massive clouds of moths would often block out the stars and moon as they passed overhead. Parrott, from Zoos Victoria, observed that the moths would densely cluster inside their caves, creating a stunning tiling pattern on the walls. These moths were known for their unique celestial navigation, using the Milky Way to guide them on their once-in-a-lifetime journey.

The Bogong moth plays a crucial role in Australian ecosystems, helping to spread pollen and serving as a vital food source for the critically endangered mountain pygmy possum.