Cats allowed outdoors kill an average of between three and four animals a month. Researchers made the finding when they surveyed more than 900 cat owners in six countries around the globe, including the United States, the United Kingdom, and Australia.
Many people who let their cats wander outside brush away the wildlife deaths by saying that feline hunting is nature’s way of keeping our fragile ecology in balance. But the researchers, reporting in the journal Animal Conservation, point out that pet cats permitted to roam put at risk those very species of animals already endangered because they live in close proximity to people and therefore have had their habitats encroached on by human development. Among the endangered species: possum, rabbits, and various rodents. On small islands, the researchers point out, the ability of cats to roam free has resulted in at least 33 animal extinctions.
Pet cats don’t kill as many animals as their carnivorous counterparts who live full time in the wild, as they are fed complete meals at home and don’t need to capture prey to eat. But the high density of cats in human neighborhoods amplifies the effects of their hunting expeditions, the researchers say. They proved the point when they tracked the movements of the hundreds of cats on three continents with GPS loggers. Most cats didn’t wander any further than about 325 feet from their homes. This was true whether the cats lived in urban areas, suburbs, or more rural areas. But the devastation they caused to species living close to people or “along the urban fringe” was much greater than that of wild animals who fed in the same areas. It makes sense in light of the fact that where people live, cats are more concentrated than other carnivores.
There are more than enough reasons to keep your pet cat indoors for his own sake. That way, he will be safe from cars, larger predators, and barbed fences and other harmful objects. But because cat populations are unnaturally large wherever people live, these pets can do more than their share of harm to other animals living nearby and should be kept in the house. That is what will help preserve ecological balance.