Australia is in an extinction crisis

  • We have wiped out more mammals than any other country.
  • Threatened birds have disappeared from two-thirds of the continent.
  • There are now more foreign plants than native ones.
  • The national threatened species list is more than 2,000 species long.
  • And the state of the environment has been characterised as “poor and deteriorating”.

And yet, 84% of Australians think that nature here is in excellent, good or fair shape.

There is a Cradle Mountain-sized gap between perception and reality about Australian nature. 

An important step in bridging this gap is to name the specific threats to nature.

By naming the main threats to our shared big backyard, we can see that each of them is surmountable, and begin to realise alternative ways of doing things that help restore nature to better health than it’s currently in.

What's behind nature's decline?

1. Habitat destruction

When we bulldoze animals’ homes, they have nowhere to survive. It’s that simple.

And Australia is a world leader in destroying habitat. 

We’re the only developed nation on the list of global deforestation hotspots, an unenviable title that we’ve earned thanks to a deadly combination of colonialism, broken national environment laws and unfettered destructive practices by industries. 

In the last decade, Australia’s Federal Government has approved the demolition of more than 200,000 hectares of threatened species habitat. 

The koala, an international symbol of Australia, has lost more habitat to federally-approved destruction than any other animal.

Native vegetation cleared to make way for agricultural activities west of Roma, Queensland. Credit: Dean Sewell

While 72% of the total habitat federally-approved for destruction was for mining, this is just one part of the story. Vegetation is also cleared to make way for agricultural expansion and urban sprawl.

Agriculture accounts for 55% of Australia’s land use, mostly for grazing cattle (340 million hectares) and for cropping (66 million hectares). The destruction of nature to make way for agricultural activities such as these is rarely assessed under national environment law, meaning the real amount of habitat cleared is much larger than records indicate. 

In fact, research by ACF’s Investigations Unit and Dr. Martin Taylor revealed that 400,000 hectares of threatened species habitat was annihilated to make way for sheep and cattle grazing in Queensland alone in just one year. 

What’s more, the report found that none of this clearing was approved or even assessed under Australia’s national environment law. 

And perhaps even more incredibly, native forest logging is exempt from these laws altogether. It’s little wonder that Australia’s so-called environment laws have been labelled as needing “fundamental reform”.

Cattle grazing dominates land use in Australia. Credit: Matt Palmer

Not only does habitat destruction leave native animals without the shelter and food they need to survive and raise young, it also causes declines in soil health and is a contributor to greenhouse gas emissions.

So while species, ecosystems and the climate are suffering under the weight of multiple and interacting pressures, habitat destruction makes all other threats more acute.

As described by scientists who analysed the main pressures on Australia’s threatened plants and animals “habitat is the most fundamental need of species, and its continued loss will result in ongoing declines regardless of how well other threats are managed”.

This is echoed by researchers studying the critically endangered regent honeyeater—a bird that was once common across eastern Australia, but has now been reduced to such small populations that it is losing its song

“Habitat is king,” they say, and with 90% of the regent honeyeater’s preferred woodland habitat having been converted to agricultural land since colonisation, modelling shows we must do much more to secure their home, otherwise all other conservation efforts will be pointless.

This is not unique to the regent honeyeater. 

When looking at all the threats to Australia’s imperilled wildlife, mitigating the impacts of habitat destruction, fragmentation and degradation will benefit the greatest number of taxa overall.

Once common across eastern Australia, the regent honeyeater is now critically endangered with only around 100 pairs remaining. Credit: Wikimedia

2. Invasive species

When Europeans arrived on the continent today known as Australia, they introduced foreign plants, animals, pathogens and diseases. The result has been an ecological disaster.

Species here have evolved largely in isolation since Australia separated from Gondwana about 40 million years ago, creating high levels of endemism that contributes to our status of one of the world’s 17 megadiverse countries. 

Over 80% of Australia’s plants, mammals, frogs and reptiles are completely unique to this island and not equipped to deal with introduced predators like cats, foxes and yellow crazy ants, creatures that change the landscape like rabbits, horses and pigs or weeds that outcompete native plants like the European blackberry.

In 2018, invasive species were listed as impacting 82% of Australia’s threatened native species.

While it is difficult to comprehend the scale and variety of problems they cause, the CSIRO has identified those responsible for the most damage, coining them ‘the worst of a bad bunch’. 

These include but are not limited to:

  • European rabbits - the prolific breeder infests two thirds of the continent, constitutes the biggest single menace to threatened species and costs an average of $216 million per year in lost farming productivity.
  • Feral cats - are estimated to kill 465 million native mammals, 272 birds, 92 million frogs and 446 million reptiles every year.
  • Cane toads - have invaded more than a million square kilometres of Australia and are fatally toxic to many native predators like goannas and northern quolls.
  • European carp - are now found in all states and territories except the Northern Territory. They compete with native fish for food and damage aquatic habitats like the Murray-Darling Basin.
  • Chytrid fungus - a fungal pathogen that kills frogs around three weeks after infection. It has already wiped out 90 amphibian species worldwide including 5 from Australia.
  • European blackberry - introduced for its fruit in the mid 1800s, this prickly thicket now covers nearly nine million hectares of land in Australia where it smothers native shrubs, provides shelter for other invasive species like foxes and rabbits and even increases the threat of fire.

Australia has between 2 and 6 million feral cats. They have already contributed to the extinction of 27 native species and threaten the survival of 124 more. Credit: Brian Wangenheim

Not only are invasive species threatening Australia’s world famous biodiversity, they are also an economic burden, costing us $24.5 billion every year in lost productivity and control measures.

3. Impacts of climate change

Australia is the fourteenth biggest emitter of greenhouse gases in the world, and many of our species and ecosystems are particularly vulnerable to the changing climates that these emissions create.

Climate change impacts on Australian nature in a number of ways. Perhaps the most obvious is via severe and more frequent extreme weather events like fires, heatwaves, droughts, storms and floods that alter species' habitats and even entire ecosystems.

For example, the Black Summer bushfires of 2019-2020 burned through around 97,000 square kilometres of vegetation in eastern Australia—home to 832 species of native vertebrates. 

The situation is even worse for invertebrates, 800 of which lost more than 50% of their known range.

Overall, three billion mammals, birds, frogs and reptiles are estimated to have been killed or displaced by the megafires.

But it’s not just fires. Events like heatwaves which are trending to become more frequent and severe under climate change can have swift and devastating impacts. 

The Black Summer bushfires in East Gippsland, Victoria.70 vertebrate taxa had more than 30% of their habitat burned by these fires in 2019-2020. Credit: Nick Bauer

In 2014, at least 45,500 black, grey-headed and little red-flying foxes died in a single day when temperature records were broken at nine locations in Queensland. In this way, climate change can impact species at a population level in the relative blink of an eye.

And heatwaves aren’t limited to the land. The 2022 State of the Climate Report confirmed that increasing greenhouse gas emissions have caused hotter and more acidic oceans, resulting in increased marine heatwaves and die-offs of corals, mangroves and kelp forests.

The grey-headed flying fox is a cornerstone species and particularly vulnerable to impacts from climate change like increasing heat waves. Credit: shellandshilo/Pixabay

While climate change is harming nature in a complex variety of ways, one thing is clear.
We cannot restore nature to better health without addressing the climate crisis and we cannot address the climate crisis without restoring nature to better health.

The nature and climate crises are inextricably intertwined, and the good news is, we have the solutions at hand to address them.

What can you do?



Darcie Carruthers

Nature Campaigner