It was a daring mission to rescue some of Australia's rarest birds from the ferocious East Gippsland bushfires.

Key points: Fifteen bristlebirds have been rescued from far-eastern Victoria as an insurance population against bushfires

Fifteen bristlebirds have been rescued from far-eastern Victoria as an insurance population against bushfires Three of the birds died after a few days at Melbourne Zoo

Three of the birds died after a few days at Melbourne Zoo The East Gippsland fires are still active, and the birds will not be returned until it is completely safe for them

Nothing quite like this had been done before.

The rescue team needed to get in, take a few bristlebirds for safe keeping, and get out.

There are only three populations of bristlebirds left in Australia: one on the Queensland border, one in New South Wales and a third, tucked away in a tiny, far-east corner of Victoria.

When a huge fire threatened the town of Mallacoota on New Year's Eve, biologist Rohan Clarke watched the news in fear.

"That little corner of Victoria is really important in terms of biodiversity," Dr Clarke said.

"It's got really rich species numbers, and because it's jammed right in that corner, it gets a little of the humid weather from NSW, so it's got species that don't occur anywhere else in the state."

In early February, Dr Clarke flew by military Chinook to Mallacoota with a small team of colleagues, some experts from Wollongong University, and representatives from DELWP and Parks Victoria.

Their goal was to rescue at least 15 of the 160 bristlebirds that live in that tiny pocket of Howe Flat.

Monash University biologist Dr Rohan Clarke says Howe Flat is one of the most biologically diverse places in Victoria. ( Supplied: Rowan Mott )

The group originally planned for five days of catching, but the continuous threat of bushfires reduced the mission to just a day and a half.

"There were literally planes water-bombing the fire only a couple of kilometres away while we were working," Dr Clarke said.

"It [the fire] was incredibly close; it burnt into the northern edge of the heath where the bristlebirds live."

In the end, the rescue team were able to take 15 bristlebirds back to Melbourne Zoo, to keep them safe in case the population left behind was wiped out by fire.

Three birds lost

Three of the 15 rescued bristlebirds did not survive long after arriving at Melbourne Zoo.

General manager of Threatened Species Programs at Zoos Victoria Craig Whiteford said all the birds were stressed and carried a heavy parasite load.

"Unfortunately we lost three of the birds over the first few days, but since then the remaining birds have settled in well. Our vets have done a fabulous job keeping everything in order," he said.

"We think that the three birds that died had a fungal infection in the lungs, and this fungus is just everywhere.

"They would have brought it with them from the wild, but given that they were stressed, they were caught, they were transported in small boxes on a boat, in a plane and in cars, and put into a new environment, it wasn't a surprise to us that we lost a few birds."

Once the bushfires in East Gippsland are completely extinguished, the 12 remaining bristlebirds will be returned to eastern Victoria — as long as their population and habitat has not been destroyed.

"We are hoping that we don't have to keep them to breed from," Mr Whiteford said.

"We're hoping to return them."

Almost unprecedented action

No other threatened species in Victoria had an insurance population flown out of the bushfire-affected areas, but extraction missions were considered for other animals.

"The Long-footed potoroo is one that we had our eye on fairly early, but it seems they are recovering, or at least being found on the fireground. That's based on intelligence from Parks Victoria," Mr Whiteford said.

Dr Clarke and the rescue team were flown to Mallacoota in a Chinook helicopter for their mission. ( Supplied: Tony Mitchell )

"Another one is the eastern ground parrot, that's one that we are concerned about.

"We really need to get in and do some assessments, and we are planning for spring extraction of spotted tree frogs."

Dr Clarke said the bristlebird rescue mission was a once-in-a-lifetime experience for him.

"A biologist doesn't normally get to climb into a Chinook. It's an incredible experience, but it's also really sobering," he said.

"We're at this point where we're not completely focused on the longer term, we're fighting this on the front to save things at the last moment."

'It's bad'

Environmental authorities still have not been able to fully assess East Gippsland to gauge exactly how badly affected the wildlife is.

"It's bad; we won't pretend otherwise," Mr Whiteford said.

"We haven't been able to get in to do all the assessments we need to do, because the fireground is still unsafe and the fires are still going.

"But a lot of minds are putting in their best efforts to try and work out how we can quickly and rapidly assess the remaining populations of threatened species, and we're doing planning around that."

Although the fires have been devastating for wildlife, Mr Whiteford said he had never seen the public more interested.

"From my perspective, having worked in fire spaces previously, this is the first time threatened species have gotten the profile they now have," he said.

"It's amazing, the community outpouring of interest, and that's manifested in donations.

"When we were extracting the birds, the community at Mallacoota was really interested and pleased that we were doing it. That was a delight."

One of the 12 bristlebirds now doing well at Melbourne Zoo. ( Supplied: Zoos Victoria )

Return mission

The 12 bristlebirds at Melbourne Zoo are now living in a specially designed aviary away from the public.

"Bristlebirds are fluffy to handle. All birds are fluffy, but these guys have extra filamentous feathers on their chest and back," Dr Clarke said.

"The most amazing thing about them is their really loud song. While they're cryptic and most people would never see them, if you know what their call is, you will hear them."

The birds will be held at Melbourne Zoo at least for another month.

"The fire is still really active. We can't put them back until the fire is completely out," Dr Clarke said.

"Hopefully this insurance population wasn't needed, if we haven't lost the site.

"If the fire burns and get worse, fortunately we have this insurance population."