There have been two serial killers in my life. The first was a former student. A couple of years after he graduated from my university, he murdered his father, his mother, his younger brother, and the family dog. After he was arrested, the local television station sent a reporter to interview me because I had been his academic advisor. When the reporter asked me what he was like, I stupidly looked at the camera and mumbled the classic cliché:
"Well, he was quiet and kind of shy, but he seemed like a nice guy."
The same could be said of the other killer in my life, my cat Tilley. She spends part her days outdoors, and like most cats, she is a recreational hunter. I am usually successful in suppressing the guilt that comes with having a serial killer for a companion animal, but a recent report in the journal Nature Communications has caused me to rethink the ethics of keeping predators as pets.
Based on existing data, the researchers concluded that the havoc wreaked by cats on native animal populations has been vastly underestimated. They calculated that in the US, cats kill between 8bn and 24bn small, feathered, and furry creatures a year, and are the largest human-related source of mortality among birds and mammals. While most of this carnage is caused by free-ranging stray cats, it is nearly certain that pet cats are responsible for at least 1-2bn of these deaths.
Are tabbies in the UK as deadly as their American cousins? Probably. A 2003 study of cats living in 600 British households found that over a five-month period, the cats brought home the carcasses of over 14,000 small animals. With 10m cats living in British homes, the numbers add up.
The moral burden of cat ownership can fall particularly hard on animal protectionists. Take, for example, a recent conversation I had with a young woman I will call Jessie. She believes killing animals because they taste good is immoral; she is a vegan and consumes no meat or dairy products. She does, however, live with four pet cats. She tried feeding them vegetarian cat food, but, unsurprisingly, her pets hated it.
She reverted to feeding them canned food and the moral burden of their diet weighs heavily on her. It should. At two ounces of meat a day, her cats will collectively eat 3,240lb of meat over their life spans.
Jessie could, of course, reduce the moral costs of feline companionship by keeping her cats indoors. While her pets would still dine on canned flesh, forcing them to live inside would reduce the damage to her neighborhood wildlife. The problem, she told me, is that her cats love the outdoors. She gets depressed when she sees them sitting in the window, wistfully looking out at the birds flitting by.
I agree with her. That's why, like most cat lovers, I don't force Tilly to spend her life in the big cage I call my house. Indeed, one of the arguments made against zoos and factory farms is that they do not allow animals to exhibit their natural behaviors. The animal rights philosopher Bernard Rollin, for example, argues we have an obligation to respect an animal's telos, that is, its essence or purpose. As Rollin puts it, "fish gotta swim, birds gotta fly". I suppose, by this logic, "cats gotta kill."
Jessie is facing a no-win situation. Her commitment to animal liberation has caused her to change the clothes she wears and the food she eats … yet, she's devoted to her four stone-cold killers. Her choice: learn to live with inconsistency or say goodbye to the kitties.
The existence of millions of feral cats in Europe and the US pose a similar set of bad choices. Unowned cats are, by far, the largest cause of the decimation of birds and small mammal populations. An obvious solution would be to simply kill feral cats on sight. But would reducing the number of free-ranging cats actually increase native bird and mammal populations?
A natural experiment suggests the answer is yes. Two ecologists, Kevin Crooks and Michael Soulé, studied the interactions between cats and their predators, coyotes, on bird populations in the urban ravines of southern California. Having a coyote in the neighborhood reduced the number of cats. (Indeed, 25% of their radio-collared cats were eaten by coyotes.) More importantly, having a cat-killing predator around the neighborhood significantly increased the number and diversity of birds flying around urban backyards.
Putting a bounty of feral cats would, of course, be unacceptable to the millions of us who are cat lovers. An alternative cat reduction strategy has emerged in recent years – "trap-neuter-return" programs, in which free-ranging cats are captured, neutered, and set free. Often these animals live in groups under loose human supervision. As you might expect, bird enthusiasts are not happy with the proliferation of these "cat colonies", and indeed, a recent survey found that cat colony caretakers and bird conservation professionals live in different moral worlds. For example, while 90% of birders agreed that feral cats contribute to the decline of native birds, only 20% of cat-advocates agreed.
The birders, it seems, are right. "Trap-neuter-return" programs may eventually reduce the numbers of free-ranging cats, but they will probably take decades to have an appreciable impact. In the meantime, billions of wild birds and mammals will die and some species will become extinct.
Jesse was faced with the prospects of either getting rid of her beloved pets or living in violation of her convictions. The existence of millions of feral killing machines in our alleyways and backyards poses an equally unpalatable dilemma.