National Geographic News
Feral cats roam the streets of Baltimore.

Feral cats roam the streets of Baltimore.

Photograph by Vincent J. Musi, National Geographic

Katia Andreassi

for National Geographic News

Published February 5, 2013

"Good for them, go cats!"

"Sorry cats but you've gotta go."

"Do you get paid to write this?"

Well, nobody ever said cat lovers were mellow. But I was taken by surprise to see the number (and intensity) of comments on National Geographic's Facebook page and Daily News website after I wrote a story about a new study on the hunting habits of the domestic cat.

To recap: Cats stand accused of killing between 1.4 billion to 3.7 billion birds and 6.9 billion to 20.7 billion mammals in the continental United States each year.

There were hundreds of comments. One reader is "sick to death of watching my neighbors cats killing migratory songbirds."

"I don't think there should be an all encompassing feline genocide," said another, "but i feel something definitely needs to be done about feral populations."

Others found the study results far from newsworthy: "Yes, all of my cats are killers. That is why I brought them home in the first place" and "I love you National Geographic, but seriously... of course my cat is gonna kill some birds."

The study has sparked strong dialogue among bird and cat groups as well.

In a press release the American Bird Conservancy called the study a "wake-up call" and said "the carnage that outdoor cats inflict is staggering and can no longer be ignored or dismissed."

Alley Cat Allies and Best Friends Animal Society both questioned the study's estimates and suggested the researchers had ulterior motives. Alley Cat Allies, which calls itself "the only national advocacy organization dedicated to the protection and humane treatment of cats," said the study was a "veiled promotion by bird advocates to ramp up the mass killing of outdoor cats." The vice-chairman of Best Friends Animal Society, a group with projects throughout the U.S., claimed "the authors and the anti-free-roaming cat contingent want stray and feral cats to be rounded up and killed." He added that "scapegoating cats is a huge and, sadly, lucrative business."

The Humane Society of the United States also weighed in, reiterating their support for the "thousands of organizations and individuals who manage cat colonies through trap-neuter-return (TNR) programs," while adding that there would be no support in those quarters for a campaign to euthanize cats.

But maybe this was never about cat people and bird people after all. "Me thinks the dog lovers came up with those figures," suggested one National Geographic reader.

Kim Beebe
Kim Beebe

Feral cat colonies pose a danger to themselves and humans in respect of disease and environmental hazards. IF you are so upset about the cats, then go be a good human and adopt a needy animal, and keep the damn thing inside, away from my nest boxes. Oh, and I will point out that cat's don't kill just birds: they are also fond of bats, which we are losing in epic numbers. Just because you love your own cat, don't let your emotions over ride common sense.

mick marsh
mick marsh

Was it a cat that invented the atom bomb, hand grenade, cluster bomb, flame thrower, gin trap, gun, germ warfare et el then? Don't start blaming animals for humanity's "development". They are merely doing what comes naturally.
Humans on the other hand, apparently the most advanced specie on the planet, want to kill each other, but not for food, not even for sport but for ideological reasons evolved via our infinitely superior brains. The human race is destroying it's own living space through greed, avarice and jealousy. Meanwhile the animals die, become extinct, starve, suffer and get abused by the most advanced specie the Earth has ever known. Since the dinosaurs. They lived on the Earth far longer than humans will. We're just an experiment ready to go wrong imminently. 

Sarah Gaines
Sarah Gaines

People spent thousands of years domesticating cats, only to dump them out on the street- hence their need to hunt birds. I quote, "the carnage that outdoor cats inflict is staggering and can no longer be ignored or dismissed." No, the carnage that humans inflict is staggering, from the first humans who abandoned their cats because they were tired of caring for them to the people everyday who opt for a cat from a breeder instead of a stray or shelter cat. People created this issue, and we should find the solution without punishing the already pitiable cats.

Jane A.
Jane A.

 Does this mean I have to get rid of my kitties? :_( PLAES NO! I LOVE MY CATZ AND THEY ARE THE ONLY REAL FRIENDS I HAVE!! THEY NEVER GO OUTSIDE ANYWAY! THE WORST THEY'VE DONE WAS EAT CAT FOOD OUT OF THE BAG! WHAT DOES IT MATTER ANYWAY! I MEAN, I LOVE BIRDS TOO BUT THERE ARE SO MANY! ONE SPECIES IS EVEN INVASIVE! Well if you trying to make a younger kid cry then well done! I guess I was meant to be the kid that sits in the corner with ABSOLUTELY NO FRIENDS!

Susan Conner
Susan Conner

I can not comprehend the intensity and prevalence of the animosity toward cats.It is something deeper than simple reaction to the behavior of a beautiful and relatively benign animal.

Most distressing is the bird vs cat clashing.

In 65 years of involvement in conservation, nature, wilderness, and birding circles, I have never encountered bird proponents of such passion. We’ve needed them so to help create healthy habitats and migratory channels.The birding groups I knew best folded long ago as members aged out and efforts to recruit younger members failed.

Most birders know cats are the least of the problems; in fact birders are more likely complaining about starlings, crows, English sparrows, pigeons.Invasive bird species are a major threat.My Mom got up at dawn to see her first bluebird fledgling scooped up by a hawk.

We have a very real looming threat of coyotes in our cities.Way overpopulated deer are spreading Lyme Disease.Bird “poop” on cars poses health threats.Invasive vines, deer, and small animals have destroyed bird feeding grounds.And still the greatest danger is humans. Think how many birds you’ve eaten this month and what sort of life they had.

We all have to work together to protect our world, to protect animals from each other, and to protect them from us.It takes work, not words.

Peggy Richter
Peggy Richter

The last paragraph pretty much destroyed the article. Either the report is good science or it isn't. Either it is accurate or it isn't. Reporting on furor over it is reasonable reporting. Adding some idiotic crack about the report being ginned up by "dog lovers" is neither reporting on the accuracy, validity or even the controversy. As a dog owner I will note that dogs "naturally" act like dingos (no surprise, dingos ARE dogs). It's long been understood that letting dogs act like dingos is not beneficial to wildlife nor to people and not even to the dogs. The view about cats however, has long been one of feeding and housing an animal that isn't expected to be really that domesticated - and like horses, feral cats acclimate pretty well back into a semi wild life. SCIENCE would have approached the issue of if this study was really impartial science and has been "falsified" or not, and SCIENCE would have addressed the difference between truly feral cats, cats that are semi feral but get food and care in part/whole by people and domestic cats. Clearly cats that live 100% in a house aren't killing wild songbirds. Clearly truly feral cats do -- as do other predators. The issue is if they are replacing natural predators (bobcats, raptors, snakes) and if they are/aren't truly threatening native wildlife, not if "dog lovers" do or don't agree with the analysis.

pacha mama
pacha mama

"the carnage that outdoor cats inflict is staggering and can no longer be ignored or dismissed.", should read as: the carnage that human beings inflict is staggering and can no longer be ignored or dismissed--that's the real wake-up call, sorry.

Rodman Papros
Rodman Papros

I remember reading an article about cats being considered cursed animals in Europe centuries back. The people resorted to killing their pets as the ultimate solution, which led to the reign of rats. Funny but the result was disastrous–Black Plague. (nothing to do with this article though)

Peter J Wolf
Peter J Wolf

It’s disappointing to see the media swallow this story without, from what I’ve seen, even the slightest hesitation. I’d be surprised if any more than, say, 10 percent of those reporting the story actually read the published paper.

This research has very little to do with science or conservation at all; framing it this way is simply Trojan Horse. At its core, this “study” was, as Alley Cat Allies has suggested, an agenda-driven effort to undermine non-lethal methods for the management of free-roaming cats.

Indeed, the authors’ astronomical “estimate” alone raises questions of credibility. The 1.4–3.7 billion annual mortalities reported by these researchers (which the authors describe throughout their paper as a conservative estimate) represent an astonishing 28.5–75.5 percent of the estimated 4.7 billion landbirds in all of North America. [1]

Were these figures even remotely accurate, the continent would have been devoid of birds long ago.

If any reporter had asked about this—something that strikes me as the most obvious of follow-ups—I’ve not seen the story.

A careful examination of the model used reveals one inflated input after another, each one the result of the researchers’ very selective review of the literature on the subject. Peter Marra’s claim that 40 to 70 percent of pet cats are indoor-outdoor, for example, ignores several well-known surveys (including two cited by Marra and his co-authors) demonstrating just the opposite: approximately 60 percent of America’s pet cats are indoor-only, and the trend is upward. [2, 4] And about half of the cats allowed outside are outdoors for three hours or less each day. [2, 3]
And that’s just the beginning. Garbage in, garbage out, as they say in the computer science field.

Late last year, these same authors published another paper in which they pointed out, correctly, that “national mortality estimates are often based on extrapolation from a limited sample of small-scale studies, and estimates of uncertainty are ignored or only superficially assessed.” [5]

It’s more than a little ironic, then, that Loss, Will, and Marra include some of these very studies in their more recent analysis. And by pooling studies from various contexts, they actually add to the uncertainty they once seemed to find detrimental to “decision making about policies and regulations aimed at reducing avian mortality and minimizing population impacts.” [5]

But that’s not the only irony here. Two of these three authors (Marra and Will) have advocated publicly for restrictions or outright bans on the feeding of outdoor cats and the trap-neuter-return method of free-roaming cat management. [6, 7] Such policies would, it’s virtually guaranteed, actually increase the risk to the wildlife they claim to want to protect.

The real story here is about how such junk science is funded (by U.S. taxpayers), published, and sold to the public.

Peter J. Wolf  

Literature Cited
1.    T.D. Rich, C.J.B., H. Berlanga, P.J. Blancher, M.S. W. Bradstreet, G.S. Butcher, D.W. Demarest, and E.H. Dunn, W.C.H., E.E. Iñigo-Elias, J.A. Kennedy, A.M. Martell, A.O. Panjabi, D.N. Pashley, K.V. Rosenberg, C.M. Rustay, J.S. Wendt, T.C. Will., Partners in Flight North American Landbird Conservation Plan. 2004, Cornell Lab of Ornithology: Ithaca, NY.
2.    Clancy, E.A., Moore, A.S., and Bertone, E.R., "Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats." Journal of the American Veterinary Medical Association. 2003. 222(11): p. 1541-1545.
3.    Lord, L.K., "Attitudes toward and perceptions of free-roaming cats among individuals living in Ohio." Journal of the American Veterinary Medical Association. 2008. 232(8): p. 1159–1167.
4.    APPA, 2009–2010 APPA National Pet Owners Survey. 2009, American Pet Products Association: Greenwich, CT.
5.    Loss, S.R., Will, T., and Marra, P.P., "Direct human-caused mortality of birds: improving quantification of magnitude and assessment of population impact." Frontiers in Ecology and the Environment. 2012. 10(7): p. 357–364.
6.    Marra, P. (2011, March 18). No good for the birds, but also no good for the cats (Opinion). The Washington Post, from
7.    Will, T., What Can Federal Agencies Do? Policy Options to Address Cat Impacts to Birds and Their Habitats, in Bird Conservation Alliance Teleconference. 2010.

lola marjanovic
lola marjanovic

cats eat that really so bad to you people

Anthony Massie
Anthony Massie

Get real, cat lovers. There are at least 50 million feral cats in the US. That is 30 birds killed annually per feral cat (not to mention house cats that are allowed to roam free outside.) This number does not sound exaggerated one bit. Do you really think a feral cat is not capable of killing three birds a month?

Eugene Wilson
Eugene Wilson

@Peggy Richter  maybe reread that part about the dogs ( "Me thinks the dog lovers came up with those figures," suggested one National Geographic reader.) it wasn't the authors opinion

Peggy Richter
Peggy Richter

@Rodman Papros - the black plague was as much due to lack of sanitation and the introduction of a new disease as anything else.  Terriers and ferrets could have managed the rodents but these weren't seen as a problem.  Was the widespread deaths by flu post WWI due to lack of cats? or was it due (as was the plague) by infected people not being isolated, lack of good treatment for victims, lack of sanitation, and good housekeeping? You surely aren't asserting that the ONLY way to control rodents is cats? 


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