Australia is the only continent besides Antarctica to have never had any felines until the arrival of Europeans (specifically, those who came during the 17th through 19th centuries), and yet now it is completely overrun with them. An analysis conducted by the Australian Government's National Environmental Science Programme involving 40 top Australian scientists and over 90 separate studies has revealed feral cats cover a staggering 99.8 percent of the continent, and 80 percent of the area of its islands. A grim prospect indeed for the many species of unique mammals and birds living there that are regularly destroyed by feral cats. The study was published last month online in the journal Biological Conservation.
Cats make great pets. They're cute, furry, relatively easy to take care of, and make great alarm clocks— albeit ones that sock you in the face because they're hungry. They also, however, are some of the most efficient killers on planet Earth. Good ol' Sneakers might curl up on your lap like a dear, but if you let him outside, he's guaranteed to be a cold-blooded murderer. On islands particularly, where feral cats are invasive, many species of birds have fallen victim to the claw. In Australia, now literally crawling with felines, cats are responsible for the extinction of 20 species of native mammals. And they don't appear to be going anywhere.
"Australia's total feral cat population fluctuates between 2.1 million when times are lean, up to 6.3 million when widespread rain results in plenty of available prey," said ecologist and co-author of the analysis Sarah Legge, of the University of Queensland, in a press release. This is actually lower than previous estimates, as the authors note. Still, it's a pretty staggering number, and the fluctuation is equally interesting, as seen in the following map (the darker areas show higher cat-density following rainfalls):
And the researchers found that cats were just as prevalent inside National Parks as outside them, directly undermining conservation efforts. They also, perhaps not surprisingly, found the furry raiders to be up to 30 times as dense in heavily urbanized areas as elsewhere—probably due to the availability of easily accessible food. Unfortunately, these city hubs create many of the feral cats that flee to the bushlands where they can kill freely.
"Feral cats have been devastating for our wildlife," said Gregory Andrews, the Australian government's Threatened Species Commissioner, in a public statement. "Australia is the only continent on Earth other than Antarctica where the animals evolved without cats, which is a reason our wildlife is so vulnerable to them. This reinforces the need to cull feral cats humanely and effectively," he said.
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