Spring 2005

Of Cats & Birds

Think twice about letting your kitty outdoors. Native birds are easy prey for Felis catus.

By Craig Vetter

ALL MY CHICAGO CATS HAVE HOBOED IN THROUGH an open door, looked around, found everything to their liking, and made themselves at home. I’ve had three of these wander-ins over the years, and living with them has somehow left me with the feeling that, although I may be at the top of the food chain nominally, I’m there mostly so that stray cats can eat well and sleep wherever in my house they like, including on my face. Or as one anonymous wag put it, “There are many intelligent species in the universe. They are all owned by cats.”

I’ve always let my cats come and go as they wanted, guided by the feeling that they knew what they were doing in the outdoors. And, in the case of the lithe, pure-black street girl who sauntered in some years ago, it was the relentless and blood-curdling yowl she released when I wouldn’t be her doorman that convinced me this was a good idea. There didn’t seem to be any particular harm in letting Lulu, the Queen of the Nile, wander — until the day she showed up with a small, quivering bird in her teeth. She played soccer with it until I took it from her, felt it die in my hands, and buried it.

I didn’t know it then, but it turns out that little house sparrow was one of millions of birds that are killed by domestic and feral cats every year; a toll, bird advocates speculate, that may be endangering some migratory and resident bird populations.

No one knows for sure the predation rate of cat upon bird, because counting felines is even more difficult than bathing them. Felis catus, domesticated felines, descended from European wildcats — a distinct species from the wildcats of Africa and Asia. Introduced into North America with the European colonists, they have since become the most popular pet in America. Wildly varying estimates suggest there may be as many as 100 million in the country. Fifty to sixty percent roam freely outside. In Chicago, based on figures presented at an American Veterinary Medical Association forum, the cat census is around 700,000 owned cats and 500,000 feral. (There are no guesses as to how many of them are on the voter rolls.)

One of the most often cited studies on bird kills by cats was done at the University of Wisconsin-Madison by John Coleman and Stanley Temple. A five-year study ending in 1994, it focused on rural cats that lived in a house or barn and were free to roam. The researchers found that these cats killed an average of 23 birds a year, mostly ground-feeding species such as meadowlarks, robins, and sparrows.

“Recent research,” the authors wrote, “suggests that rural free-ranging cats in Wisconsin may be killing between 8 and 217 million birds. The most reasonable estimates indicate that 39 million birds are killed in the state each year.” This sizeable range makes me think that when Thoreau suggested it wasn’t worth it to go ‘round the world to count the cats in Zanzibar, he hadn’t even come to the hard part yet — trying to count the birds the cats in Zanzibar kill.

A study of urban cats in Wichita, Kansas, in 2000 by Carol Fiore and Karen Sullivan found city felines averaging around four birds per year. This number is low, since the researchers only counted kills they could physically verify, but it supports other studies that found urban cats killing fewer birds than their rural counterparts.

“There are no statistics on death rates in the Chicago region, nothing quantitative, but the anecdotal reports are huge,” says Donnie Dann, head of the Bird Conservation Network. “Cats are constantly showing their owners what good hunters they are.” Owners have reported their pets bringing them the common birds people feed in their yards, along with other ground-nesting and ground-feeding species.

“When something like a cat is newly introduced into their ecosystem, it has an incredible advantage in picking off these unsuspecting birds,” Dann says. “There are even reports of cats snatching hummingbirds out of the air.”

“When you factor in decreasing habitat with the hundreds of millions of cat kills, the toll on bird populations is very serious,” says Linda Winter, director of Cats Indoors!, a program begun by the American Bird Conservancy (ABC) in 1997. For some species, a handful of birds lost can make the difference between a local population’s success and failure. The Wichita study found that cats in that city killed mostly house sparrows, house wrens, and immature starlings — birds that thrive in disrupted urban landscapes. This stands to reason, since domestic cats usually dwell near houses. But the study also noted kills of more sensitive species, such as dickcissels, yellow-billed cuckoos, Lincoln’s sparrows, and Swainson’s thrushes. Even if Chicago’s urban and suburban cats don’t roam as much as the rural cats in Temple’s study (males had 12-acre territories while females covered only 3 acres), they are within easy striking distance of our grassland and woodland preserves. “We know thatcats hunt the forest preserves,” says Dann.

Migration brings hundreds of bird species flapping through their favorite travel corridors and resting places, often close to human habitation. Don’t reveal these to your cat. “Before they began the demolition at Soldier Field,” says Dann, “there were cats who waited along the lake there for migrants like Connecticut warblers.” Outdoor cats can also make a killing along rivers, and in yards that have birdfeeders and natural landscaping.

“It doesn’t help to bell a cat because they learn to hunt silently,” Dann says. “It doesn’t help that they are well fed because it’s in their nature to hunt. You can’t blame the cat.” And cats kill other critters as well. According to ABC, 60 to 70 percent of a cat’s kills are small mammals — not just housemice and rats but chipmunks and many other native species.

“The great majority of our readers agree completely that cats should stay indoors,” says Susan Logan, editor of Cat Fancy magazine. “For their own health and safety as well as that of other wildlife.” Logan has two cats and says that she suffered some days and nights of yowling as her adult felines adapted to life indoors. “I just turned up the TV to drown them out,” she says, “and they eventually got used to life in the house.”

I’ve never had a TV with volume enough to out-shout Lulu, but I think now I maybe should have tried to convert her to life indoors. After about six years she wandered off the way she wandered in. I don’t know what happened to her or the birds she might have ambushed. In retrospect, it’s hard to make a case for letting the cat out, because cats will be cats. Or, as cat portraitist Missy Dizick put it, “Some people say that cats are sneaky, evil, and cruel. True, and they have many other fine qualities as well.”

Related Articles

Pets, Feral Domestic Animals Prey Heavily On Wildlife (Wisconson DNR Press Release)

Attracting Birds to Your Feeder and Your Yard (CW, Winter 2001)

On the Prowl (Wisconsin Natural Resources magazine)

Cats and Wildlife: A Conservation Dilemma (Coleman, Temple, and Craven)