There is a scourge out there that’s absolutely devastating wildlife and for many in leafy suburbia it’s right underneath their noses – the common house cat. Most people have heard stories of islands left entirely bereft of wildlife due to cats, and homeowners can attest to frogs, birds, lizards and mice being brought into the house as offerings, but a new study has shown that these “offerings” are only the tip of a shocking iceberg.
Thirteen scholars from Universities as far afield as North Carolina and New Zealand fitted a total of 925 house cats across six countries with unobtrusive GPS devices, tracking their range and their pray kills and what they found was worse than expected.
“We found that house cats have a two- to 10-times larger impact on wildlife than wild predators; a striking effect,” said Roland Kays, lead study author and zoologist at the North Carolina Museum of Natural Sciences, adding, “Since they are fed cat food, pets kill fewer prey per day than wild predators, but their home ranges were so small that this effect on local prey ends up getting really concentrated. Add to this the unnaturally high density of pet cats in some areas, and the risk to bird and small mammal population gets even worse.”
The study found that house cats on average roamed just 100 metres from the house they lived in and killed anywhere between 14.2 to 38.9 prey per 100 acres, per year. That averages out to about 3.5 prey each month per cat. The problem though is not with the cat’s nature, but rather with the fact that humans have bred them well beyond a level they would exist in naturally. There are roughly 600-million cats worldwide, and when this is placed alongside the kill ratio above one can see just how much impact these animals are having on the environment.
The study further indicated that a number of animals had been brought the brink of extinction by the common house cat including Brushtail possums in South Australia, and a number of rodents and rabbits in North America
Researchers have offered a relatively simple solution to the problem though, as they say simply keeping cats indoors, particularly at night, could prevent the impact on wildlife.
“Humans find joy in biodiversity, but we have, by letting cats go outdoors, unwittingly engineered a world in which such joys are ever harder to experience.”