One cat, one year, 110 native animals: lock up your pet, it’s a killing machine


Anton Darius/Unsplash, CC BY

Jaana Dielenberg, The University of Queensland; Brett Murphy, Charles Darwin University; Chris Dickman, University of Sydney; John Woinarski, Charles Darwin University; Leigh-Ann Woolley, Charles Darwin University; Mike Calver, Murdoch University, and Sarah Legge, Australian National University

We know feral cats are an enormous problem for wildlife – across Australia, feral cats collectively kill more than three billion animals per year.

Cats have played a leading role in most of Australia’s 34 mammal extinctions since 1788, and are a big reason populations of at least 123 other threatened native species are dropping.




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But pet cats are wreaking havoc too. Our new analysis compiles the results of 66 different studies on pet cats to gauge the impact of Australia’s pet cat population on the country’s wildlife.

The results are staggering. On average, each roaming pet cat kills 186 reptiles, birds and mammals per year, most of them native to Australia. Collectively, that’s 4,440 to 8,100 animals per square kilometre per year for the area inhabited by pet cats.

More than one-quarter of Aussie households have pet cats.
Jaana Dielenberg, Author provided

If you own a cat and want to protect wildlife, you should keep it inside. In Australia, 1.1 million pet cats are contained 24 hours a day by responsible pet owners. The remaining 2.7 million pet cats – 71% of all pet cats – are able to roam and hunt.

What’s more, your pet cat could be getting out without you knowing. A radio tracking study in Adelaide found that of the 177 cats whom owners believed were inside at night, 69 cats (39%) were sneaking out for nocturnal adventures.

Surely not my cat

Just over one-quarter of Australian households (27%) have pet cats, and about half of cat-owning households have two or more cats.

Many owners believe their animals don’t hunt because they never come across evidence of killed animals.

But studies that used cat video tracking collars or scat analysis (checking what’s in the cat’s poo) have established many pet cats kill animals without bringing them home. On average, pet cats bring home only 15% of their prey.


Wes Mountain/The Conversation, CC BY-ND

Collectively, roaming pet cats kill 390 million animals per year in Australia.

This huge number may lead some pet owners to think the contribution of their own cat wouldn’t make much difference. However, we found even single pet cats have driven declines and complete losses of populations of some native animal species in their area.

Documented cases have included: a feather-tailed glider population in south eastern NSW; a skink population in a Perth suburb; and an olive legless lizard population in Canberra.

Urban cats

On average, an individual feral cat in the bush kills 748 reptiles, birds and mammals a year – four times the toll of a hunting pet cat. But feral cats and pet cats roam over very different areas.

Pet cats are confined to cities and towns, where you’ll find 40 to 70 roaming cats per square kilometre. In the bush there’s only one feral cat for every three to four square kilometres.

So while each pet cat kills fewer animals than a feral cat, their high urban density means the toll is still very high. Per square kilometre per year, pet cats kill 30-50 times more animals than feral cats in the bush.

The impact of roaming pet cats on Australian wildlife.

Most of us want to see native wildlife around towns and cities. But such a vision is being compromised by this extraordinary level of predation, especially as the human population grows and our cities expand.

Many native animals don’t have high reproductive rates so they cannot survive this level of predation. The stakes are especially high for threatened wildlife in urban areas.

Pet cats living near areas with nature also hunt more, reducing the value of places that should be safe havens for wildlife.




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A hidden toll: Australia’s cats kill almost 650 million reptiles a year


The 186 animals each pet cat kills per year on average is made up of 110 native animals (40 reptiles, 38 birds and 32 mammals).

For example, the critically endangered western ringtail possum is found in suburban areas of Mandurah, Bunbury, Busselton and Albany. The possum did not move into these areas – rather, we moved into their habitat.

What can pet owners do?

Keeping your cat securely contained 24 hours a day is the only way to prevent it from killing wildlife.

It’s a myth that a good diet or feeding a cat more meat will prevent hunting: even cats that aren’t hungry will hunt.

A bell on a cat’s collar doesn’t stop hunting, it only makes hunting a little harder.
Wes Mountain/The Conversation, CC BY-ND

Various devices, such as bells on collars, are commercially marketed with the promise of preventing hunting. While some of these items may reduce the rate of successful kills, they don’t prevent hunting altogether.

And they don’t prevent cats from disturbing wildlife. When cats prowl and hunt in an area, wildlife have to spend more time hiding or escaping. This reduces the time spent feeding themselves or their young, or resting.

In Mandurah, WA, the disturbance and hunting of just one pet cat and one stray cat caused the total breeding failure of a colony of more than 100 pairs of fairy terns.

Benefits of a life indoors

Keeping cats indoors protects pet cats from injury, avoids nuisance behaviour and prevents unwanted breeding.

Cats allowed outside often get into fights with other cats, even when they’re not the fighting type (they can be attacked by other cats when running away).

Two cats in Western Australia stopped fairy terns from breeding.
Shutterstock

Roaming cats are also very prone to getting hit by a vehicle. According to the Humane Society of the United States, indoor cats live up to four times longer than those allowed to roam freely.

Indoor cats have lower rates of cat-borne diseases, some of which can infect humans. For example, in humans the cat-borne disease toxoplasmosis can cause illness, miscarriages and birth defects.




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For whom the bell tolls: cats kill more than a million Australian birds every day


But Australia is in a very good position to make change. Compared to many other countries, the Australian public are more aware of how cats threaten native wildlife and more supportive of actions to reduce those impacts.

It won’t be easy. But since more than one million pet cats are already being contained, reducing the impacts from pet cats is clearly possible if we take responsibility for them.The Conversation

Jaana Dielenberg, Science Communication Manager, The University of Queensland; Brett Murphy, Associate Professor / ARC Future Fellow, Charles Darwin University; Chris Dickman, Professor in Terrestrial Ecology, University of Sydney; John Woinarski, Professor (conservation biology), Charles Darwin University; Leigh-Ann Woolley, Adjunct Research Associate, Charles Darwin University; Mike Calver, Associate Professor in Biological Sciences, Murdoch University, and Sarah Legge, Professor, Australian National University

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

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Australia listened to the science on coronavirus. Imagine if we did the same for coal mining



Dan Peled/AAP

Matthew Currell, RMIT University; Adrian Werner, Flinders University; Chris McGrath, The University of Queensland, and Dylan Irvine, Flinders University

Australia’s relative success in stopping the spread of COVID-19 is largely due governments taking expert advice on a complex problem. Unfortunately, the same cannot be said of decisions on projects that threaten the environment – most notably, Adani’s Carmichael coal mine.

Our research published today in Nature Sustainability documents how state and federal governments repeatedly ignored independent scientific advice when assessing and approving the Adani mine’s groundwater plans.

We interrogated scientific evidence available to governments and Adani over almost a decade. Our analysis shows governments failed to compel Adani to fully investigate the environmental risks posed by its water plans, despite concerns raised by scientists.

There is also evidence the government approval decisions were influenced by the political climate and pressure exerted by members of government.

Our findings come as the Morrison government conducts a ten-yearly review of the Environmental Protection and Biodiversity Conservation (EPBC) Act. It is critical these laws – Australia’s most important environmental legislation – are reformed to put rigorous, independent science at the core.

Advice ignored

In mid-2019, the federal and Queensland governments approved groundwater management plans for Adani’s Carmichael coal mine. It granted the company unlimited access to groundwater in central Queensland’s Galilee Basin.

We and other experts warned the mine threatens to damage aquifers, rivers and ecosystems – in particular, the Doongmabulla Springs Complex. This system contains more than 150 wetlands which support rare plant communities found nowhere else on earth.

The springs are of major cultural significance to the Wangan and Jagalingou people.

We analysed the full suite of evidence on the groundwater plans from agencies and scientists with expertise in hydro-geology. The evidence, provided to state and federal environment ministers, spanned almost a decade and included at least six independent scientific reviews.

The evidence highlighted major shortcomings, and gaps in knowledge and data.




Read more:
Unpacking the flaws in Adani’s water management plan


For example in 2013, the federal government’s Independent Expert Scientific Committee on Coal Seam Gas and Large Coal Mining Development (IESC) said key geological characteristics in Adani’s groundwater model were not consistent with available field data.

Expert evidence from court-appointed hydro-geology witnesses in the Land Court of Queensland reiterated this concern and raised new questions over whether the source aquifer for the Doongmabulla Springs had been incorrectly identified.

Subsequent joint reviews by CSIRO and Geoscience Australia in February and June 2019 found Adani had failed to conclusively resolve these issues. The agencies also identified further flaws in Adani’s modelling, including interaction between groundwater and the Carmichael River that was again not consistent with field evidence.

The CSIRO and Geoscience Australia concluded the model was “not suitable to ensure the outcomes sought by the EPBC Act conditions are met”.

Moses 3 Lagoon in the Doongmabulla Springs Complex. Source: Land Services of Coast and Country Inc (2014)

Governments under pressure

The federal government received the reviews from CSIRO and Geoscience Australia in February 2019. It did not publicly release them until then-environment minister Melissa Price announced approval of the groundwater plans on April 8. This was effectively the final federal approval the mine needed to proceed.

Media reports at the time suggested Price had been pressured by members of her government to issue approval before the election. What’s more, her department reportedly pushed the CSIRO to endorse Adani’s plans in just hours, and in the absence of critical information.

Within 48 hours of Adani’s approval being announced, the government called a federal election.




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Morrison government approves next step towards Adani coal mine


The Coalition was returned to power at the election. Federal Labor suffered heavy losses in regional Queensland – a result many claimed was due to their lukewarm support for the Adani mine.

The Queensland Labor government was also required to sign off on the groundwater plans. Following the federal election result, Premier Annastacia Palaszczuk directed that the assessment be completed quickly. The state approved the plans within four weeks.

This was despite being provided a scientific analysis by authors of this article and others, outlining key remaining scientific deficiencies in the groundwater plans.

Once-in-a-decade chance

Our analysis exposes flaws in how evidence informs major government decisions. It also shows why reform of the Environmental Protection and Biodiversity Conservation Act is so urgent.

The laws are currently under review. Many reputable organisations and scholars have proposed ways the legislation can better protect the environment, increase its independence from government and put science at the core.

Independent scientific committees, such as the federal IESC, are commissioned by governments to advise on mining proposals. We suggest such committees be granted greater powers to request specific data and studies from mining companies to address knowledge gaps before advice is issued.

Alternatively – or in addition – a new independent national commission should be established to oversee environmental impact assessments conducted by mining and other development proponents.

This commission should be empowered to interrogate and resolve key scientific uncertainties, free from political interference. Its recommendations to government should take into account a wide range of expert advice and public feedback.

Doongmabulla Springs, a desert oasis scientists say is at risk from the Adani mine.
Flickr

This would not only improve the evidence base for decisions, but may also speed up assessments – ensuring more effective resolution of uncertainties that often lead to protracted conflict and debate about a mine’s impacts.

Such reform is urgently needed. Australia is suffering unprecedented water stress, environmental harm and declining trust in government.

Australian governments listened to the science when it needed to flatten the curve of COVID-19. The same approach is needed if we’re to preserve the places we love and the ecosystems we depend on.




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An Adani spokesperson provided the following response to the claims raised by the authors:

Adani’s Groundwater Dependent Ecosystems Management Plan (GDEMP) was finalised and approved by both the Australian and Queensland governments almost 12 months ago, bringing to an end more than eight years of heavily scrutinised planning and approvals processes.

The approvals were confirmation that the GDEMP complies with all regulatory conditions, following an almost two-year process of rigorous scientific inquiry, review and approvals. This included relevant independent reviews by Australia’s pre-eminent scientific organisations CSIRO and Geoscience Australia.

There are more than 270 conditions within the mine approvals to protect the natural environment and more than 100 of those relate to groundwater.

We’re now getting on with construction of the Carmichael Mine and Rail project, having awarded more than $750 million in contracts to the benefit of regional Queenslanders.

We remain on track to create more than 1,500 direct jobs during the construction and ramp up of our project and some further 6,750 indirect jobs. At a time when our country is facing some of its toughest challenges, we’re determined to deliver on our commitments of jobs and opportunities.The Conversation

Matthew Currell, Associate Professor in Environmental Engineering, School of Engineering, RMIT University; Adrian Werner, Professor of Hydrogeology, Flinders University; Chris McGrath, Associate Professor in Environmental and Planning Regulation and Policy, The University of Queensland, and Dylan Irvine, Senior lecturer in hydrogeology, Flinders University

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