Last month's heatwave in northern Queensland is believed to have killed more than 23,000 spectacled flying foxes, which is about one-third of the nation's entire population.

"Losing a third of the species on a hot afternoon I would argue certainly strengthens the case for both the Federal and Queensland Governments to consider lifting the species from 'vulnerable' to 'endangered', if not 'critically endangered'," said Dr. Justin Welbergen, ecologist with the Hawkesbury Institute for the Environment at Western Sydney University.

Dr. Welbergen estimates there were about 75,000 spectacled flying foxes in Australia.  But the colonies were around Cairns where the temperature got above 42 C Degrees for two consecutive days, and the was entirely two much for the species that's endemic in the area.

"What's scary about this one is the spectacled flying fox has been hit," said Tim Pearson, a consultant wildlife ecologist specializing in flying foxes.  "As far as we know, they've never suffered heat deaths before."

With no plan in place to clean up after such a disaster, it was up to wildlife volunteers to locate and remove carcasses and rescue orphaned young ones.  And it is more than likely Australia will see this sort of things repeated, and not just with flying foxes.

"Extreme heat events are increasing in frequency, also in terms of intensity and duration, and we can expect more extreme temperatures to occur increasingly frequently further north," said Dr. Welbergen.  "A certain proportion of such an extreme event can certainly be statistically attributed to climate change for sure.  I think the jury is no longer out on that."

The environment minister Melissa Price is now considering the threatened species scientific committee's (TSSC) advice to upgrade the spectacled flying fox's threatened status from "vulnerable" to "endangered".

"Government inaction for our threatened flying foxes is beyond a joke, with the recovery plan that could have helped stop these mass deaths overdue by more than 12 years and nowhere in sight," said Evan Quartermain of the Humane Society International (HSI).  "The time to act was a decade ago, and we can't wait a moment longer.  This is an unprecedented and shocking heat-stress event, with climate change seeing threatened species never before affected dropping by the thousands and dependent pups left motherless."