Years of intense drought severely depleted the Bogong moth's billion-strong population, with numbers dropping to their lowest levels in 50 years.
But the latest migration snapshot, released by the Australian Conservation Foundation on Saturday, shows wetter conditions have helped the endangered species bounce back.
"This migration season is looking really encouraging," CSIRO research scientist Peter Caley said.
"We've seen good moth numbers arrive in the Australian alps and we're hoping that's going to continue because the last few years have been really ordinary."
Each spring, the small moths migrate thousands of kilometres to reach the mountains of eastern Australia.
About 4.5 billion once made the journey but numbers have dwindled, dropping by about 99.5 per cent because of the severe drought conditions seen between 2017 to 2019.
Scientists have been monitoring the migrating moth populations at Mount Gingera in the ACT, Mount Selwyn and Kiandra in NSW, and Mount Hotham in Victoria.
Numbers fluctuate but the overall conclusion is that the Bogong population is returning to pre-2017 levels.
"This is really good news for a species that had collapsed," the conservation foundation's Darcie Carruthers said.
"But it's really important to remember that the threats to this species still remain, and top of the list are the impacts of climate change."
Drought has already proven to be disastrous for the moth species, which was listed as an endangered species last year.
Habitat destruction, unsustainable agricultural practices and invasive species also pose a threat.
It is important to protect the Bogong moth because it plays an important role in Australia's alpine ecosystem, Mr Caley said.
"They provide food for the mountains' pygmy possums, who are restricted to boulder fields in a handful of locations in the High Country," he said.
"But they also provide food to animals during their migration and they shift an enormous amount of nutrients from the lowlands to the highlands.
"That cascades down through the whole ecosystem."
The Australian Conservation Foundation is calling on the federal government to improve environment laws and boost investment to protect the endangered species.
"We are at a pivotal moment for the Bogong moth," Ms Carruthers said.
"The 2022 rebound should be seen as motivation to urgently act on climate change so we can ensure the species continues to thrive."
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