The impact of cats on wildlife is well documented. Our feline friends are excellent killers and they are second only to us when it comes to the widespread decimation of species by a mammal. The situation is not looking good wherever cats are not kept inside, and it is even worse in places like Australia where a large population of feral cats is causing irreversible damage to the local fauna.
In a study published in Wildlife Research, the researchers estimate that an average of 650 million reptiles – like lizards and snakes – are eaten by Australian cats every year. Feral cats kill about 466 million reptiles in their natural habitat and 130 million in urban and suburban areas annually. The remaining 53 million are victims of domestic cats.
"On average each feral cat kills 225 reptiles per year," lead researcher Professor John Woinarski, from Charles Darwin University, told AFP.
"Some cats eat staggering numbers of reptiles. We found many examples of single cats bingeing on lizards, with a record of 40 individual lizards in a single cat stomach."
Cats eat 258 different species of reptiles in Australia and 11 of these are threatened. The team of researchers is particularly worried about the slow-moving large species that live on the ground. Species such as thorny devils and frilled-neck lizard are among the affected critters. A tenth of the world’s reptiles are found in Australia and over 90 percent of local species are unique to the country.
While the toll of cat predation is considerable, the team is unsure of the actual impact on the reptile population. Currently, there is very little data about the number of individuals for many different species of Australian reptiles.
The same team last year estimated the effects of feral cats on bird populations. Roughly 1 million birds are killed by felines in Australia every single day. A third study is currently in preparation and will look at the effect of feral cats on mammals.
The Australian government is taking this threat to conservation seriously. A fund has been put forward to sterilize and cull the feral animals and a cat-free reserve was opened recently. The 70,000-hectare (170,000-acre) region will see several native species reintroduced.