Share All sharing options for: An Australian ecologist explains just how bad the fires are for wildlife

Australia’s wildfires have been terrifying to watch. It’s one of the country’s worst fire seasons on record: 17.9 million acres have burned. That’s an area larger than West Virginia, and more than nine times the area that burned in California in 2018, the state’s most destructive year for wildfires.

People have been forced out of their homes, and at least 27 have died. It’s a serious humanitarian disaster. But perhaps the greatest damage is to wildlife. An estimated 1 billion animals have been lost, and scientists fear long-term damage to many sensitive ecosystems.

Australia is one of the great biodiversity hot spots in the world. The island continent was isolated from the rest of the world for millions of years, allowing evolution to take strange new paths, with little human influence until fairly recently. Before the fires, its great diversity was already threatened due to invasive species, habitat destruction, and climate change, according to Australia’s science research agency, CSIRO. Now, ecologists fear severe ecological consequences from so much land being burned at once.

Sarah Legge is an ecologist at the Australian National University who studies how species respond to fire. In an interview this week, she explained just how bad the situation is for Australia’s wildlife — and which species will be most severely impacted. It’s not the koala (a staggering 8,000 of which have died). It’s the lesser-known species that live in small areas that have been totally engulfed.

“Hundreds of species have been affected by these fires,” Legge says. “That includes many dozens of threatened species; some of these will be brought to the brink of extinction as a result of this event. And if they’re not made extinct by this event, I think this is the beginning of the end for them. Because this event will reoccur. It’s awful. It will be ecosystem collapse in a lot of cases. And we’re not exactly sure what we’ll end up with at the end of it all.”

This interview has been edited for length and clarity.

Brian Resnick

As you’ve been watching this situation evolve and grow, how do you tell the story of what’s going on?

Sarah Legge

Fire is a natural part of many Australian habitats. So many Australian plants and animals are adapted to cope with fire. But they’re not adapted to cope with fire of this scale and this intensity. These fire events are unprecedented.

And the fire has also burned some habitats that just ... don’t burn normally. Some of the [UNESCO] listed subtropical rainforests along the Queensland-New South Wales border have burned. And we don’t even know how it can recover from fire because in our experience, in our living knowledge, they don’t burn.

Brian Resnick

You said some of these species are adapted to fire, but not of this scale. How do some species normally respond to fire, and why wouldn’t they be able to use those strategies now?

Sarah Legge

Normally, just small parts of the overall distribution [of where the species lives] would be affected. The fire might affect 5 percent of the distribution, not 100 percent. And the fire would be lower in intensity.

So [a species] might [hide] in a rocky pile where the radiant heat of the fire doesn’t kill it outright. It could survive the fire event, and there’s still bits of habitat in the immediate vicinity that it can use. That’s not the case this time.

Brian Resnick

Do you have examples of this in mind?

Sarah Legge

You got species like the long-footed potoroo — that’s a small marsupial that lives in the forest of East Gippsland in Victoria. That’s a fire-prone environment, so that animal has evolved with fire over many millennia. But now its entire distribution has been nuked in one intense event.

Another good example is the Kangaroo Island dunnart, which is a small carnivorous marsupial that lives on Kangaroo Island. Almost all of the national park on Kangaroo Island has been burnt.

This animal is already very rare. It shelters under the foliage of grass trees. Those grass trees have been incinerated. So any dunnart sheltering under there will have been killed. Whereas in a lower-intensity fire, some of the grass trees wouldn’t have burned, and certainly not all of the distribution of the dunnart would have burned in one go.

Brian Resnick

There’s been a lot of attention paid to the number of koalas being killed in the fire. How does their situation compare to these other species?

Sarah Legge

Anything with a small distribution is at an extreme risk. The images we see of suffering koalas are horrible. But they have a much bigger distribution, so this species probably hasn’t been brought to the brink in the same way that species with smaller distributions may have.

The silver-tailed antechinus, another carnivorous marsupial that lives in Queensland — its entire distribution pretty much has been burned. Glossy black cockatoos on Kangaroo Island, their distribution is being burned.

Brian Resnick

Is the fear that a lot of the damage won’t be salvageable? How should we think about what happens next, and what can be done to help these species?

Sarah Legge

A lot of us are feeling shell shock at the moment. There are some priorities. One is we need to prioritize the species that we’re most worried about, and then go out and look for them. Are they still there? Are there any bits of habitat in their distributions that didn’t burn?

And if we can find those bits of habitat, we need to protect them from further fire, from predation from feral predators and weed incursion — all these things that fire amplifies. There are things we can do to help them hang on for a few years.

But apart from that, people are talking about strategic feeding [of species], strategic setting up nest boxes. It won’t always be the best thing to do. But there will be cases where those kind of very intensive and small-scale actions could help. And they’ll certainly make people feel better.

Brian Resnick

What happens to these environments after the fires cease?

Sarah Legge

As well as the immediate mortality that’s caused by the fire, there’s going to be ongoing mortalities as the result of starvation — there will be nothing to eat — and the lack of shelter.

After an intense fire event, feral predators including foxes and cats are actually attracted to that fire-affected area to hunt there. Their hunting efficiency increases quite dramatically because the native animals have got nowhere to hide. So cats will come in from 20, 30 kilometers away to hunt in a recently burned area, and they mop up all the native animals that are left there over the next few months.

Brian Resnick

What draws these predators to the fire?

Sarah Legge

It’s amazing. They can travel quite a big distance to get to a fire event. We assume they are following the smoke. They might see smoke. But it’s incredible that, a) they know it’s worth going, and b) where to go.

Brian Resnick

On the bright side: Are there any interesting research opportunities that will result from the fire?

Sarah Legge

Oh, my gosh. To be honest, I don’t think so. Obviously, there has been research in the past on the impact on extreme fire events, but they’ve all been smaller in scale. An event like this, I don’t think anyone is thinking about the research opportunities. I think they’re thinking about the catastrophe and how we can limp through it and minimize the damage.

Brian Resnick

Is there any aspect of this story that you think needs more attention?

Sarah Legge

Obviously, the driver here is climate change, leading to extended drought and high temperatures. Australia is looking at 3 to 4 degrees of warming. I’m frightened to even imagine the country in that scenario. If this fire event is what we experienced with 1 degree of warming, what on earth are we going to be experiencing at 3 or 4 degrees of warming? It’s terrifying.

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