Category: wildlife

For the past two decades, a handful of birders and “conservationists” have claimed cats kill as many as 3.7 billion birds and 22.3 billion small animals every year in the US alone.

Their claims, repeatedly credulously in the press, have been catastrophic to cats: Hyperbolic headlines have labeled them “stone cold serial killers,” “God’s perfect little killing machines,” and posed questions like “Is your cat a mass murderer?” The headlines, often running in otherwise respectable publications, envision brutal “solutions,” like this one in Scientific American: “Cats Are Ruthless Killers. Should They Be Killed?”

Politicians, wildlife conservationists and birders read headlines like the examples above and come up with ruthless policies, like bounties offering $10 for cat scalps and $5 for kitten scalps, government employees stalking public parks with shotguns and literally gunning down strays, and an Australian program designed to kill millions of cats by air-dropping sausages laced with poison.

“They’ve got to taste good,” an Australian scientist who helped develop the sausage formula said. “They are the cat’s last meal.”

Now who’s the serial killer?

Sadly, few people have thought to question the studies that claim jaw-dropping numbers of birds and small mammals are slaughtered by cats every year.

How did the studies arrive at those numbers? Their formula hasn’t varied much from “study” to “study,” and more or less looks like this:

• Assemble your data from old studies that have nothing to do with cats preying on wildlife, or hand out questionnaires to a handful of cat owners and ask them how many animals they think their free-roaming cats might kill.
• Since you don’t know how many stray, feral and free-roaming cats exist in the US, invent an arbitrary number. Most of these “studies” put the number of cats anywhere between 25 and 125 million, but higher numbers are better because they make for more apocalyptic predictions and generate more credulous headlines.
• Completely ignore the primary factors driving avian extinction in the world, which are human-caused: Habitat destruction, habitat defragmentation, wind turbines, pesticides, cars, high tension wires and windows, which are by far the biggest bird-killers.
• Attribute all of the above to feral, stray and free-roaming cats.
• Take your original “data” and, without making any adjustments for climate, regional variation, migration patterns, other predatory impacts — or anything else, really — simply extrapolate the total number of bird deaths by multiplying your small dataset by the total number of free-roaming cats in the US, which you invented back in Step 2.
• Package the entire thing as a rigorous study by Serious Conservationists, write some apocalyptic press releases and hype up your claims in your abstracts, because you know the vast majority of web aggregators and overworked reporters will not have the time to take a deep dive into the text of your study.
• Encourage activist groups and lawmakers to push for the mass culling of cats, based on your studies.

Please, don’t take my word for it. Read the text of any of the widely-cited studies that have been reported as gospel in the last 20 years. You’ll be astonished at what passes for rigorous scientific work, and how policies that determine the fates of millions of cats are largely shaped by these studies.

The D.C. Cat Count and the importance of a baseline

But there’s hope: A coalition of groups in Washington, D.C., spent more than three years methodically taking a “census” of that city’s cat population using a variety of methods.

They surveyed thousands of households within the city limits to find out how many cat owners allow their pets to roam free. They set up 1,530 trail cameras in wooded areas, ditches, alleys, alongside streams. The cameras are motion-activated and they produced more than five million images — including more than 1.2 million images of cats and more than four million images of local wildlife. The cameras captured photos of squirrels, coyotes, raccoons, possums, deer and even wild turkeys.

They assembled teams of dozens of volunteers to personally survey areas where cats are known to congregate. Then, when all the data was collected, they spent months sorting the results, carefully keeping tally, sorting duplicate sightings of individual cats and confirming data when necessary.

When all was said and done, after three years, $1.5 million and countless man-hours, the study determined there are some 200,000 cats living in Washington, D.C., and only about 3,000 of them are truly feral, meaning they’re not pets and not part of managed cat colonies.

The team — which brought together conservationists, bird lovers, cat lovers, shelter volunteers and others who would normally oppose each other on cat-related policies — also documented every step to provide a toolkit for other cities and local governments to conduct their own methodical head counts. They don’t have to reinvent the wheel to take D.C.’s admirable lead.

The leaders of the D.C. Cat Count went to all that trouble because they understood that without knowing exactly how many cats they’re dealing with, where they congregate and how they behave, any policies attempting to deal with their potential impact would be flawed and could end up doing more harm than good.

Making informed decisions about managing outdoor cats

Anyone who continues to cite the old, sloppy studies should be reminded, loudly and often, that they have led to years of failed policies, heartbreaking outcomes, enmity between cat lovers and birders, and widespread misunderstanding of how cats behave and the impact they have on wildlife.

Now the next phase begins: Dispensing with the hysteria and finding real, useful ways to minimize the predatory impact of cats on local wildlife populations.

One of the first follow-up studies to bear fruit comes, not coincidentally, from a research team in nearby Fairfax County, Virginia, and yields some surprising revelations about free-roaming cat behavior and impact.

The biggest takeaway: Because free-roaming cats almost always stick to small areas (spanning only 550 feet, or 170 meters), “cats were unlikely to prey on native wildlife, such as songbirds or small mammals, when they were farther than roughly 1,500 feet (500 meters) from a forested area, such as a park or wooded backyard. We also found that when cats were approximately 800 feet (250 meters) or farther from forest edges, they were more likely to prey on rats than on native wildlife.”

That’s it. In other words, small buffer zones are “the difference between a diet that consists exclusively of native species and one without any native prey,” the study’s authors wrote.

“Our findings suggest that focusing efforts on managing cat populations near forested areas may be a more effective conservation strategy than attempting to manage an entire city’s outdoor cat population,” wrote Daniel Herrera and Travis Gallo of George Mason University.

In other words, minimizing the predatory impact of cats is likely a hyper-local affair, and not something that can be effectively managed on a one-size-fits-all city-wide or county-wide basis.

This is just a first step in the right direction, and follow-up studies will yield further insights that will hopefully lead to fine-tuning strategies in managing free-roaming cats.

We still feel keeping cats indoors — for their own safety, as well as the safety of other animals — is the right thing to do, and all the evidence supports that view.

But what these efforts have shown us is that there is a way forward, and it’s not the contentious, divisive and irresponsible work that has guided cat management policy for two decades. It’s not just possible, but necessary, for all sides to work together to find solutions.

Let’s hope more people realize that, and the old “studies” are relegated to the dustbin where they belong.