Australia’s wildfires have now burned more than 15.5 million acres across the continent, leaving at least 25 people dead.

In addition to the catastrophic impact on life and human health, the fires have also left an estimated 1.25 billion animals dead, according to the World Wildlife Fund, which arrived at this figure based on University of Sydney Professor Chris Dickman’s work.

“We’re all devastated. Devastated, but in the really fortunate position that we’ve got the kind of skilled staff that can go into the field and really make a difference,” said Michelle Lang, general manager at Zoos Victoria, which operates three zoos in the state, as well as a host of other conservation programs.

Organizations like Zoos Victoria have found themselves pressed into de facto emergency relief agencies on the front lines of saving impacted animals. Two Zoos Victoria veterinary staff members were recently given permission to go into fire zones in order to treat koalas and other wildlife.

“Despite their injuries and trauma, the bravery shown by the koalas and wildlife at Mallacoota is inspiring,” Dr. Leanne Wicker, who went into the bush, said in a press release.

According to Lang, Zoos Victoria was “pretty well prepared” to engage in their response role, considering the sheer scale of the fires, because of previous programs they have implemented, such as their Marine Response Unit, which was created 2013 responds to calls for assistance with vulnerable animals on a daily basis.

Lang pointed out that many of the most decimated wildlife populations will be, “small, unknown, unglamorous animals that are so vital to our ecosystem and our chain of biodiversity.

“Some species, there were only 2,000 of them before the fires, so we hate of think how many of them will be left after this,” she said.

In addition to the iconic koala bears, other impacted animals across the continent include the nabarlek, bilby, northern bettong, gouldian finch, numbat, and wiliji.

Dr. Stuart Blanch, Senior Manager of Land Clearing and Restoration at WWF-Australia, identified the long-footed potoroo, mountain pygmy possum, yellow-bellied glider and brush-tailed rock wallaby, as well as the regent honeyeater and glossy black cockatoo, which are both critically endangered, as being particularly at-risk, due to the destruction of their habitats.

Blanch told USA Today earlier this week that, “Up to 30% of koalas (as many as 8,400 koalas) may have perished during fires on the mid-north coast of New South Wales. This is a devastating blow for a species already in decline, due to ongoing excessive tree-clearing for agricultural and urban development, and pushes the species closer to becoming an endangered species.

“This has the potential to hasten koalas’ slide towards extinction in the wild in eastern Australia,” he said.

Contextualizing the impact of these fires, WWF-Australia CEO Dermot O’Gorman said many of the country’s forests and animals are facing a decades-long recovery, if the latter are able to bounce back at all.

“… some species may have tipped over the brink of extinction,” O’Gorman said in a written statement.

Zoos Victoria, which launched a $30 million initiative to save 20 species from extinction in 2015, has since grown that number to 27. They also operate conservation programs in six countries and can point to several successes such as their breeding of the critically endangered Baw Baw frog last year, and releasing dozens of critically endangered orange-bellied parrots into the wild. On the strength of this experience, they are anticipating which steps will be required after the fires die down. Lang said that potential scenarios include supplementary feeding programs for animals that survive, but are faced with a lack of food, animals that need to be protected from an over-population of predators, new holding areas, specific food items, habitat restoration, and extra staff.

During this critical care phase, funds going to Zoo Victoria now will support vets during their week-long forays into the field in the upcoming months as well as ensuring that animals receive uninterrupted care at their facilities.

100% of donated funds donated to Zoos Victoria will go directly to bushfire-impacted wildlife.

“We’ve been really humbled by the support that we’ve received so far. Some people give $5, and that’s really fantastic. We’re asking people to think about wildlife that’s really suffering,” Lang said.

Though Zoos Victoria is currently responding to alleviate the suffering of animals, and planning for possible eventualities, the full scope of the damage at the moment, to say nothing of what the reality will be after the fires die down, is unknown.

“We don’t actually know what we’re dealing with,” Lang said.