[ad_1]
We know that wild cats are a huge problem for wildlife: across Australia, wild cats collectively kill over three billion animals per year.
Cats have played a leading role in most of Australia’s 34 mammal extinctions since 1788, and are one of the main reasons why populations of at least 123 threatened native species are declining.
But domestic cats are also wreaking havoc. Our new analysis compiles the results of 66 different studies in domestic cats to measure the impact of Australia’s domestic cat population on the country’s wildlife.
The results are astonishing. On average, each 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 kilometer per year for the area inhabited by domestic cats.
READ MORE:
Keeping cats indoors at night is best way to help wildlife, study finds
* “Screaming kids” accused of ruining neighborhood parks
* Cats kill over a million birds a day in Australia
If you have a cat and want to protect wildlife, you should keep it indoors. In Australia, 1.1 million domestic cats are contained 24 hours a day by responsible owners. The remaining 2.7 million domestic cats, 71 percent of all domestic cats, can roam and hunt.
Also, your pet cat could be dating without you knowing. A radio tracking study in Adelaide found that of the 177 cats the owners believed were inside at night, 69 cats (39 percent) sneaked away for nighttime adventures.
Surely not my cat
Just over a quarter of Australian households (27 percent) have domestic cats, and approximately half of cat-owning households have two or more cats.
Many owners believe that their animals do not hunt because they never find evidence of dead animals.
But studies using cat video tracking collars or feces analysis (checking what’s in cat poop) have established that many cats kill animals without bringing them home. On average, domestic cats bring home only 15 percent of their prey.
Collectively, roaming domestic cats kill 390 million animals per year in Australia.
This large number may lead some pet owners to think that their own cat’s contribution would not make much difference. However, we found that even single cats have caused complete declines and losses in the populations of some native animal species in their area.
Documented cases have included: a population of feather-tailed gliders in southeastern New South Wales; a skink population in a Perth suburb; and a population of lizards without olive legs in Canberra.
Urban cats
On average, an individual wild cat in the bush kills 748 reptiles, birds, and mammals a year, four times more than a hunting cat. But feral cats and domestic cats roam very different areas.
Domestic cats are limited to cities and towns, where you will find between 40 and 70 itinerant cats per square kilometer. In the bush there is only one wild cat for every three or four square kilometers.
So although each cat kills fewer animals than a wild cat, its high urban density means the number is still very high. Per square kilometer per year, domestic cats kill 30-50 times more animals than wild cats in the bush.
Most of us want to see native wildlife around towns and cities. But that vision is compromised by this extraordinary level of predation, especially as the human population grows and our cities expand.
Many native animals do not have high reproductive rates, so they cannot survive this level of predation. The stakes are high for threatened wildlife in urban areas.
Domestic cats that live near wilderness areas also hunt more, reducing the value of places that should be safe havens for wildlife.
The 186 animals that each pet cat kills per year on average are made up of 110 native animals (40 reptiles, 38 birds and 32 mammals).
For example, the critically endangered western possum is found in suburban areas of Mandurah, Bunbury, Busselton, and Albany. The opossum did not move to these areas, but we moved to its habitat.
What can pet owners do?
Keeping your cat safely contained 24 hours a day is the only way to prevent it from killing wildlife.
It is a myth that a good diet or feeding a cat with more meat will prevent hunting: even cats that are not hungry will hunt.
Various devices, such as bells on necklaces, are marketed with the promise of preventing hunting. While some of these elements can reduce the rate of successful deaths, they do not completely prevent hunting.
And they don’t prevent cats from disturbing wildlife. When cats prowl and hunt in an area, wildlife has 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 total reproductive failure of a colony of more than 100 pairs of terns.
Benefits of indoor living
Keeping cats indoors protects domestic cats from injury, prevents nuisance behavior, and prevents unwanted breeding.
Cats allowed outside often fight with other cats, even when they are not the fight type (they can be attacked by other cats when they run away).
Itinerant cats are also very likely to be hit by a vehicle. According to the Humane Society of the United States, indoor cats live up to four times longer than those that can roam freely.
Indoor cats have lower rates of cat-borne diseases, some of which can infect humans. For example, in humans, cat-borne disease toxoplasmosis can cause illness, miscarriage, and birth defects.
But Australia is in a very good position to make changes. Compared to many other countries, the Australian public is more aware of how cats threaten native wildlife and more supportive of actions to reduce those impacts.
It will not be easy But since more than a million domestic cats are already contained, reducing the impacts of domestic cats is clearly possible if we take responsibility for them.
Contributors to this story include:
– Brett Murphy, John Woinarski, Leigh-ann Woolley are professors at Charles Darwin University.
– Chris Dickman is professor of terrestrial ecology at the University of Sydney.
– Jaana Dielenberg is Manager of Scientific Communication at the University of Queensland.
– Sarah Legge is a professor at the Australian National University.
– Mike Calver is professor of biological sciences at Murdoch University.
This article was originally published in The Conversation. Read the original article here.
