Animal response to a bushfire is astounding. These are the tricks they use to survive



Some animals stay put after a bushfire and rebuild their populations from charred landscapes.
LUKAS COCH/AAP

Dale Nimmo, Charles Sturt University

Have you ever wondered how our native wildlife manage to stay alive when an inferno is ripping through their homes, and afterwards when there is little to eat and nowhere to hide? The answer is adaptation and old-fashioned ingenuity.

Australia’s bushfire season is far from over, and the cost to wildlife has been epic. A sobering estimate has put the number of animals killed across eastern Australia at 480 million – and that’s a conservative figure.

But let’s look at some uplifting facts: how animals survive, and what challenges they overcome in the days and weeks after a fire.

This possum decided to flee a bushfire in the NSW Hunter region in 2018, but many other animals stay put.
AAP/Darren Pateman

Sensing fire

In 2018, a staff member at Audubon Zoo in the United States accidentally burned pastry, and noticed something peculiar. In nearby enclosures ten sleepy lizards, or Tiliqua rugosa, began pacing and rapidly flicking their tongues. But sleepy lizards in rooms unaffected by smoke remained burrowed and calm.

It was obvious the lizards sensed the smoke from the burnt pastry, probably through olfaction, or sense of smell (which is enhanced by tongue flicking). So the lizards were responding as they would to a bushfire.

In Australia, experiments have shown smoke also awakens Gould’s long-eared bats and fat-tailed dunnarts, enabling their escape from fire.




Read more:
Bushfires have reshaped life on Earth before. They could do it again


Animals also recognise the distinct sounds of fire. Reed frogs flee towards cover and eastern-red bats wake from torpor when played the crackling sounds of fire.

Other species detect fire for different reasons. Fire beetles from the genus Melanophila depend on fire for reproduction, as their larvae develop in the wood of burned trees. They can detect fire chemicals at very low concentrations, as well as infrared radiation from fires.

The beetles can detect very distant fires; one study suggests individuals of some species identify a fire from 130km away.

Stay or go?

Once an animal becomes aware of an approaching fire, it’s decision time: stay or go?

It’s common to see large animals fleeing a fire, such as the kangaroos filmed hopping from a fire front in Monaro in New South Wales a few days ago. Kangaroos and wallabies make haste to dams and creek lines, sometimes even doubling back through a fire front to find safety in areas already burned.

Other animals prefer to stay put, seeking refuge in burrows or under rocks. Smaller animals will happily crash a wombat burrow if it means surviving a fire. Burrows buffer animals from the heat of fires, depending on their depth and nearby fuel loads.

From here, animals can repopulate the charred landscape as it recovers. For example, evidence suggests populations of the agile antechinus (a small carnivorous marsupial) and the bush rat recovered primarily from within the footprint of Victoria’s Black Saturday fires.

Avoiding fire is only half the battle

The hours, days, and weeks after fire bring a new set of challenges. Food resources will often be scarce, and in the barren landscape some animals, such as lizards and smaller mammals, are more visible to hungry predators.

Birds of prey arrive quickly at fires. Several species in northern Australia have been observed intentionally spreading fires by transporting burning sticks in their talons or beaks.




Read more:
Making sense of Australia’s bushfire crisis means asking hard questions – and listening to the answers


One US study published in 2017 recorded a seven-fold increase in raptor activity during fire. They begin hunting as the fires burn, and hang around for weeks or months to capitalise on vulnerable prey.

Feral cats can travel kilometres in search of vulnerable prey in a burnt-out landscape.
HUGH MCGREGOR

In Australia, introduced predators can also be drawn to fires. Feral cats have been observed travelling up to 12.5km from their home ranges towards recently burned savanna ecosystems, potentially drawn by distant smoke plumes promising new prey.

A 2016 study found a native rodent was 21 times more likely to die in areas exposed to intense fire compared to unburned areas, mostly due to predation by feral cats. Red foxes have an affinity for burned areas too.

So should a little critter hunker down, or begin the hazardous search for a new home?

Staying put

Perhaps because of the risks of moving through an exposed landscape, several Australian mammals have learnt to minimise movement following fire. This might allow some mammal populations to recover from within a fire footprint.

Native mammals have been found hiding in beds of ash after fires.




Read more:
Koalas are the face of Australian tourism. What now after the fires?


Short-beaked echidnas seek refuge and, when finding it, lower their body temperature and limit activity, so reducing the amount of food they need for energy. Despite their spiny defences, echidnas have been found more often in the stomachs of foxes following fire, so staying put in a little refuge is a good move.

Small marsupials such as brown and yellow-footed antechinus also use torpor to suppress their energy use and therefore the need to seek food.

Some animals can flee a fireground, while others use bush-smarts to stay put.
Jeremy Piper/AAP

Running the gauntlet

Not all wildlife have adapted to stay put after a fire, and moving in search of a safe haven might be the best option.

Animals might take short, information-gathering missions from their refuges into the fireground before embarking on a risky trek. They may, for example, spot a large, unburned tree that would make good habitat, and so move towards it. Without such cues to orient their movement, animals spend more time travelling, wasting precious energy reserves and increasing the risk of becoming predator food.

A dead bird at a Victorian property on January 4, 2019. The ecological toll of the bushfires is immense.
James Ross/AAP

Survival is not assured

Australia’s animals have a long, impressive history of co-existing with fire. However, a recent study I led with 27 colleagues considered how relatively recent threats make things much harder for animals in fire-prone landscapes.

Some native species are not accustomed to dealing with red foxes and feral cats, and so might overlook cues that indicate their presence, and make the bad decision to move through a burned landscape when they should stay put.




Read more:
Listen to your people Scott Morrison: the bushfires demand a climate policy reboot


When fires burn habitat in agricultural or urban landscapes, animals might encounter not just predators but vehicles, livestock and harmful chemicals.

And as this bushfire season has made brutally clear, climate change is increasing the scale and intensity of bushfires. This reduces the number of small refuges such as fallen logs, increases the distance animals must cover to find new habitat and leaves fewer cues to direct them to safer places.

We still have a lot to learn about how Australia’s wildlife detect and respond to fire. Filling in the knowledge gaps might lead to new ways of helping wildlife adapt to our rapidly changing world.The Conversation

Dale Nimmo, Associate professor/ARC DECRA fellow, Charles Sturt University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

In fact, there’s plenty we can do to make future fires less likely



It’s in our power to influence the climate by influencing the nations who help determine the climate.
Victorian government

Peter Martin, Crawford School of Public Policy, Australian National University

One of the dominant ideas buzzing around the internet is that there’s little we can do to escape the prospect of more frequent and worse bushfires – ever.

That’s because there’s little we can do to slow or reverse the change in the climate.

Australia accounts for just 1.3% of global emissions. That’s much more than you would expect on the basis of our share of world’s population, which is 0.33%. But even if we stopped greenhouse gas emissions as soon as we could and started sucking carbon back in (as would be possible with reafforestation) it’d make little difference to total global emissions, which is what matters – or so the argument goes.

But this argument ignores the huge out-of-proportion power we have to influence
other countries.

There’s no better indicator of that than in Ross Garnaut’s new book Super-power: Australia’s low-carbon opportunity.




Read more:
The bushfires are horrendous, but expect cyclones, floods and heatwaves too


We’re more important than we think

The cover of ‘Super-power’ by Ross Garnaut.
Supplied

Garnaut conducted two climate change reviews for Australian governments, the first in 2008 for the state and Commonwealth governments, and the second in 2011 for the Gillard government.

In the second, he produced two projections of China’s emissions, based on what was known at the time.

One was “business as usual”, which showed continued very rapid increases. The other took into account China’s commitments at the just-completed 2010 United Nations Cancun climate change conference.

China’s annual emissions matter more than those of any other country – they account for 27% of the global total, which is a relatively new phenomenon.

The bulk of the industrial carbon dioxide already in the atmosphere was put there by the United States and the Soviet Union, who have been big emitters for much longer.

Egged on by the US Obama administration and by governments including Australia’s under Julia Gillard, China agreed at Cancun to slow its growth in emissions, and at the Paris talks in 2015 hardened this into a commitment to stabilise them by 2030.

The extraordinary graph

Garnaut’s 2011 projections showed growth moderating as a result of China’s commitment, which was at the time a cause for optimism.

When he returned to the numbers in 2019 to prepare his book, he was stunned. Egged on by the example of countries including the US and Australia, China had done far, far better than either “business as usual” or its Cancun commitments. Instead of continuing to grow rapidly, or less rapidly as China had said they would, they had almost stopped growing.

The graph, produced on page 29 of Garnaut’s book, is the most striking I have seen.



Since 2011, China’s emissions have been close to spirit-level flat. They climbed again only from 2017 when, under Trump in the US and various Coalition prime ministers in Australia, the moral pressure eased.

From the start of this century until 2011, China’s consumption of coal for electricity climbed at double-digit rates each year. From 2013 to 2016 (more than) every single bit of China’s extra electricity production came from non-emitting sources such as hydro, nuclear, wind and sun.

There are many potential explanations for the abrupt change. Pressure from nations including the US and Australia is only one.

What happened once could happen again

And there are many potential explanations for China’s return to form after Trump backslid on the Paris Agreement and Australia started quibbling about definitions.
An easing of overseas pressure is only one.

But, however brief, the extraordinary pause gives us cause for hope.

Australia can matter, in part because it is hugely respected in international forums for its technical expertise in accounting for carbon emissions, and in part because of its special role as one of the world’s leading energy exporters.

Garnaut’s book is about something else – an enormous and lucrative opportunity for Australia to produce and export embedded energy sourced from wind and the sun at a cost and scale other nations won’t be able to match.




Read more:
Australia could fall apart under climate change. But there’s a way to avoid it


Some of it can be used to convert water into hydrogen. That can be used to turn what would otherwise be an intermittent power supply into a continuous one that enables around-the-clock production of the green steel, aluminium, and other zero-emission products Japan, Korea, the European Union and the United Kingdom are going to be demanding.

It’s a vision backed by Australia’s chief scientist.

It wouldn’t have been possible before. It has been made possible now by the extraordinary fall in the cost of solar and wind generation, and by something just as important – much lower global interest rates. Solar and wind generators cost money upfront but cost very little to operate. Interest rates are the cost of the money upfront.

At least three consortia are drawing up plans.

There’s not much to lose

There’s much that needs to be done, including establishing the right electricity transmission links. But Garnaut believes it can all be done within the government’s present emissions policy, helping it achieve its emission reduction targets along the way.

What’s relevant here is that moving to ultra-low emissions would do more. It could give us the kind of outsized international influence we are capable of. It could help us make a difference.The Conversation

Peter Martin, Visiting Fellow, Crawford School of Public Policy, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Batteries made with sulfur could be cheaper, greener and hold more energy


Mahdokht Shaibani, Monash University

Lithium-ion batteries have changed the world. Without the ability to store meaningful amounts of energy in a rechargeable, portable format we would have no smartphones or other personal electronic devices. The pioneers of the technology were awarded the 2019 Nobel Prize for chemistry.

But as society moves away from fossil fuels, we will need more radical new technologies for storing energy to support renewable electricity generation, electric vehicles and other needs.




Read more:
Charged up: the history and development of batteries


One such technology could be lithium-sulfur batteries: they store considerably more energy than their lithium-ion cousins – in theory as much as six times the energy for a given weight. What’s more, they can be made from cheap materials that are readily available around the world.

Until now, lithium-sulfur batteries have been impractical. Their chemistry allows them to store so much energy that the battery physically breaks apart under the stress.

However, my colleagues and I have engineered a new design for these batteries which allows them to be charged and discharged hundreds of times without breaking down. We hope to have a commercial product ready in the next 2–4 years.

What’s so good about sulfur?

Lithium-ion batteries require minerals such as rare earths, nickel and cobalt to produce their positive electrodes. Supply of these metals is limited, prices are rising, and their mining often has great social and environmental costs.

Industry insiders have even predicted serious shortages of these key materials in the near future, possibly as early as 2022.

In contrast, sulfur is relatively common and cheap. Sulfur is the 16th most abundant element on Earth, and miners produce around 70 million tonnes of it each year. This makes it an ideal ingredient for batteries if we want them to be widely used.

What’s more, lithium-sulfur batteries rely on a different kind of chemical reaction which means their ability to store energy (known as “specific capacity”) is much greater than that of lithium-ion batteries.

The prototype lithium-sulfur battery shows the technology works, but a commercial product is still years away.
Mahdokht Shaibani, Author provided

Great capacity brings great stress

A person faced with a demanding job may feel stress if the demands exceed their ability to cope, resulting in a drop in productivity or performance. In much the same way, a battery electrode asked to store a lot of energy may be subjected to increased stress.

In a lithium-sulfur battery, energy is stored when positively charged lithium ions are absorbed by an electrode made of sulfur particles in a carbon matrix held together with a polymer binder. The high storage capacity means that the electrode swells up to almost double its size when fully charged.

The cycle of swelling and shrinking as the battery charges and discharges leads to a progressive loss of cohesion of particles and permanent distortion of the carbon matrix and the polymer binder.

The carbon matrix is a vital component of the battery that delivers electrons to the insulating sulfur, and the polymer glues the sulfur and carbon together. When they are distorted, the paths for electrons to move across the electrode (effectively the electrical wiring) are destroyed and the battery’s performance decays very quickly.

Giving particles some space to breathe

A CT scan of one of the sulfur electrodes shows the open structure that allows particles to expand as they charge.
Mahdokht Shaibani, Author provided

The conventional way of producing batteries creates a continuous dense network of binder across the bulk of the electrode, which doesn’t leave much free space for movement.

The conventional method works for lithium-ion batteries, but for sulfur we have had to develop a new technique.

To make sure our batteries would be easy and cheap to manufacture, we used the same material as a binder but processed it a little differently. The result is a web-like network of binder that holds particles together but also leaves plenty of space for material to expand.

These expansion-tolerant electrodes can efficiently accommodate cycling stresses, allowing the sulfur particles to live up to their full energy storage capacity.




Read more:
A guide to deconstructing the battery hype cycle


When will we see working sulfur batteries?

My colleagues Mainak Majumder and Matthew Hill have long histories of translating lab-scale discoveries to practical industry applications, and our multidisciplinary team contains expertise from materials synthesis and functionalization, to design and prototyping, to device implementation in power grids and electric vehicles.

The other key ingredient in these batteries is of course lithium. Given that Australia is a leading global producer, we think it is a natural fit to make the batteries herea.

We hope to have a commercial product ready in the next 2–4 years. We are working with industry partners to scale up the breakthrough, and looking toward developing a manufacturing line for commercial-level production.The Conversation

Mahdokht Shaibani, Research Fellow, Mechanical & Aerospace Engineering, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

‘This crisis has been unfolding for years’: 4 photos of Australia from space, before and after the bushfires



Use the slider tool in the images below to see before and after NASA satellite images of Australia’s fire and drought effects.
NASA

Molly Glassey, The Conversation; Sunanda Creagh, The Conversation, and Wes Mountain, The Conversation

Editor’s note: We pulled four before-and-after-images from NASA’s Worldview application, and asked bushfire researcher Grant Williamson to reflect on the story they tell. Here’s what he told us:


I’ve been studying fires for more than a decade. I use satellite data to try to understand the global and regional patterns in fire – what drives it and how it will shift in the future as our climate and land use patterns change.

When I look at these images I think: this is a crisis we have seen coming for years. It’s something I have been watching unfold.

Look at the sheer scale of it. Seeing this much fire in the landscape in such a broad area, seeing so much severe fire at once, this quantity and concentration of smoke – it is astonishing. I haven’t seen it like this before.

November 1, 2019 and January 3, 2020

@media only screen and (max-width: 450px) {
iframe.juxtapose { height: 400px; width: 100%; }
}
@media only screen and (min-width: 451px) and (max-width: 1460px) {
iframe.juxtapose { height: 590px; width: 100%; }
}

In this comparison, you can see November last year versus now. In the present picture (on the right hand side) you can see a vast quantity of intense fires currently burning right down the eastern seaboard and a huge amount of smoke. It’s been blowing out across toward New Zealand for weeks now.

The scale of the current fires is definitely unusual. In a typical year, you might see, for example, a large fire in the alps (near Mount Kosciuszko) or in the Blue Mountains – but they would be isolated events.

What’s striking here is that there is so much going on at once. I have never seen it like this before.

Black Saturday smoke, Feburary 8, 2009 and the 2019-2020 bushfires smoke, January 3, 2020

This one is comparing two smoke events: one from Black Saturday and one from the current fires. In both cases, huge quantities of smoke was released. Both times, the sort of forest burning is very dense, there is a lot of wet eucalypt forest here which naturally has a high fuel load and that’s creating all that smoke. This type of forest only burns during extreme weather conditions.

Simply due to the scale of it and the fact that it’s been going on so long, I would say the current event is worse than Black Saturday, in terms of the quantity of smoke.

East Australia, 10 years ago vs today

In this image, we can the impact of drought. A decade ago, on the left hand side, it was clearly quite green along eastern Australia. That green shows there is a lot of growing vegetation there: pasture crops, grasses and a very wet environment.

If you compare that to the current year, on the right hand side, you can see it’s now extremely brown and extremely dry. There’s not much in the way of vegetation. That’s a result of drought and high temperatures.

Kangaroo Island, 2 months ago vs today

In this image, you can see Kangaroo Island two months ago on the left hand side, versus today.

The main thing I note here is the drying. The “before” image is so much greener than the “after” image. So there’s a real lack of rainfall that’s driving fire severity in this area. You can really see how much the island has dried out.


This has been an extraordinary year for climate and weather, and that’s manifesting now in these unprecedented bushfires. It’s not over yet.

But what’s important is the lessons we draw from this crisis and doing as much as we can to reduce the risk in future.


Grant Williamson is a Tasmania-based researcher with the NSW Bushfire Risk Management Research Hub.The Conversation

Molly Glassey, Digital Editor, The Conversation; Sunanda Creagh, Head of Digital Storytelling, The Conversation, and Wes Mountain, Multimedia Editor, The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.