Australia is an extinction world leader, and invasive species we introduced are largely to blame. Let’s be the generation that ends invasive species-led extinctions in Australia.
Australia is truly spoilt when it comes to nature. We are a global biodiversity hotspot and one of just 17 ‘megadiverse’ countries on the planet.
But our unique diversity, shaped over millions of years in isolation, is vulnerable to outside forces. Sadly, Australia is a world leader in species extinction and declines, largely due to invasive species.
We hold the unenviable record for most mammal extinctions, and come 4th for total extinctions globally. At least 33 (probably 34) native mammal species have been lost to extinction since colonisation, a toll blamed mainly on introduced cats and foxes.
Since 2009, invasive species have been the leading cause behind 4 of Australia’s 5 animal extinctions.
Invasives: Australia’s leading cause of animal extinction
In 2019, scientists from the Threatened Species Recovery Hub – a consortium of universities and other bodies investigating endangerment and extinction – undertook a comprehensive analysis of Australia’s extinction record. Shockingly, they found invasive species were the main cause of most Australian animal extinctions – 45 of 100 extinctions, while habitat loss accounted for 36. Hunting was the main cause of 6 extinctions, livestock grazing 4, modified hydrology 4, other ecosystem modifications 3. Climate change, fire and pollution had each caused one extinction.
With this new information, it’s critical we take control of Australia’s invasive species problem – before it’s too late.
Prey naivety: why Australian wildlife is so vulnerable to invasive species
Our wildlife is admired the world over for its uniqueness, but that also makes it unusually vulnerable to species that come from elsewhere.
The concept of prey naivety explains why so many Australian marsupials and rodents succumb to foxes and cats. These animals are adapted to native predators but the new carnivores operate differently. Cats have an ambush mode of hunting unlike that of native predators, leaving smaller animals un-adapted to their attacks.
Prey naivety applies to most of Australia’s animal extinctions. Frogs and native rats were immunologically naive towards introduced pathogens. Birds on Lord Howe Island were naive about the black rats that came ashore from a shipwreck, and Christmas Island animals were naive about invasive wolf snakes.
Australia has lost about 100 native plants and animals to extinction since colonisation, most of which were mainly due to invasive species. An estimated 27 of those extinctions occurred since the 1960s.
Christmas Island pipistrelle
Yallara (lesser bilby)
Mountain mist frog
Sharp-snouted day frog
Right now, just one exotic pathogen – Phytophthora cinnamomi – threatens hundreds of plant species found nowhere else in the world. Foxes and cats threaten the existence of many more Australian mammals (cats alone kill an estimated 2 billion animals in Australia every year). And goats, pigs, camels, deer and others are degrading vast areas of threatened species’ habitat – making it harder for them to survive against other threats.
With about 100 plant and animal species facing a high risk of imminent extinction, Australia is on the brink of an extinction catastrophe. Invasive species are a significant threat to almost three-quarters of these predicted extinctions.
Without urgent action to manage environmental invaders, we will lose even more of the incredible plants, animals and ecosystems that make Australia special.
Almost 2,000 native plants and animals are currently listed as threatened with extinction.
A recent assessment found about 100 of Australia’s species, including the plains wanderer and the native guava, currently have a ‘high’ or greater-than-50% risk of extinction within 10–20 years. Invasive species represent a significant threat to nearly three-quarters of those high risk species.
Northern corroboree frog
Mountain pygmy possum
The choice is clear
Our alarming extinction rate will continue unless there’s urgent investment and action on invasive species.
Together we can create an Australia where koalas, quolls, frogs, fish and all the plants and animals that make Australia unique can thrive – far into the future.
To get there, we need to urgently and drastically reduce existing populations of invasive species as well as prevent new ones from taking hold.
That means working together to raise awareness of what’s at stake and pushing our leaders to do more.
Right now we have a critical window of opportunity to better protect Australia’s native plants and animals from deadly invasive species.
The Australian Government is currently reforming our key environmental legislation – the Environment Protection and Biodiversity Conservation (EPBC) Act 1999.
If enough of us speak out, we can ensure they strengthen Australia’s threat abatement system and provide adequate funding for better invasive species management through the new and improved EPBC Act.
Send a letter to our Environment Minister now urging them to strengthen the laws and systems meant to prevent extinctions – before it’s too late.
Once an animal is extinct it’s gone forever. Let’s be the generation that ends invasive species-led extinctions in Australia.