'Cats Eat a Lot More Than We Thought'

Cats are far from finicky eaters when it comes to wildlife, researchers say. According to a study published in Nature, cats are "indiscriminate predators and eat essentially any type of animal that they can capture at some life stage or can scavenge." Researchers say cats worldwide—feral cats as well as domestic cats allowed to roam outside—are eating more than 2,000 species, including many endangered creatures, the Guardian reports. The researchers, who call the estimate a conservative one, say cats have consumed 981 species of bird, 463 species of reptiles, and 431 species of mammal, as well as scores of species of amphibians and insects. They say they got their information from more than 500 publications with records of species eaten by cats.

"Cats eat a lot more than we thought," says study co-author Christopher Lepczyk, an ecologist at Auburn University and one of the study's authors. "That's meaningful." Some surprising species eaten by cats include camels and green sea turtles, though the camels were probably scavenged and the turtles were hatchlings, the New York Times reports. Almost 17% of the species were listed as near threatened or of higher concern, according to researchers, who describe cats as one of the "most problematic invasive species in the world." They note that cats have been linked to around 26% of extinctions of bird, mammal, and reptile species, especially on islands.

The researchers say much of their data came from places like Australia and New Zealand, where the impact of cats has been extensively studied. There was relatively little data from biodiversity hotspots in Africa, Asia, and South America, researchers said, but animals in those places may be less vulnerable to cat predation because they co-evolved with native feline species. The report doesn't say how the problem could be addressed. Lepczyk tells NPR its purpose was to "help provide that information to ecologists, to practitioners, and to policymakers." He says he keeps his own cats indoors—and studies show indoor cats live longer, healthier lives. (More cats stories.)