Our beloved feline companions may be picky eaters, but when it comes to their diet, they prove to be indiscriminate hunters. A recent global study examining the prey of free-roaming domestic cats, both pets and feral, reveals that these agile felines are extreme generalists, consuming a wide range of species.
While cat owners, especially those in Australia, are aware of the threat their pets pose to wildlife, the actual numbers are staggering. In Australia alone, an estimated 1.5 billion native animals fall victim to domestic cat predation annually. The global impact of their voracious appetite is even more significant than previously understood.
According to the analysis led by ecologist Christopher Lepczyk from Auburn University, domestic cats (Felis catus) are cunning predators that target over 2,000 different species worldwide. Out of these, 347 are classified as species of conservation concern, with some already marked as extinct.
While the threat of free-roaming cats leading to animal extinctions is well-documented in places like Australia, their predatory habits in other regions are less known.
Lepczyk and his team meticulously compiled records of cat predation from various sources, including books, scientific papers, and reports spanning back to the early 1900s. Birds (981 species), reptiles (463 species), and mammals (431 species) comprised the majority of the 2,084 species targeted by cats. The feline menu even included unexpected entries like emus, green sea turtles, cattle, and bullfrogs.
“We don’t really know of any other mammal that eats this many different species,” Lepczyk explained. “It’s almost like an indiscriminate eater; they’re eating whatever’s available.”
The evidence, based on documented instances of cat predation without anecdotal reports, revealed that cats consume almost 9 percent of all known bird species and over 6 percent of known mammals.
Out of the 347 species of conservation concern targeted by cats, a quarter were found on islands, including the near-threatened western quoll in Western Australia and the critically endangered Newell’s shearwater in Hawaii.
Despite the alarming figures, the researchers believe the analysis likely underestimates the true extent of cat predation. Challenges in identifying prey species and categorizing many as ‘unknown,’ coupled with the opportunistic hunting nature of cats, contribute to this underestimation.
Cats, being opportunistic predators, often hunt without consuming their catch, further complicating the estimation of their true impact. Additionally, the difficulty in identifying insect remains in cats’ stomachs and scats, along with the limited knowledge of a small fraction of insect species, adds complexity to the assessment.
Most cat diet studies have been conducted in Australia and North America, leaving biodiversity hotspots in Asia, Africa, and South America largely unexplored. The researchers emphasize that critical locations for evaluating cat predation and scavenging are likely missing due to the lack of sampling in many biodiverse regions.
Efforts to control invasive cat populations over large areas have faced challenges, prompting researchers to explore new strategies. Meanwhile, cat owners are encouraged to keep their pets indoors for the safety of both the cats and the surrounding wildlife.
The study detailing these findings has been published in Nature Communications.
