In a recent listing of animal species that I consider beneficial to humans, I gave domestic cats a high ranking. Of course, people who dislike cats don't agree with that position. But even some cat-fanciers think domestic cats are beneficial only if they remain indoors. They assert that free-roaming house cats are a scourge to small wildlife.
First some facts. Numerous scientific articles have documented that domestic cats have a measurable impact on native wildlife. Outdoor cats kill staggering numbers of songbirds, lizards, and small mammals every year. Therefore, anti-outdoor-cat activists take a firm position: domestic cats turned out for even part of the day cause great environmental harm by relentlessly killing small wild animals.
But the issue is not black-and-white like a jellicle cat. It consists of many shades of gray. Justifications for letting typical house cats have free rein out-of-doors also abound. Outdoor cat advocates avow that outside cats are not an environmental problem. Following are some comments I have received in support of letting cats have their way outside (as they are accustomed to doing inside).
One individual said, “I am puzzled by the concern some people have for native wildlife that suffers because house cats go outside. What exactly is the problem? No animal has ever gone extinct because of cats. In fact, I have never heard of any species of wild animal even being eliminated from a region because of `killer' cats. Lizards still seem to be around my house, along with chipmunks and small birds. I ask again, what is the problem people have with outdoor cats?”
Another person wrote, “Cars kill far more native wildlife than my cats. One, named Kat, kills a few mice, bunnies, and lizards a year--how many of the same are killed by automobiles? I assure you more population damage is done by cars (thus, by people) than by Kat. Also, does the fact that cats are not native exclude them from being a part of the legitimate food chain?
“My other cat, Spencer, is not even part of the equation. The only `kill' he has ever brought home was a dried-up lizard that had been run over by a car days earlier. I did turn on the deck light recently to find Spencer and a possum eating out of the same food bowl. Spencer looked a little confused but kept eating. So did the possum. I bet that possum will kill a lot more wildlife over the year than Spencer and Kat put together. So why shouldn't my cats go outside?”
One interesting environmental perspective is that “house cats that go outdoors and kill small animals need to be viewed from the position of whether the environmental impact they are having is any greater than native predators would extract if they were around. Would not all these small animals have to deal with bobcats and coyotes and foxes in the real world of native animals? Maybe house cats are simply filling a role that we eliminated by our removal of natural predators. Maybe house cats are actually returning the outdoors closer to a natural system than what we have now without native predators.”
Folks who enjoy backyard bird-watching should probably keep their cats inside, as some cats would take their toll. But, as noted above, cars kill far more animals than do outdoor cats. In fact, cat owners in some neighborhoods should be less worried about their backyard wildlife than about finding their cat dead in the street that runs in front of their house.
Whether people should be required or at least encouraged to keep their cats indoors will never be resolved to everyone's satisfaction. Thus it will remain a divisive issue that can lead to, shall we say, spirited discussions when people with differing views meet. If you want to test the truth of that assertion, at the next cocktail party you attend, just state your position on outdoor cats – then step back.
Whit Gibbons is an ecologist and environmental educator with the University of Georgia's Savannah River Ecology Laboratory. Send environmental questions to firstname.lastname@example.org.