Join the movement to protect cats

Sign up for our mailing list and learn how you can help us win the battle against unnecessary killing of cats. Sign up now »

These Stats are for the Birds

The rather tired—very bogus—debate about cats outdoors re-emerged on September 30, 2010, this time in the "Home" section of the Washington Post. As usual, bird advocates trotted out some spectacular statistics in trying to make the argument that outdoor cats have any significant impact on bird populations. Let’s set the record straight.

People are the most significant contributor to bird death.

Let’s be unequivocally clear—the number one threat to birds is people. Human-led activities kill hundreds of millions of birds per year. Cats barely even rank when compared to the very real problems of habitat loss, urbanization, pollution and environmental degradation. Researchers estimate that in the U.S. alone, nearly 100 million birds die from collisions with windows and buildings every year. Eighty million birds die from collisions with automobiles. Another 67 million from exposure to pesticides on crops.1 (This figure does not even take into account the millions more that die from pesticides applied to golf courses, lawns, and other spaces.)

There is no credible evidence to show cats have any significant impact on bird populations.

The figures stated in the Washington Post are based on a few studies with serious flaws2: small sample sizes, limitations on how much activity has actually been observed, and methodological differences that make it virtually impossible to compare the studies or aggregate the data.

Feral cats live healthy lives in their outdoor homes.

Outdoor cats have existed alongside humans for 10,000 years.3 They are not a new phenomenon. In fact, it wasn’t until the 1940s—and the invention of cat litter—that "indoors only" for cats was even a concept.4 Feral cats don’t even belong indoors—they are not socialized to people, so they can’t be pets.

What people don’t understand about feral cats is that there will always be feral and stray cats living and thriving in every landscape, from the inner city to farmland. When people advocate for no more cats outdoors, they are actually supporting the failed policies for stray and feral cats currently in place, where cats are caught and killed.

As animal advocates, we want what’s in the best interest of all animals, including birds. That means taking a hard look at what the major threats to species are and evaluating what we as humans can do to save the environment and to change the way our choices impact our environment. It also means protecting animals—all animals—from being killed.

[1] Erickson, Wallace P., et. al. A summary and comparison of bird mortality from anthropogenic causes with an emphasis on collisions. US Forest Service General Technical Report, PSW-GTR-191, 2005.
[2] For general information on the flaws in the anti-TNR research, see Peter Wolf’s essays on, including,, and for these specific issues.
[3] Driscoll, Carlos A. et al., The Near Eastern Origin of Cat Domestication, Science Express June 28 2007.
[4] Rainbolt, Dusty. "The Best Idea. " Cat Fancy Aug. 2010 pgs. 28-32