Bushfires that destroyed massive areas of national park in the Hunter and elsewhere in NSW will have devastated wildlife, Tim Faulkner says.
Almost a million hectares have burnt in national parks within or closely connected to the Hunter, Rural Fire Service data shows.
This includes mega-fires in Yengo, Wollemi and Dharug national parks.
The notorious Wollemi fire, known as the "Gospers Mountain" blaze, has set a record for being the biggest forest fire in Australian history.
Mr Faulkner, the Australian Reptile Park general manager, said the effect of the fires on wildlife had been "catastrophic".
"It's unfathomable," said Mr Faulkner, who is also president of the Aussie Ark wildlife sanctuary in the Barrington Tops.
"This is a native wildlife state of emergency."
National parks have been hit by fire on the NSW east coast from Sydney to the Queensland border.
Federal Environment Minister Sussan Ley said 30 per cent of koalas on the NSW mid-north coast may have died in the fires.
While a big focus has been placed on koalas, many other species have been badly affected.
"When it comes to the hardest hit mammals, we're losing entire populations," Mr Faulkner said.
Mr Faulkner gave brush-tailed rock wallabies and platypuses as examples of species hit hard by the fires.
"Brush-tailed rock wallabies are critically endangered in parts and endangered in others. They had already been pushed within an inch of their lives. They're in real strife," he said.
The Wollemi National Park, stretching from the Hunter to the Blue Mountains, has more than 300 native species of mammals, reptiles, frogs and birds. Yengo National Park is home to a similar number.
Both national parks are part of the Greater Blue Mountains World Heritage Area. The brush-tailed rock-wallaby is a high priority for conservation management in both parks.
The NSW government is spending $100 million over five years to save threatened animals and plants from extinction from 2016 to 2021 under its Saving Our Species program.
Mr Faulkner said the bushfires had put species under further pressure. In some places, the fires had annihilated their habitat.
"I have empathy with government departments. The fires are still burning and staff and resources are committed to those fires," he said.
"Human life, infrastructure and stopping the fires from burning is the priority. But what about the wildlife? So much has been lost already and it won't come back without help."
He said a mass-scale combined effort was "needed now, not later".
"Many of the species affected were already at risk of extinction, such as koalas, brush-tailed rock-wallabies, turtles, quolls and platypus."
He said the effects of the fires on the largely unseen platypus population would be severe.
"People will say bushfires happen and it's natural. Sure, but what about the catastrophic nature of them?
"If it was just these fires and this drought, sure, but you've got all the other compounding effects these species were already suffering."
The country is in the midst of a wildlife catastrophe.
"Australia had the worst mammal extinction rate on Earth long before this fire and drought," he said.
The threatened tiger quoll was another species that the fires would have hammered.
"This entire fire range is tiger quoll habitat. They will have been annihilated.
"You're talking probably 50 to 100 endangered species that have been severely impacted."
Some of the other threatened species known to live in the national parks include the squirrel glider, grey-headed flying-fox, regent honeyeater, grey-crowned babbler, speckled warbler, brown treecreeper, broad-headed snake, black-chinned honeyeater, masked owl, barking owl, turquoise parrot, east-coast freetail-bat, black bittern and brush-tailed phascogale.
The NSW Office of Environment said many wildlife species can endure fires "by maintaining populations in refuge areas or habitats which have not been recently impacted by fire".
"The severity of the current bushfires combined with ongoing drought will have an impact on wildlife, including threatened species," a department spokesperson said.
"The extent of the impact will depend on the intensity of the fire and will vary from location to location."
The spokesperson said the NSW National Parks and Wildlife Service backed "licensed wildlife rehabilitation groups and individuals with funding and support during the search process [for affected wildlife]".
It added that it worked with the "many dedicated wildlife hospitals, carers and rehabilitation centres to care for any injured or displaced wildlife".
Aussie Ark and Australian Reptile Park staff have assessed drought- and fire-affected areas in the greater Barrington region.
"The results witnessed by staff were devastating. The wildlife organisations had to relocate 50 endangered Hunter River turtles from dried up waterways," Mr Faulkner said.
"Ten platypus were found and transferred, with five requiring veterinary care."
They also monitored and provided food drops for brush-tailed rock-wallabies and assessed the possibility of emergency intervention for the critically endangered Manning River turtle.
"Food drops and artificial water stations should happen. This has been well trialled before in areas affected by fire," he said.
"There really needs to be a bigger response, but it's needed now. In six months time, they're all dead."
He said some animals would survive the fires and drought, but they still faced the "massive problem of feral pests".
"Can you imagine how much easier they will be for foxes and cats to hunt?
"The animals are exposed and vulnerable. That's what's happening now."
He said the wildlife crisis needs "a thousand champions" from public-private partnerships, corporations, government, philanthropic and conservation groups and the community.
He said the focus over the summer should be on areas where water had dried up.
"I don't think we can plan on it raining," he said.
He said the fires had caused a "catastrophic loss of biomass" for many common species.
"Where [for example] do the honeyeaters go? What do they eat? Everything is displaced," he said.
He said this catastrophic loss would have a "compounding effect".
"I view it like a tide. The tide is coming, whether it's climate change, pollution, feral pests, fire or drought.
"Every time the animals poke their heads up for a breath of air, bang, another wave hits them."
He wonders whether the forests and species will be able to recover. He was particularly concerned that rainforests and so-called "wet forests" had burned in northern parts of the state.
"We've lost Antarctic beech forest. It's Gondwanian. It's cool temperate forest," he said.
These ancient world-heritage areas stretch in pockets from the Barrington Tops to the Gold Coast. They are the last remnants of the supercontinent Gondwana that broke up about 180 million years ago. Their ecology has been likened to the time of the dinosaurs. Usually these forests are too wet to burn. But sections in northern NSW and southern Queensland burned in the recent fires, highlighting the threat of climate change.
These areas are home to half of Australia's plant species and a third of its birds and mammals. They help protect dozens of threatened species.
He said these types of forests were "not fire resilient".
"When they die, they die."
The Barrington Tops world heritage area has, so far, escaped fire. The Aussie Ark wildlife sanctuary is also in the Barrington Tops. The non-profit organisation establishes predator-proof and fenced sanctuaries for threatened species such as the Tasmanian devil, eastern quoll and long-nosed potoroo. A koala sanctuary is planned to be established.
Mr Faulkner is worried about fire threatening Aussie Ark's species.
"We are in a really complementary spot, on the north-west side of the Barringtons. Fire kind of has to start on us to reach us," he said.
"It's very unlikely to blow our way. There were four fires up there threatening the Barringtons just weeks ago. They were well controlled. It's largely been unscathed."
This was partly down to luck, he said, which "makes the protection of critical habitat all the more important".
He said the same type of fires won't happen again next year because "there's nothing left to burn".
"But the wildlife and people are suffering. The Earth is suffering. This doesn't end when the flames go out," he said.
"What is the response from governments?"