Australia's native bees are among the hidden casualties of the devastating Black Summer bushfires, according to a new study.

A team of scientists from universities across Australia assessed the impact of the fires on 553 native bee species.

They found at least 11 species of bees met International Union for Conservation of Nature (IUCN) criteria to be listed as threatened, they report today in the journal Global Change Biodiversity.

The 2019–20 bushfires decimated about 24 million hectares of land, and killed or displaced an estimated 3 billion animals.

"When we hear about wildfires in Australia there's been a lot of attention on vertebrates ... like kangaroos and koalas," said study co-author Stefan Caddy-Retalic, an ecologist at the University of Adelaide and University of Sydney.

Dr Caddy-Retalic said the findings showed more needed to be done to conserve Australia's bees in the face of threats such as frequent fires and climate change.

"It would be fantastic to see governments at all levels across Australia step up in collecting data that allows us to better understand threats.

"We need to build that fence at the top of the cliff rather than trying to rescue species once they've fallen off."

Lots of bees ...

Australia has around 1,650 species of native bees that we know of.

While some bees build their nests in stems of grass, others live underground.

Three species are currently recognised by the federal government as critically endangered.

There has been some research into the impact of bushfires on a handful of other species such as the spectacular green carpenter bee (Xylocarpa aerata).

But not much is known about Australia's other native bee species.

To find out, a team led by bee expert James Dorey of Flinders University pored over publicly available data about all known species from the Atlas of Living Australia and museums.

They then cross-referenced the information about the bees with a range of government data about habitats, history of fires and fire intensity.

The team then narrowed the list down to species living in high fire intensity regions and that had traits that made them more vulnerable.

They found at least nine species met the criteria for the IUCN Red List category for vulnerable and two met for the category of endangered.

The most endangered species on this list lost between 55 and 59 per cent of their habitat in the fires.

But the list put forward to the IUCN does not include the green carpenter bee.

This bee is listed by state governments as endangered in South Australia, where an estimated 95 per cent of its last remaining habitat on Kangaroo Island was lost during the fires, and extinct in Victoria.

The analysis suggested it was less affected in New South Wales, but the researchers said more specific studies of local populations were needed.

Dr Caddy-Retalic said the study showed the power of using publicly available data to assess the threat to different species.

"Sometimes scientists feel like we're paralysed by not having the data we need to be able to answer some of the big questions.

"But this shows in many cases we do have enough data to provide some assessment."

But so little information

Tobias Smith, a native bee expert at the University of Queensland not involved in the research, said the study was an amazing use of existing data, but the findings were "unfortunately unsurprising".

Fire is only one threat that bees face, along with climate change, invasive species and destruction of habitat.

"We know very little about Australian bees, but we know about the processes that can potentially affect them, and this confirms some of the things that we thought were going on," Dr Smith said.

He said trends seen in the study were probably even much more widespread.

"When they assessed all the known bee species in Australia ... only 30 per cent of those had enough data for them to do their analysis," Dr Smith said.

"So what's going on with those bees?"

And this is just the number of species we know about, he added. There are possibly up to 2,500 species in Australia.

"There's potentially another 30 per cent of bees we haven't discovered and given names to.

"If we know this little about these charismatic bees, imagine all those other insect groups that don't get as much attention as bees do."

A decision about the listing of the bees by the IUCN is expected by the end of the year.