Want to Stop Your Cat From Killing Birds? Dress It Up Like a Clown

A biologist finds that putting a Bozo collar on felines helps save wildlife.
Feb 27, 2015· 3 MIN READ
Richard Conniff is the author of House of Lost Worlds: Dinosaurs, Dynasties, and the Story of Life on Earth and other books.

Stare deeply into a cat’s eyes, and you’ll see the unavoidable truth: It is a sleek, stealthy killing machine. In the United States, outdoor cats kill billions of birds, amphibians, and small mammals every year. Despite a widespread campaign by environmentalists to persuade people to keep their little killers indoors, many cat owners refuse to do so. A new product from a company called Birdsbesafe won’t entirely fix that problem, but it will help, and two scientific studies suggest that it works. It’s the sort of collar a clown would wear, with brightly colored frill sticking out all around, making the wearer much easier to see and avoid.

Susan Willson, a Birdsbesafe customer, was hunting around on the Internet when she found the collar. She knew how deadly cats can be. It’s not just that she’s a conservation biologist specializing in birds at St. Lawrence University in Canton, New York. She’s also the owner of two outdoor cats, and one of them, “the Gorilla,” is especially adept at killing birds. “Obviously, the best thing to do is to keep your cat inside,” Willson said. But when she tried bringing the Gorilla inside, it touched off what she describes as “a peeing war” with her three indoor cats.

“At that point, we couldn’t keep him in,” she said, but euthanizing him was a “pretty unpalatable” option. Instead, she ordered the colorful collar, which sells for $10 to $15. It worked—or seemed to work—so well on her cat that Willson set out to conduct a proper scientific study testing whether the collars were as effective as they seemed to be.

Willson focused the study on “the nastiest of the cats out there,” the serial killers of the domestic feline world, rejecting the study cats that only occasionally or never brought birds back to the house. She asked cat owners to put the victims in plastic bags and store them in their freezers. At the end of each season, Willson collected and identified all the victims—cedar waxwings, purple finches, magnolia warblers, and other birds, as well as small mammals like shrews and even two flying squirrels.

The results, recently published in the journal Global Ecology and Conservation, were impressive. In the spring,cats with collars killed about a twentieth the number of birds uncollared cats killed, and in the fall, about a third as many. “The Birdsbesafe collar is highly effective at reducing bird deaths,” the study concluded. Did the cats feel it offended their dignity to be dressed up like Bozo the Clown? Apparently not. Most cats adjusted well to the collar—beneath the frill it’s just a conventional breakaway cat collar—with less than a quarter continually trying to remove it or showing distress, according to their owners.

Another study, in Australia, also found that the collar reduced the number of dead birds brought home by cats but only by about half. The collar also failed to protect small mammals, which generally lack good color vision. (That might sound like a benefit for cat owners who don’t have much use for mice or other rodents. But in Australia, introduced cats and foxes have already driven 10 percent of the continent’s native mammal species to extinction.)

Birdsbesafe founder Nancy Brennan devised the collar six years ago, after her fiancé’s cat brought home a dead ruffed grouse. Over the years, she’s tried a variety of patterns and colors and says she now has a pretty good sense of what works and what doesn’t. She also readily acknowledges the one method that works best: “If everybody in the world would keep all their cats indoors, I’d be thrilled,” said Brennan.

Staying indoors is better not just for birds but for the safety of the cats. Car strikes are one of the leading causes of death for outdoor cats. It’s also better for human health because outdoor cats are active carriers of toxoplasmosis and other debilitating diseases. (Check out this site for more information about these diseases and for methods of allowing cats to be outdoors while also keeping them safely contained.) But Brennan said many of her customers feel that their cats are happier outside or simply wouldn’t adjust to indoor life. “I think of Birdsbesafe as a partial solution to a complex problem.”

Asked to comment about the collar, Grant Sizemore, who helps lead the “Cats Indoors” campaign for the American Bird Conservancy, replied that the conservancy “is always in favor of reducing the impacts of outdoor cats on birds and other wildlife.” But if the collars make cat owners feel comfortable letting their cats outside when they would otherwise keep them in, the collars could result in more predation by cats. He also pointed out that cats can have indirect impacts on birds just by prowling around outside, making birds feed their offspring less and increase their alarm calls.

Here’s the bottom line for owners of outdoor cats: The collar offers a way to do a little less environmental damage and feel less guilty as you transition, with this cat or the next one, to an indoor life. Getting to that point is the best thing you can do for wildlife, your cat, and your health.

Geoffrey Giller contributed reporting for this column.