Freedom of the Press (Release)

Among the many news stories, research studies, and government reports brought to my attention last week was an article in Monday’s Toronto Star (thanks, once again, to the good folks at Alley Cat Rescue, who routinely put Google Alerts to shame!). What I find compelling about the article is not its central story (another community struggles with their “feral cat problem”), but the way it illustrates so much of what’s wrong with the free-roaming/feral cat/TNR debate.

In a nutshell, the story is about the town of Oakville changing its bylaws so that cats are no longer allowed to roam free. Wrong-headed policy, in my opinion—but more problematic is the case being made for this policy: what’s being said, how it’s being said, and by whom.

Déjà Vu
One doesn’t have to read further than the first line—“Sylvester and Tweety almost got it right”—to know that this is one of those stories. The kind of story that uses corny references to downplay the implications of a large-scale witch hunt. The kind of story that, frankly, makes it tough to feel much sympathy for a newspaper industry struggling for survival.

“In their cartoon world, the brainy yellow bird always outsmarts the puddy tat. In the real world, the cat kills the canary—and as many as one million birds daily in North America. This is causing a growing, sometimes violent, rift between animal lovers.”

Where that one-million-birds-per-day rate comes from is anybody’s guess, though it sounds awfully familiar—more than likely, one of American Bird Conservancy’s talking points. As for the “violent rift” reporters Mary Ormsby and Jim Wilkes refer to, that comes later.

“The crucial question: Should cats, which are natural hunters, be allowed to freely to roam the streets?”

It’s a fair question, but it’s not as if cats are the only natural hunters found in urban areas. In Chicago, for example, more than 60 coyotes are “roaming parks, alleys, yards and thoroughfares.” (The NPR story claims that coyotes kill area dogs and cats only “every so often,” but in light of Judith Webster’s 2007 paper “Missing Cats, Stray Coyotes: One Citizen’s Perspective,” I’m quite skeptical of such assertions.)

And then, of course, there are the raptors—birds of prey (which are attracted by, among other things, bird feeders—but I’ll get to that shortly).

All Sticks, No Carrots
Progressive animal service organizations have figured out that charging people to house their stray animals (i.e., the “traditional” approach) only hurts the animals and the community at large. Like mandatory spay-neuter laws, it’s great on paper but disastrous in practice.

Yet, this is precisely the direction (read: backwards) Oakville is taking.

“Owners whose loose cats repeatedly end up at the Oakville shelter can be fined $105, plus a $30 town surcharge, a return fee of $25 and $15 for each day the cat stays at the shelter.”

Such a policy virtually guarantees a dramatic increase in intakes—and killing.

“Johanne Golder, executive director of the Oakville and Milton Humane Society, which is contracted by Oakville to provide animal control services… said the mentality that cats are “disposable” pets (unwanted kittens are often abandoned or dumped at shelters) is to blame for the huge feline populations in urban centres.”

Again, a fair point—but I fail to see how the proposed “solution” will improve the situation. And it’s very likely to be a death sentence for the area’s feral cats.

Witch Hunt
Readers who might have similar misgivings are (presumably) set straight when Ormsby and Wilkes explain the threats posed by free-roaming cats:

“The more cats, the fewer birds, said McGill University avian expert David Bird. He said house pets are just as bloodthirsty as untamed ferals—homeless offspring of stray or abandoned cats raised without human contact. Bird (his surname and passion are coincidental, he chirped) estimated well-fed pets alone destroy upwards of a billion birds annually around the world. The American Bird Conservancy (ABC) estimates hundreds of millions are killed in the United States by cats each year but says an exact figure is unclear.”

“Unclear” is right! Anybody even vaguely familiar with the subject would agree that “an exact figure is unclear.” But for Bird to suggest that it’s even possible—or meaningful—is ridiculous. And highly irresponsible. Are we talking about islands or continents? Which part of the world? Rare or common species? Healthy or unhealthy birds? Etc.

And what’s the impact of this predation?

This is ABC’s kind of science: one that strives not for an increased degree of certainty, but greater ambiguity—while at the same time painting a decidedly grim picture. There’s a name for this, of course: propaganda.

Which is precisely what Bird advocates for in “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Along with his nine co-authors, Bird calls on conservation biologists to “begin speaking out” against TNR “at local meetings, through the news media, and at outreach events.” [1]

(Late last year, co-author Peter Marra earned his Propaganda Badge via a Washington Post article, though the research findings he cited there have since been removed from the Smithsonian Migratory Bird Center’s website.)

Rhetoric
Just as important as Bird’s absurd claim, though, is the language used. Indeed, it was the word bloodthirsty that rankled Alley Cat Rescue founder Louise Holton. And there’s plenty more where that came from:

“Bird, the author of The Bird Almanac and Birds of Canada, said the cat-on-bird carnage is as common in quiet residential cul-de-sacs as it is in the countryside.

I’d created a killing field in my own backyard,” recalled the wildlife biology professor, who once spotted four neighbourhood cats stalking finches, woodpeckers, nuthatches, juncos, jays and cardinals nibbling at feeders around his west Montreal home.”

Really, a killing field? Somehow, I don’t think any birds were killed at all. Had any harm come to his birds, I have no doubt Bird would have let readers know in no uncertain terms. This sounds like a Winterism: the careful arrangement of true statements for the purpose of creating a false impression.

Then, too, stalking is not catching or killing, as Fitzgerald and Turner point out:

“Hunting for birds requires stalking, since many species of birds have an up to 360˚ field of view and can detect a cat approaching them from behind [2]… The ‘wait’ just before the pounce is a characteristic element of the cat’s hunting behaviour and many birds also fly away during this ‘wait’ without ever having noticed the cat. Because of these failures, many cats soon give up bird hunting altogether.” [3]

Us and Them
When Bird complains, “I didn’t think it was right for other people’s hobby interest, i.e., owning a pet cat, to impinge upon my interests on my own property,” he betrays his profoundly myopic world view as much as any property rights concern he might have. Cat ownership a hobby interest? Tell that to the 38.2 million U.S. households owning, collectively, something like 94 million cats (my apologies—I don’t have statistics for Canada), which are, increasingly, treated like members of the family.

Is it any wonder “bird people” and “cat people” (classifications I use with some hesitation) have such difficulties communicating?

Bird seems to imply that his bird feeders are inherently benign—but again, that’s from his point of view. “Feeding birds is,” according to the Cornell Lab of Ornithology’s website, “a wonderful way to get to know your birds better! But, bird feeders can also be deadly.”

“Predators (cats, hawks, even dogs) can easily find birds at feeders, dirty feeders can spread disease, feeders can attract non-native, invasive species (house sparrows, brown-headed cow birds, and starlings for instance) which can be detrimental to native birds, and birds might fly away quickly and crash into nearby windows.”

How different is this from the “rationale” typically used to ban the feeding of feral cats? If feeding feral cats is in imposition on the community at large, then so are bird feeders. Should communities require people feeding birds to apply for permits, just as city officials in Yuma, AZ, want to require permits for those conducting TNR?

The way Ormsby and Wilkes tell it, though, birders are up against some kind of powerful cat lobby:

“Bird advocates like him are up against a multi-million-dollar cat-care industry in an animal rights fight that has been tested in U.S. courts, written about in a best-selling novel and spawned an outdoor furniture business to erect enclosed “catios” to give kitty a breath of fresh air.”

Had the reporters followed the money, they would have found a very different story on the advocacy front. According to the most recent data available from Charity Navigator, Alley Cat Allies’ net assets (as of July 2009) were about $2.8 million, compared to $3.7 million for ABC (December 2009). And the National Audubon Society holds in excess of $255 million (June 2009).

All of the sudden, that “multi-million-dollar” characterization doesn’t mean so much.

Cat Crazed
To further their case, Ormsby and Wilkes turn to Maureen Palmer, director of the recently released documentary Cat Crazed (currently unavailable for online streaming outside of Canada, though an audio interview with Palmer is available via the CBC).

“Palmer said one of the most ‘heartbreaking’ scenes during filming was at a volunteer spay-neuter clinic in Los Angeles that sterilized 80 ferals a day. She said most of the cats had infections that never healed, as well as broken bones, large abscesses around their teeth and mange.”

That does sound heartbreaking. But is it true?

I contacted Kim Senn, VP of Operations at FixNation, the clinic Palmer visited for the film. “We are fixing between 70–80 cats a day at FixNation,” she told me via e-mail, “and the overwhelming majority of them are healthy.”

“Less than 5 percent have any medical issues that prevent us from sterilizing them. The common, non-life-threatening issues we do see—like fleas, mange or an occasional abscess—are easily treatable while the cat is here at our clinic, and the cat is left better off than before TNR. And no longer reproducing, which is the best part.”

Immigration Status
Ormsby and Wilkes also touch on one of the most threadbare complaints against free-roaming and feral cats: their “status” as non-native. (Stay tuned for a follow-up story detailing (1) the exact date and time when North America was “pristine,” and (2) precisely how we might return to that mythical Eden.)

“Cats actually never roamed freely in North America until they were introduced by humans. The animals—rodent hunters in the wild—were first domesticated 7,000 years ago in the Middle East and Africa, according to researchers at the University of Nebraska. Those ancient cats evolved into a separate species called the domestic or house cat.”

Of all the possible sources the Toronto Star could consult about the history of the domestic cat, they turned to the authors of “Feral Cats and Their Management”? Isn’t that a bit like consulting Michael Vick about the history of the American Pit Bull Terrier?

“Since cats are not native predators in this part of the world, nesting North American birds have no natural defences against the agile tree climbers. Birds are already under stresses from habitat destruction, pollution, climate change and other animals, such as squirrels, who eat unattended eggs.”

Here, it seems, Ormsby and Wilkes have gone off the deep end, taking an argument used to explain the significant impact cats can have on island populations of birds and other animals—literally—to another level. As Fitzgerald and Turner write:

“Any bird populations on the continents that could not withstand these levels of predation from cats and other predators would have disappeared long ago, but populations of birds on oceanic islands have evolved in circumstances in which predation from mammalian predators was negligible and they, and other island vertebrates, are therefore particularly vulnerable to predation when cats have been introduced.” [3]

At the risk of stating the obvious: birds can fly—at least the ones found in trees can. That’s quite a defense against cats—less so against raptors, of course. Or buildings, pesticides, power lines, wind farms, etc.

Life Imitates Art
Ormsby and Wilkes quote Jonathan Franzen, whose latest novel, Freedom, touches rather directly on, as they put it, “the tension between cat people and bird people.”

There are many ways for a house cat to die outdoors, including dismemberment by coyote and flattening by a car but when the Hoffbauer family’s beloved pet Bobby failed to come home one early-June evening, and no amount of calling Bobby’s name or searching the perimeter of Canterbridge Estates or walking up and down the county road or stapling Bobby’s Xeroxed image to local trees turned up any trace of him, it was widely assumed on Canterbridge Court that Bobby had been killed by Walter Berglund.”

Actually, Franzen is more of an insider than the reporters let on; Franzen, winner of the 2001 National Book Award and a Pulitzer Prize finalist the following year, sits on ABC’s board of directors, and he wrote the foreword to their recently released book, The American Bird Conservancy Guide to Bird Conservation (brilliant move: ABC has been publishing fiction for years now; at last, they have somebody on board who does it well). Franzen is also a fervent believer.

Ormsby and Wilkes end their article with a brief summary of a 2007 animal cruelty case that made headlines across the U.S. and beyond.

“In Texas five years ago, Jim Stevenson killed a cat. The Galveston ornithologist fatally shot a feral with a .22-calibre rifle, claiming the creature was killing piping plovers, an endangered shorebird species. Stevenson was charged with animal cruelty but walked free in 2007 when jurors failed to come to a decision and a mistrial was declared.”

Rather a dry telling of it, if you ask me. After hearing of bloodthirsty cats, backyard killing fields, and all the rest, aren’t readers entitled to a little more drama? Here, after all, is the only evidence of that “violent rift” Ormsby and Wilkes referred to early on—though, of course, it’s far more one-sided than the reporters suggested with their ominous foreshadowing.

That “feral,” by the way, was part of a colony cared for by John Newland, who, according to Assistant District Attorney Paige Santell, “had fed them, watered them, provided shelter for them, provided toys for them, provided vet care for some of them.”

“This animal suffered a great deal,” says Santell, during an interview with Alley Cat Allies. “That was another part of this case. I mean, this animal did not die right away. It took, you know, 30 to 45 minutes before it died. It was in a terrible amount of pain.”

It must be that Ormsby and Wilkes had hit their word limit already—it’s not as if they don’t like a good story.

The High Cost of a Free Press
Whether Ormsby and Wilkes were unable or unwilling to do this story justice I can’t say, but, as a piece of journalism, their finished product is astonishingly bad.

Not that they’re alone. On the contrary, they have plenty of company.

Last year around this time, when the Los Angeles Times ran a story about the injunction against city-funded TNR, reporter Kimi Yoshino invoked Sylvester and Tweety. And swallowed in one gulp the ridiculous claim by ABC’s Steve Holmer that “there are about . . . 160 million feral cats [nationwide].”

In December, several newspapers treated “Feral Cats and Their Management” as if it were legitimate research. Among the worst were Dale Bowman’s column in the Chicago Sun-Times (December 6), Scott Shalaway’s column (December 12) in the Pittsburgh Post-Gazette, and an editorial (unsigned for good reason) in Lincoln’s Journal-Star (December 7).

And, it just keeps on coming.

Even as I was working on this post, somebody alerted me, via the Vox Felina Facebook page, to an opinion piece in the London Free Press (in which “expert” Theo Hofmann comes up short on both facts and logic: “Cats don’t eat the birds, they just kill them… So they really are causing a great deal of damage…”).

Do news accounts of cats killing a million birds a day turn ordinary citizens into Jim Stevensons? Or reports of 160 million feral cats (one for every two humans in this country!) provoke the kinds of horrors chronicled on the Cat Defender blog? Of course not.

On the other hand, the cumulative effect of such news coverage surely contributes to a misinformed public/electorate. Which, in turn, paves the way for misguided policy. (See, for example, Utah’s House Bill 210, sponsored by Republican Curtis Oda, which proposed to relax “provisions of the Utah Criminal Code relating to animal cruelty and animal torture,” in order to allow, among other things, “the humane shooting or killing of an animal if the person doing the shooting or killing has a reasonable belief that the animal is a feral animal.”)

Journalists have an obligation to approach any story with some healthy skepticism. They owe it to their readers to set aside, as much as possible, their own biases—and challenge those of their sources. To bring to the table some critical thinking and professional integrity.

When it comes to the subject of free-roaming/feral cats/TNR, however, the public rarely gets anything more substantive than a one-sided collection of talking points, sprinkled with cartoon references.

Literature Cited
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627–629. www.abcbirds.org/abcprograms/policy/cats/pdf/Lepczyk-2010-Conservation%20Biology.pdf

2. Tabor, R., The Wild Life of the Domestic Cat. 1983, London: Arrow Books.

3. Fitzgerald, B.M. and Turner, D.C., Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press: Cambridge, U.K.; New York. p. 151–175.

Revisiting “Reassessment”

“Reassessment: A Closer Look at ‘Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return’” has been revised and expanded!

Image of "Reassessment" Document

This paper, a brief review and critique of the essay “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” by Travis Longcore, Catherine Rich, and Lauren M. Sullivan, now includes sections on Toxoplasma gondii, the mesopredator release phenomenon, and more. In addition, links and downloadable PDFs have been added to the list of references.

Over the past year, “Critical Assessment” has gotten a great deal of traction among TNR opponents, despite its glaring omissions, blatant misrepresenta­tions, and obvious bias. “Reassessment”—intended to be a resource for a broad audience, including, wildlife and animal control professionals, policymakers, and the general public—shines a bright spotlight on these shortcomings, thereby bringing the key issues back into focus.

Act Locally
Politics is, as they say, local. This is certainly true of the debate surrounding TNR. Policies endorsing TNR, the feeding of feral cats, etc. typically begin with “Town Hall” meetings, or even meetings of neighborhood associations. “Reassessment” provides interested parties with a rigorous, science-based counter-argument to those using “Critical Assessment” as a weapon against feral cats/TNR.

So, once you’ve had a look for yourself, please share generously! Together, we can—in keeping with the mission of Vox Felina—improve the lives of feral cats through a more informed, conscientious discussion of feral cat issues in general, and TNR in particular.

Download PDF

On Invasion and Persuasion

Smithsonian magazine is, according to its website, “created for modern, well-rounded individuals with diverse interests” and “chronicles the arts, history, sciences and popular culture of the times.” Jess Righthand’s recent article, “The World’s Worst Invasive Mammals,” seems—despite its inclusion in the online edition’s “Science & Nature” section—better suited for the pop culture category.

Indeed, the story has more to do with sensationalism than science.

Feral Cat Population
Righthand’s claim that “there are an estimated 60 million feral cats in the United States alone” is conservative compared to some other estimates. David Jessup, for example, suggested in 2004 that there were 60–100 million [1], while, more recently, The American Bird Conservancy Guide to Bird Conservation puts the figure at 60–120 million [2] (neither cites a source).

Still, Merritt Clifton of Animal People, an independent newspaper dedicated to animal protection issues, makes a compelling argument that the population of feral cats in the U.S. is much smaller than is often reported, and may very well be on the decline. [3]

Clifton’s estimates are derived not from surveys of homeowners feeding stray and feral cats, but from “information about the typical numbers of cats found in common habitat types, gleaned from a national survey of cat rescuers… cross-compared with animal shelter intake data.” [4] In 2003, Clifton suggested that “the winter feral cat population may now be as low as 13 million and the summer peak is probably no more than 24 million.” [4]

Predation on Birds
Righthand puts the figure for annual bird deaths attributed to feral cats at “around 480 million.” Nowhere near the “one billion birds” proposed by Nico Dauphine and Robert Cooper, [5] of course, but more than enough to get the attention of Smithsonian readers.

But, as I’ve pointed out repeatedly, even high rates of predation do not equate to population declines (though, clearly, it’s easy to suggest as much). Many researchers have disputed the kind of broad, overreaching claims to which Righthand alludes. Biologist C.J. Mead, for example, reviewing the deaths of “ringed” (banded) birds reported by the British public, suggests that cats may be responsible for 6.2–31.3 percent of bird deaths. “Overall,” writes Mead, “it is clear that cat predation is a significant cause of death for most of the species examined.” Nevertheless, Mead concludes:

“there is no clear evidence of cats threatening to harm the overall population level of any particular species… Indeed, cats have been kept as pets for many years and hundreds of generations of birds breeding in suburban and rural areas have had to contend with their predatory intentions.” [6]

Mike Fitzgerald and Dennis Turner come to essentially the same conclusion: “We consider that we do not have enough information yet to attempt to estimate on average how many birds a cat kills each year. And there are few, if any studies apart from island ones that actually demonstrate that cats have reduced bird populations.” [7]

Then, too, there’s the critical distinction between compensatory and additive predation—again, a point I’ve made numerous times. Two very interesting studies have generated compelling evidence that birds killed by cats are, on average, significantly less healthy than those killed through non-predatory events (e.g., collisions with buildings). [8, 9] In other words, these birds probably weren’t going to live long enough to contribute to the overall population numbers; predation was compensatory rather than additive.

Public Health Threats
“When house cats are allowed free range outdoors by their owners,” argues Righthand, “or simply don’t have owners, they not only wreak havoc as opportunistic hunters, they can also spread disease. In addition to carrying rabies, 62 to 82 percent of cats in a recent study tested positive for toxoplasmosis.” Here, Righthand seems to be cribbing off of Hildreth, Vantassel, and Hygnstrom, of “Feral Cats and Their Management” fame—hardly a reputable source.

Rabies
Regarding rabies—a topic I’ll save for future posts—I think it’s important to put this into perspective. I happen to have data from Florida handy, and according to that state’s Department of Health, approximately 22,000 Florida residents have died of the flu or pneumonia since 2006 (actually, that figure accounts for only 24 of Florida’s 67 counties, so the total is surely much higher).

By way of comparison: from 2005 through mid-May of this year, there were 11 reported cases of rabies in humans across the entire country (though, I believe there were a handful of reported cases this summer as well).

In terms of public health, then, I think we’re all better off focusing on frequent hand washing, sneezing into our sleeves, and the like—as opposed to, say, exterminating this country’s most popular companion animal by the millions.

Toxoplasma gondii (I)
While it’s true that cats are the definitive host of Toxoplasma gondii, it’s important to note that “wild game can be a source of T. gondii infection in humans, cats, and other carnivores. Serologic data show that a significant number of feral pigs, bears, and cervids are exposed to T. gondii. [10]

“Humans,” write Elmore et al., “usually become infected through ingestion of oocyst-contaminated soil and water, tissue cysts in undercooked meat, or congenitally. Because of their fastidious nature, the passing of non-infective oocysts, and the short duration of oocyst shedding, direct contact with cats is not thought to be a primary risk for human infection.” [11]

But to Righthand’s point: the rate of cats testing positive—or seroprevalence—is, in any event, not a useful measure of their ability to infect other animals or people.

According to Dubey and Jones, “most cats seroconvert after they have shed oocysts. Thus, it is a reasonable assumption that most seropositive cats have already shed oocysts.” [12] “Testing positive,” in this case, is nothing more than the detection of antibodies resulting from seroconversion (the same process, by the way, that takes place in humans after receiving a flu shot).

So, what exactly is Righthand’s point? Did she simply not do her homework here, or is the idea to portray these cats as a threat far, far beyond what the scientific evidence supports? Both, I suspect.

Toxoplasma gondii (II)
T. gondii
, Righthand continues, “has been shown to cause neurological damage to sea otters and other marine mammals that are exposed when heavy rainfall washes infected cat feces into the water.” Again, this is terrain I’ve covered previously. (Righthand, it seems, could do herself—and Smithsonian readers—a favor by subscribing to Vox Felina!)

Yes, T. gondii has been linked to the illness and death of marine life, primarily sea otters [13], prompting investigation into the possible role of free-roaming (both owned and feral) cats. [14, 15] It’s generally thought that oocysts (the mature, infective form of the parasite) are transferred from soil contaminated with infected feces to coastal waterways by way of freshwater run-off. [15]

However, one study found that 36 of 50 sea otters from coastal California were infected with the Type X strain of T. gondii [16], a type linked to wild felids (mountain lions and a bobcat, in this case), but not to domestic cats. [15] A recently published study from Germany seems to corroborate these findings. Herrmann et al. analyzed 18,259 fecal samples (all from pet cats) for T. gondii and found no Type X strain. (It’s interesting to note, too, that only 0.25% of the samples tested positive for T. gondii). [17]

Once again, we’re back to the question: What is Righthand trying to accomplish here?

Population Impacts
“Cats have,” writes Righthand, “also hurt populations of birds, reptiles and other creatures. The black stilt of New Zealand (a seabird), the Okinawa woodpecker and the Cayman Island ground iguana are just a few of the dozens of endangered species at risk due to the proliferation of feral cats.”

At the risk of pointing out the obvious, endangered species are—by definition—at risk due to the proliferation of all sorts of threats. That’s how they became endangered in the first place. To suggest, as Righthand does, that cats are the sole threat these animals face is both misleading and irresponsible.

Righthand (taking a cue, perhaps, from the authors of The ABC Guide?) also makes the common mistake of using island impacts (which are, themselves, more complex than often acknowledged) to imply impacts elsewhere (better yet: everywhere). Readers, it seems, are on their own in terms of doing any research on the topic.

Mission Failure
How much of the blame we can put on Righthand, I don’t know. According to Smithsonian’s website, she’s an intern with the magazine. Had the editors wanted a more thoroughly researched article, they could have demanded one. (This, some readers will recall, is not the first time I’ve been disappointed with the Smithsonian’s lack of rigor.)

According to its website, the mission of the Smithsonian is straightforward but ambitious: “the increase and diffusion of knowledge.” Righthand’s article—misleading at best—falls well short. It seems she’s still struggling with how to best express the organization’s proclaimed values—in this case, going overboard on the creativity at the expense of excellence and integrity.

Literature Cited
1. Jessup, D.A., “The welfare of feral cats and wildlife.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1377-1383. http://avmajournals.avma.org/doi/abs/10.2460/javma.2004.225.1377

2. Lebbin, D.J., Parr, M.J., and Fenwick, G.H., The American Bird Conservancy Guide to Bird Conservation. 2010, London: University of Chicago Press.

3. Clifton, M. (2003) Roadkills of cats fall 90% in 10 years—are feral cats on their way out? http://www.animalpeoplenews.org/03/11/roadkills1103.html Accessed May 23, 2010.

4. Clifton, M. Where cats belong—and where they don’t. Animal People 2003 [cited 2009 December 24].  http://www.animalpeoplenews.org/03/6/wherecatsBelong6.03.html.

5. Dauphiné, N. and Cooper, R.J., Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations, in Fourth International Partners in Flight Conference: Tundra to Tropics. 2009. p. 205–219. www.pwrc.usgs.gov/pif/pubs/McAllenProc/articles/PIF09_Anthropogenic%20Impacts/Dauphine_1_PIF09.pdf

6. Mead, C.J., “Ringed birds killed by cats.” Mammal Review. 1982. 12(4): p. 183-186. http://dx.doi.org/10.1111/j.1365-2907.1982.tb00014.x

7. Fitzgerald, B.M. and Turner, D.C., Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press: Cambridge, U.K.; New York. p. 151–175.

8. Baker, P.J., et al., “Cats about town: is predation by free-ranging pet cats Felis catus likely to affect urban bird populations? Ibis. 2008. 150: p. 86-99. http://dx.doi.org/10.1111/j.1474-919X.2008.00836.x

9. Møller, A.P. and Erritzøe, J., “Predation against birds with low immunocompetence.” Oecologia. 2000. 122(4): p. 500-504. http://www.springerlink.com/content/ghnny9mcv016ljd8/

10. Hill, D.E., Chirukandoth, S., and Dubey, J.P., “Biology and epidemiology of Toxoplasma gondii in man and animals.” Animal Health Research Reviews. 2005. 6(01): p. 41-61. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=775956&fulltextType=RA&fileId=S1466252305000034

11. Elmore, S.A., et al., “Toxoplasma gondii: epidemiology, feline clinical aspects, and prevention.” Trends in Parasitology. 26(4): p. 190-196. http://www.sciencedirect.com/science/article/B6W7G-4YHFWNM-1/2/2a468a936eb06649fde0463deae4e92f

12. Dubey, J.P. and Jones, J.L., “Toxoplasma gondii infection in humans and animals in the United States.” International Journal for Parasitology. 2008. 38(11): p. 1257-1278. http://www.sciencedirect.com/science/article/B6T7F-4S85DPK-1/2/2a1f9e590e7c7ec35d1072e06b2fa99d

13. Jones, J.L. and Dubey, J.P., “Waterborne toxoplasmosis – Recent developments.” Experimental Parasitology. 124(1): p. 10-25. http://www.sciencedirect.com/science/article/B6WFH-4VXB8YT-2/2/8f9562f64497fe1a30513ba3f000c8dc

14. Dabritz, H.A., et al., “Outdoor fecal deposition by free-roaming cats and attitudes of cat owners and nonowners toward stray pets, wildlife, and water pollution.” Journal of the American Veterinary Medical Association. 2006. 229(1): p. 74-81. http://avmajournals.avma.org/doi/abs/10.2460/javma.229.1.74

15. Miller, M.A., et al., “Type X Toxoplasma gondii in a wild mussel and terrestrial carnivores from coastal California: New linkages between terrestrial mammals, runoff and toxoplasmosis of sea otters.” International Journal for Parasitology. 2008. 38(11): p. 1319-1328. http://www.sciencedirect.com/science/article/B6T7F-4RXJYTT-2/2/32d387fa3048882d7bd91083e7566117

16. Conrad, P.A., et al., “Transmission of Toxoplasma: Clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment.” International Journal for Parasitology. 2005. 35(11-12): p. 1155-1168. http://www.sciencedirect.com/science/article/B6T7F-4GWC8KV-2/2/2845abdbb0fd82c37b952f18ce9d0a5f

17. Herrmann, D.C., et al., “Atypical Toxoplasma gondii genotypes identified in oocysts shed by cats in Germany.” International Journal for Parasitology. 2010. 40(3): p. 285–292. http://www.sciencedirect.com/science/article/B6T7F-4X1J771-2/2/dc32f5bba34a6cce28041d144acf1e7c

Conversation Killer

Over the weekend, a comment (criticizing, once again, the recently released University of Nebraska-Lincoln “report”) I posted on Audubon magazine’s blog, The Perch, drew fire from Travis Longcore.

Longcore, of course, is the lead author of the widely circulated paper, “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” and Science Director for the Urban Wildlands Group, the lead plaintiff in the case that led to the TNR-related injunction in Los Angeles earlier this year (under which City-funded spay/neuter vouchers for feral cats and shelter-based TNR promotions have been halted; TNR, however, continues), a decision currently making its way through the appeal process (I heard just this afternoon that “Round 2” was decided in favor of the plaintiffs).

After a weekend of back-and-forth debate about the science surrounding the UNL report and, more broadly, feral cats and TNR, I posed the following question to Longcore:

You’ve been very straightforward about your desire to see TNR and the feeding of feral cats outlawed. But then what?

I’ve yet to hear from you—or anybody on your side of the issue—spell it out. We all know the cats won’t disappear in the absence of TNR/feeding. We can argue about rates of population growth, carrying capacity, etc.—but let’s keep it simple here. Under your plan, there are these feral cats—an awful lot of them—that no longer have access to the assistance of humans (other than scavenging trash, say). OK, now what?

Will it be like what was done on Marion Island, where—despite being only 115-square-miles in size, barren, and uninhabited—it took something like 16 years to eradicate 2,500 cats? Using disease (feline distemper), poisoning, intensive hunting and trapping, and—if I’m not mistaken—dogs.

And, while we’re at it, who will pay for this unprecedented nightmare?

These are not rhetorical questions. As I say, I’ve heard plenty of arguments against TNR over the past year or so. I’ve yet to hear a single counter-proposal. Not one.

Trap-and-remove? That’s not a proposal—that’s a bromide. I want to hear about how all this would play out. And this seems like an appropriate venue, given the original topic and your role in the L.A. injunction.

So, Travis, what would you do?

Two days later, no word from Longcore. a well-considered reply, but still no answer to the question posed.

Docs’ Docs

The American Veterinary Medical Association (AVMA) recently made available online (via downloadable PDFs) several of its articles related to free-roaming cats/TNR. Although abstracts have been online for some time, access to the full text for these papers has generally required either a subscription to the Journal of the American Veterinary Medical Association or access to a subscribing library.

Among the articles that make up this edition of AVMA Collections are several I’ve referred to over the past few months—including two I’ve been quite critical of: one by Linda Winter, former director of the American Bird Conservancy’s Cats Indoors! campaign, and another by David Jessup.

The AVMA and Free-roaming Cats
Although “the AVMA encourages and supports actions to eliminate the problem of free-roaming abandoned and feral cats,” its policy regarding Free-roaming Abandoned and Feral Cats is, it must be said, ambivalent at best. The organization “neither endorses nor opposes appropriately managed cat colony programs,” for example. When it comes to the “treatment” of cats not in managed colonies, however, the AVMA is quite clear—as is the likely fate of these cats (despite the policy’s euphemistic language):

“The AVMA strongly supports reducing the number of unowned free-roaming abandoned and feral cats through humane capture (with placement in homes where appropriate) by local health departments, humane societies, and animal control agencies. All free-roaming abandoned and feral cats that are not in managed colonies should be removed from their environment and treated in the same manner as other abandoned and stray animals in accord with local and state ordinances.”

Another worrisome aspect of the AVMA’s policy is its matter-of-fact assertion that “these free-roaming abandoned and feral cats also represent a significant factor in the mortality of hundreds of millions of birds, small mammals, reptiles, amphibians, and fish” (the wording of which matches almost exactly a claim made by the American Bird Conservancy).

*     *     *

As with all large, politically-minded organizations, policy change at the AVMA is likely to be a slow process. Perhaps, though, by making this collection of articles available to the general public, they have, knowingly or not, given that process a nudge. Regardless of its intent—which seems to consider only a veterinary professional readership—the AVMA’s move may help foster a better-informed, more engaged debate among those outside the profession.

Out-Sciencing the Scientists

Although it’s taken me two months to respond, it took less than two weeks for Vox Felina to come under attack by feral cat/TNR opponent Michael Hutchins, CEO and Executive Director of The Wildlife Society. In his post, Hutchins accuses me of trying to “out-science the scientists,” and refers to my critique of the essay “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” as “a flawed analysis, which could have been written by a high school biology student, and not a very good one at that.”

Hutchins goes on to write:

“Unless the author, who is obviously not a trained scientist himself, can publish a strong and verifiable critique of the Longcore et al. paper in the peer-reviewed wildlife biology/ecology literature, all of his arguments must be taken with a gigantic grain of salt.”

In the weeks since Hutchins’ post, I’ve gone to some length to point out some of the more blatant instances of errors, misrepresentations, and bias in the wildlife biology/ecology literature he defends. As this seven-part series, called “The Work Speaks,” (beginning with this post) makes clear, Hutchins’ had better have plenty more salt on hand as he reviews the work of his colleagues.

In the interest of transparency, then, here is my response—as an open letter—to Hutchins’ May 3rd post:

Dear Michael,

Let me begin by introducing myself. My name is Peter J. Wolf, and I’m the writer behind the Vox Felina blog. I’d like to address some of the points you made in your May 3rd critique of my work. (In the interest of transparency, this letter will be posted in its entirety on my blog.)

By way of clarification, you referred to me in your post as “the author, who is obviously not a trained scientist himself.” In fact, my training is in mechanical engineering and qualitative research methods. That said, does it require a trained scientist to point out the numerous flaws in the anti-feral cat/TNR literature—to, if I might borrow from the title of your post, out-science the scientists? I don’t think so. Indeed, some of your colleagues—including those you defend—have set an astonishingly low bar. Consider, for example, some of the issues I’ve addressed in my recent posts:

  • When did it become acceptable to cite work one hasn’t actually read? As I pointed out in “Lost in Translation,” this seems to be surprisingly common. Nico Dauphiné and Robert Cooper, for example, are just the latest to get William George’s classic 1974 study [1] wrong. George never “found that only about half of animals killed by cats were provided to their owners,” [2] as these two authors suggest. This is an error—and an all-too-tempting-shortcut to the doubling of predation rates—that, as Fitzgerald noted 10 years ago, “has been reported widely, though it is unfounded.” [3] (Of course, if Dauphiné and Cooper aren’t reading George’s work—which they cite—I don’t imagine they’d bother with Fitzgerald’s—which they don’t even mention.)
  • Are scientists no longer expected to recognize and deal appropriately with non-normal data sets, such as the positively skewed distributions that describe prey catches, cat ownership, time spent outdoors by pet cats, and more? As I describe in “Mean Spirited,” this seems to be the exception, not the rule. Using simple averages overestimates the factor in question, and in turn, the impact of free-roaming cats on wildlife. Such errors increase rapidly when one is multiplied by another, as Christopher Lepczyk demonstrated in his PhD work. [4]
  • While we’re on the subject of statistics, what about appropriate sample sizes? This was the focus of my 27-May post, “Sample-Minded Research.” Among the examples I discussed was Kays and DeWan’s misguided conclusion that the actual “kill rate” of pet cats allowed access to the outdoors is “3.3 times greater than the rate estimated from prey brought home.” [5] This “correction” factor has been used by many [2, 6–8] as another easy multiplier, despite the fact that it’s based on the behavior of just 24 cats—12 that returned prey home, and another 12 that were observed hunting for a total of 181 hours.Even setting aside the size of the samples, their dissimilarities are striking: the cat observed the most (46.5 hours) was only a year old—the youngest of the 12 observed, and therefore likely to be the most active hunter. In addition, larger, more comparable samples would probably have revealed a profile of time spent outdoors more similar to those found in other studies [9] and [10] (thereby reducing the magnitude of Kays and DeWan’s error).
  • And finally, there’s the issue of how some of these studies are designed. Take Cole Hawkins’ PhD work, for example. Hawkins compares rodent and bird numbers between two areas, and draws conclusions—infers important causal relationships—without (1) taking into account various factors (e.g., the many differences between the two study areas) that likely affected the differences he observed, and (2) any evidence of what “pre-treatment” conditions were like. Although he concludes, “the differences observed in this study were the results of the cat’s predatory behavior,” [11] he offers no explanation for the numerous exceptions—for example, the five (of nine) species of ground-feeding birds that showed no preference for the “no-cat area” over the area with cats. Lepcyzk, too, started off his PhD work on shaky ground, asking owners of cats to recall the number and species of birds killed or injured by their cats over the previous six-month period. Five years earlier, David Barratt demonstrated that such guesswork tends to overestimate predation rates—perhaps by a factor of two or more. [12]

In your post, you write:

“One goal of the peer review process is to assess an author’s command of the existing literature and whether or not it is being cited selectively to support the author’s views, without critical evaluation of contradictory evidence.”

But the essay you defend is plagued by such “selective support.” For example, Longcore et al. trot out figures from the long-discredited (and non-peer-reviewed, by the way) Wisconsin Study. In 1994, co-author Stanley Temple told the press that their estimates “aren’t actual data; that was just our projection to show how bad it might be.” [13] But 16 years later, Longcore et al. seem to be suggesting otherwise—that these figures are actual data. By publishing these deeply flawed estimates, the authors—and, by extension, Conservation Biology—give them undeserved credibility.

Longcore et al. also give too much weight to the claim made by Baker et al. that cat predation may produce a habitat sink, [6] ignoring strong evidence that the predation observed was compensatory rather than additive [7, 14] (as well as the significant flaws in their estimates of predation rates/levels). In this case, the contradictory evidence you refer to was provided by the authors of the original study, and still, Longcore et al. fail to acknowledge it—never mind offer any critical evaluation. Indeed, they fail to acknowledge any distinction between the two types of predation—a critical point in the discussion of cat predation and its impact on wildlife.

And what about the authors’ reference to the 2003 paper by Lepczyk et al. as evidence that “cats can play an important role in fluctuations of bird populations”? [15] One might get that impression from the paper’s abstract. However, the study’s focus was—as Lepczyk et al. note themselves—on cat predation, not bird populations:

“Although our research highlights a number of important findings regarding outdoor cats, there remains many aspects that are in need of further research… conservation biologists lack data on how specific levels of cat predation depress wildlife populations and if there are thresholds at which cat densities become a biologically significant source of mortality.” [4]

Somehow, all of this (and much more) survived the peer-review process you so revere—a system whose failures have been made quite public over the past eight months or so, first, when climate scientists’ e-mail messages were hacked at a British university, and later, when the Lancet retracted a 1998 paper incorrectly linking vaccinations to autism in children.

Obviously, these are spectacular cases. But if such high-profile work can be published and circulated widely, then how much easier is it for other papers—facing far less scrutiny—to do so as well?

Scientific Publications and the Peer-Review Process
I find your criticism ironic—even hypocritical—in light of the Scientific Societies’ Statement on the Endangered Species Act you co-authored in 2006. There, you acknowledged the value of the peer-review process, but also cautioned that “proposed limitations on the use of non-peer-reviewed technical reports and other studies will weaken, not strengthen, the science employed in endangered species decisions by limiting the data available to scientists and decision-makers.” Can we not make a similar argument for critiques and reviews such as those I’ve carefully composed and compiled via Vox Felina?

It’s curious that neither you nor the editors at Conservation Biology actually dispute any of the claims I’ve made regarding the flaws in “Critical Assessment.” Instead, you call my work “vaguely scientific” and “editorializing,” ultimately dismissing it because of its lowly status as a blog (“clearly not the place that the debate should occur”).

This is quite a departure from the position you took just four years ago. Rather than advocating for rigorous scientific discourse—regardless of a particular work’s origin—you’re now putting publication above all else. Would you suggest, for example, that using means to describe highly skewed populations—because such practice has been published in peer-reviewed journals—is appropriate and acceptable? And, further, that my calling these researchers on the carpet for it—because I’ve done it via a blog—is somehow invalid? Or that the predation rates proposed in the Wisconsin Study have merit?

The same can be said for the numerous issues I’ve covered in the past several weeks (many of which I’ve outlined above): if I’m right, then I’m right; if I’m wrong, then I’m wrong. In the end, it shouldn’t matter whether these critiques are published in a peer-reviewed journal, posted at Vox Felina, or scribbled on the back of a cocktail napkin. What matters is simply whether the points I’ve made are valid or not.

It’s difficult not to see a certain irony in your immediate and wholesale dismissal of my work—based only on the first of a four-part series (and clearly “advertised” as such). You’re quick to criticize, for example, my apparent failure to “address any of the more recent work that Longcore et al. relied on, or that have subsequently been published.” I wonder: did you bother to read any of my subsequent posts, in which I addressed these points at some length? As a trained scientist, wouldn’t you want to see all the “data” before drawing your conclusions? Your post has done far more to highlight the need for Vox Felina than to discredit it.

Don’t get me wrong—I’ve nothing against criticism; indeed, that’s the very premise of Vox Felina. But, before rendering judgment, you owe it to your readers, your colleagues, and yourself to at least have all the relevant information in front of you. This, it seems to me, is a necessary first step not only for scientific discourse, but for any civil discourse.

Los Angeles Court Case
With regard to the injunction against publicly supported TNR in Los Angeles, you’re correct in noting that the case was not about the efficacy of TNR. However, there’s far more science in the administrative record than you suggest. Though the majority of the record is made up of e-mail communications, trapping permits, and the like, it is peppered throughout with various papers, reports, and numerous references to scientific literature.

To take just one example, there’s this excerpt from a letter dated March 27, 2006 by Babak Naficy, the attorney representing the Urban Wildlands Group and the American Bird Conservancy:

“A decision by the Commission to implement the TNR policy will likely result in an increase in the population of feral cats in the City by returning feral cats to the environment that otherwise would be taken into shelters, and by issuing permits to maintain feral cat colonies. Notwithstanding the goal of the project to reduce feral cat numbers, TNR programs are less effective than removal in controlling feral cat populations, [16] and consequently this shift in policy would increase the number of feral cats in the environment. As has been communicated to the Commission by my clients in the past, it is well settled that feral and domestic cats adversely affect the population of songbirds and other small animals, such as small mammals and lizards. [11] Furthermore, the scientific literature shows that TNR is not effective in decreasing the number of feral cats on a regional basis. [17] An intensive TNR program combined with cat adoption at a Florida university took 11 years to reduce a county by two-thirds (6% per year), and even then animals continued to be abandoned and added to the colony.” [18]

“Additionally, City-endorsed feral cat colonies present a severe public health risk, [19] especially to vulnerable human populations such as the homeless. Maternal exposure to toxoplasmosis, often carried by feral cats, increases risk of schizophrenia in humans. [20] Therefore, any decision that mandates return of unowned cats to the environment may increase the number of free-roaming cats in the City and will likely result in a concomitant adverse impact on the environment.”

That said, perhaps I was not clear in my post. I was not implying any direct connection between the Longcore et al. paper and the Los Angeles TNR case (e.g., that the paper itself was part of the administrative record). The point I was trying to make was that the Urban Wildlands Group—lead petitioner in the case—was not a disinterested party concerned with science for its own sake. Longcore et al. were key stakeholders—focused, it seems, more on their “message” (the timing of which was itself uncanny) than the validity of any scientific claims.

And in any event, I don’t see how the case can be so easily divorced from science. This is not about property rights or tax code. Its status as a California Environmental Quality Act (CEQA) case presupposes the possibility of “either a direct physical change in the environment or a reasonably foreseeable indirect change in the environment.” The evidence of such changes, of course, would rely on scientific research. As I say, the administrative record contains numerous claims regarding potential impacts and the studies supporting or refuting them. Whether the judge in the case allowed this material to influence his eventual decision is unknown; but it’s clear from court transcripts that he considered it quite relevant:

“Look, you put feral cats in the wild, they endanger wildlife. That is an environmental concern…”

“It doesn’t affect birds? It doesn’t affect other wildlife? A fair argument has been made that it does. A fair argument… a fair argument has been made that when you take them out of the wild—not all of them are taken out of wild—but you take 50,000 cats out of the wild and do not consider other alternatives such as euthanizing them and return them back to the wild, I would be embarrassed to stand there and argue that there is no environmental effect… so you bring them in, you neuter the them and you put them out, and they endanger other wildlife and perhaps health and a lot of other issues that come to bear, and that’s the only consideration made and that’s not a project. Please, spare me.”

“And who is to go out and if the feral cats are running wild, does the Animal Services have a program to round up a herd of cats, if that’s possible—that’s an old expression—and bring them in a neuter them and let these little kitties out to kill birds and other wildlife?”

Whether or not Los Angeles had an official TNR program in place may have been at the center of the case, but it was certainly not the whole case.

Compromise, Courage, and Leadership
As I’ve noted on Vox Felina’s About page, there are legitimate issues to be debated regarding the efficacy, environmental impact, and morality of TNR. But attempts at an honest, productive debate are hampered—if not derailed entirely—by the dubious claims so often put forward by TNR opponents. Exactly the sort of claims I’ve attempted to untangle over the past several weeks.

But from what I’ve read of your work, you don’t seem interested in such a debate, and even less interested in finding common ground:

“Cooperation and compromise, no matter what the cost, is not courageous leadership.” [21]

Perhaps it’s impressive as rhetoric, but your comments strike me as somewhat hypocritical (your attempt to make a virtue of the same ideological inflexibility you dismiss in the animal rights community), misguided, and, in the end, simply unhelpful. More worrisome, however, is your willingness to let your ideology blind you to the numerous errors in the work you so vigorously defend.

Michael, how can you expect so much courage and leadership from your colleagues when you demand so little honesty and integrity?

Peter J. Wolf
www.voxfelina.com

Literature Cited
1. George, W., “Domestic cats as predators and factors in winter shortages of raptor prey.” The Wilson Bulletin. 1974. 86(4): p. 384–396.

2. Dauphiné, N. and Cooper, R.J., Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations, in Fourth International Partners in Flight Conference: Tundra to Tropics. 2009. p. 205–219.

3. Fitzgerald, B.M. and Turner, D.C., Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press: Cambridge, U.K.; New York. p. 151–175.

4. Lepczyk, C.A., Mertig, A.G., and Liu, J., “Landowners and cat predation across rural-to-urban landscapes.” Biological Conservation. 2003. 115(2): p. 191-201.

5. Kays, R.W. and DeWan, A.A., “Ecological impact of inside/outside house cats around a suburban nature preserve.” Animal Conservation. 2004. 7(3): p. 273-283.

6. Baker, P.J., et al., “Impact of predation by domestic cats Felis catus in an urban area.” Mammal Review. 2005. 35(3/4): p. 302-312.

7. Baker, P.J., et al., “Cats about town: is predation by free-ranging pet cats Felis catus likely to affect urban bird populations? Ibis. 2008. 150: p. 86-99.

8. van Heezik, Y., et al., “Do domestic cats impose an unsustainable harvest on urban bird populations? Biological Conservation. 143(1): p. 121-130.

9. ABC, Human Attitudes and Behavior Regarding Cats. 1997, American Bird Conservancy: Washington, DC. http://www.abcbirds.org/abcprograms/policy/cats/materials/attitude.pdf

10. 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.

11. Hawkins, C.C., Impact of a subsidized exotic predator on native biota: Effect of house cats (Felis catus) on California birds and rodents. 1998, Texas A&M University

12. Barratt, D.G., “Predation by house cats, Felis catus (L.), in Canberra, Australia. II. Factors affecting the amount of prey caught and estimates of the impact on wildlife.” Wildlife Research. 1998. 25(5): p. 475–487.

13. Elliott, J., The Accused, in The Sonoma County Independent. 1994. p. 1, 10

14. Møller, A.P. and Erritzøe, J., “Predation against birds with low immunocompetence.” Oecologia. 2000. 122(4): p. 500-504.

15. Longcore, T., Rich, C., and Sullivan, L.M., “Critical Assessment of Claims Regarding Management of Feral Cats by Trap–Neuter–Return.” Conservation Biology. 2009. 23(4): p. 887–894.

16. Andersen, M.C., Martin, B.J., and Roemer, G.W., “Use of matrix population models to estimate the efficacy of euthanasia versus trap-neuter-return for management of free-roaming cats.” Journal of the American Veterinary Medical Association. 2004. 225(12): p. 1871-1876.

17. Foley, P., et al., “Analysis of the impact of trap-neuter-return programs on populations of feral cats.” Journal of the American Veterinary Medical Association. 2005. 227(11): p. 1775-1781.

18. Levy, J.K., Gale, D.W., and Gale, L.A., “Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population.” Journal of the American Veterinary Medical Association. 2003. 222(1): p. 42-46.

19. Patronek, G.J., “Free-roaming and feral cats—their impact on wildlife and human beings.” Journal of the American Veterinary Medical Association. 1998. 212(2): p. 218–226.

20. Brown, A.S., et al., “Maternal Exposure to Toxoplasmosis and Risk of Schizophrenia in Adult Offspring.” Am J Psychiatry. 2005. 162(4): p. 767-773.

21. Hutchins, M., “Animal Rights and Conservation.” Conservation Biology. 2008. 22(4): p. 815–816.

The Work Speaks—Part 6: Pain by Numbers

In April, Conservation Biology published a comment authored by Christopher A. Lepczyk, Nico Dauphiné, David M. Bird, Sheila Conant, Robert J. Cooper, David C. Duffy, Pamela Jo Hatley, Peter P. Marra, Elizabeth Stone, and Stanley A. Temple. In it, the authors “applaud the recent essay by Longcore et al. (2009) in raising the awareness about trap-neuter-return (TNR) to the conservation community,” [1] and puzzle at the lack of TNR opposition among the larger scientific community:

“…it may be that conservation biologists and wildlife ecologists believe the issue of feral cats has already been studied enough and that the work speaks for itself, suggesting that no further research is needed.”

In fact, “the work”—taken as a whole—is neither as rigorous nor as conclusive as Lepczyk et al. suggest. And far too much of it is plagued by exaggeration, misrepresentations, errors, and obvious bias. In Part 5 of this series, I critiqued Cole Hawkins’ 1998 PhD dissertation. Here, I’m going to untangle some of Lepczyk’s own PhD work: Landowners and cat predation across rural-to-urban landscapes, published in 2003.

The Study
In this study, surveys were distributed across three southeastern Michigan landscapes (rural, suburban, and urban) corresponding to established breeding bird survey (BBS) routes. [2] Among the survey questions:

“If you or members of your household own cats that are allowed access to the outside, approximately how many dead or injured birds a week do all the cats bring in during the spring and summer months (April through August) (0, 1, 2–3, 4–5, 6–7, 8–9, 10–15, 16–20, more than 20)?”

Based on 968 surveys returned from 1654 private landowners (a decent response rate of 58.5%), Lepczyk et al. conclude:

“Across the three landscapes there were ~800 to ~3100 cats, which kill between ~16,000 and ~47,000 birds during the breeding season, resulting in a minimum of ~1 bird killed/km/day.”

Increasing Uncertainty
How do Lepczyk and his collaborators arrive at these figures? It’s not entirely clear, actually. Despite numerous attempts, I’ve been unable to follow all of their calculations. However, using their data, I developed my own estimate: 1,119 outdoor cats, 511 of which were reported to be successful hunters.

Using this figure, I then summed across all three landscapes the birds killed or injured, plus those killed or injured by non-respondents’ hunting cats (based on the ratio of hunters to outdoor cats owned by respondents, or about 50%). The resulting estimate is 15,856 birds killed over the 22-week breeding season—close to the low estimate suggested by Lepczyk et al., but just a third of their maximum.

So, why the discrepancy?

One reason is that, at least for some of their estimates, Lepczyk et al. assumed that every landowner who didn’t respond to the survey owned outdoor cats. This, despite their survey results, which indicated that only about one-third of landowners fell into this category.

But the authors go further, generating predation estimates based on pure speculation, specifically that “non-respondents have 150% the number of outdoor cats as respondents.” [2] It should be noted that Lepczyk et al. also ran another scenario in which non-respondents had half the outdoor cats as did respondents—but, again, in both cases they assume that every non-respondent owned outdoor cats.

As a result of this approach, the authors end up in some strange territory: the estimated number of cats owned by non-respondents (based on the assumptions described above) far exceeds the number owned by respondents—by more than a two-to-one margin, in some cases. If the greatest impacts are going to be attributable to non-respondents, then what’s the point of doing the survey in the first place? There are accepted methods by which one can manage uncertainty—statistical analysis, confidence intervals, and the like. What Lepczyk et al. have done serves just one purpose: to inflate apparent predation rates.

Skewed Distributions
In addition to the flaws described above, there are some fundamental errors in the way the authors handle their data. Like so many others, Lepczyk et al. ignore the fact that their data is not normally distributed:

  1. Lepczyk et al. use the average number of birds killed/cat to calculate the total number of bids killed for each of the three landscapes. As I discussed previously), this is a highly positively skewed distribution—using a simple average, therefore, greatly overestimates the cats’ impact (by as much as a factor of two).
  2. A similar error is made when the authors use an average to describe the number of outdoor cats owned by each landowner. Again, because this is a skewed distribution, their use of a simple average exaggerates the extent of predation.
  3. The two inflated figures described in (1) and (2) are multiplied together, further inflating estimated predation rates.

Barratt has suggested that “median numbers of prey estimated or observed to be caught per year are approximately half the mean values, and are a better representation of the average predation by house cats based on these data.” [3] Accounting for the first point alone, then, my estimate is reduced to 8,000 birds killed over the 22-week breeding season.

Accounting for the second point is somewhat trickier. For one thing, we don’t know what constitutes an outdoor cat here—the survey simply asked respondents if they owned cats “that are allowed access to the outdoors.” [2] However, we do know the results of a 2003 survey, which indicated that nearly half of the cats with outdoor access were outside for two or fewer hours a day. And 29% were outdoors for less than an hour each day. [4] Although these figures almost certainly reflect owners in urban and suburban landscapes more than those in rural landscapes, it’s clear that a simple yes-or-no question on the subject is insufficient. Indeed, such a question will invariably overestimate the number of “outdoor cats”—which in turn overestimates predation rates.

This, coupled with the error inherent in using a simple average, pushes predation estimates lower. And the third point reduces those estimates further still. Taken together, these corrections could put my estimate closer to 4,000 birds. More important, the upper estimate proposed by Lepczyk et al.—47,000 birds—could easily be 10 times too high.

The Small Print
Despite their inflated figures, Lepczyk et al. suggest—rather absurdly, in light of the substantial flaws described above—that perhaps their estimates are actually too conservative:

“One caveat to our study is that landowners may have underestimated the number of cats they allow access to the outside. Such a result was found in a similar study of landowners in Wisconsin (Coleman and Temple, 1993).” [1] (Note: After reviewing “Rural Residents’ Free-Ranging Domestic Cats: A Survey,” [5] I’ve found no evidence of such a result.)

“… we found that a very common volunteered response among landowners that had no outdoor cats was that either their neighbors owned outdoor cats or that feral cats were present in the vicinity of their land… [suggesting] that at least some landowners under reported or chose not to report the number of outdoor cats they owned.”

But what about their reports of birds brought home killed or injured—how trustworthy were those? After all, the survey (mailed during the first week of October) asked respondents to recall the number of birds their cat(s) brought home April through August. Surely, there was a lot of guesswork involved. In fact, David Barratt found this kind of guesswork to overestimate predation rates. In a study published five years prior to “Landowners and Cat Predation,” Barratt concluded, “predicted rates of predation greater than about ten prey per year generally over-estimated predation observed.” [3]

The two studies cannot be compared directly for a number of reasons, but by way of comparison, the average predation rate used by Lepczyk et al. is approximately 31 birds/cat for the 22-week breeding season. Using Barratt’s work, in which the “heaviest” six continuous months correspond to about 58% of yearly prey totals, [6] I converted this to a yearly rate of 53 birds/cat/year. Barratt has shown that the actual predation rate, at this level, is less than half the rate predicted by cat owners. In other words, predictions of 50 birds/year generally correspond to catches closer to 25 birds/year.

While Lepczyk et al. emphasize the potential for under-estimating predation levels, they never consider the risk of over-estimating these levels—or their most obvious potential source of error: landowners’ recollections of birds killed. The authors question respondents’ reports of outdoor cats, but accept without question their reports of birds injured or killed over the previous six-month period. And, as Barratt indicated, such reports can be inflated by a factor of two or more!

Something else I find troubling comes, of all places, from the Acknowledgements section. Among those thanked “for helpful and constructive reviews” are American Bird Conservancy (ABC) president George Fenwick and Linda Winter, director of ABC’s Cats Indoors! campaign. It’s not clear how Fenwick and Winter contributed to the final paper, but their involvement on any level raises questions about possible bias. Certainly, Winter has credibility issues when it comes to “research” about the impact of free-roaming cats on birds, as I’ve already described (see also pp. 18–24 of TNR Past present and future: A history of the trap-neuter-return movement [7]).

*     *     *

The same year Lepczyk’s paper was published, the American Veterinary Medicine Association held an Animal Welfare Forum “devoted to the management of abandoned and feral cats.” [8] In attendance were more than 200 veterinarians, animal control officials, wildlife conservationists, and animal advocates—each with a different perspective on feral cats in general and TNR in particular.

In welcoming this diverse group, then-President-Elect Bonnie Beaver recognized the range of contentious issues before them:

“Feral cats evoke hot debates about ecological issues, individual cat welfare, human responsibilities, intercat disease transmission, humaneness, zoonosis control, and management and dissolution of unowned cats.” [8]

Amidst the “hot debate,” though, Beaver was optimistic:

“We will not always agree, but we will come away with increased knowledge and a renewed commitment to work for the welfare of all the animals with which we share the earth” [8]

While I tend to share Beaver’s optimism, I think the debate is hurt—if not derailed entirely—by the publication of research aimed not at increasing our collective knowledge, but rather at supporting a particular position. Like Cole Hawkins’ dissertation, “Landowners and Cat Predation” is, at best, an interesting pilot study for subsequent work. And yet, it’s widely—and uncritically—cited in the feral cat/TNR literature. Longcore et al., for example, refer to it as “evidence [indicating] that cats can play an important role in fluctuations of bird populations,” [9] despite the fact that Lepczyk et al. don’t actually address the issue of bird populations at all. More recently, Dauphiné and Cooper use the inflated predation rate suggested by Lepczyk et al. (along with rates proposed by other researchers) to arrive at their “billion birds” figure. [10]

The method employed in “Landowners and Cat Predation”—asking owners of cats to recall the number and species of birds over the previous six-month period—invites overestimation from the very outset. Lepczyk et al. then inflate these numbers through both careless (e.g., using averages to describe skewed data) and deliberate (e.g., assuming all non-respondents owned cats—perhaps 50% more than respondents did) means. Rather than getting us any closer to the truth about cat predation, this study only obscured it further.

Worse, it’s been packaged and sold—and subsequently “bought”—as rigorous science, thereby giving it an undeserved legitimacy. Such efforts are impediments to knowledge and understanding—and therefore, to progress.

References
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627-629.

2. Lepczyk, C.A., Mertig, A.G., and Liu, J., “Landowners and cat predation across rural-to-urban landscapes.” Biological Conservation. 2003. 115(2): p. 191-201.

3. Barratt, D.G., “Predation by house cats, Felis catus (L.), in Canberra, Australia. II. Factors affecting the amount of prey caught and estimates of the impact on wildlife.” Wildlife Research. 1998. 25(5): p. 475–487.

4. 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.

5. Coleman, J.S. and Temple, S.A., “Rural Residents’ Free-Ranging Domestic Cats: A Survey.” Wildlife Society Bulletin. 1993. 21(4): p. 381–390.

6. Barratt, D.G., “Predation by House Cats, Felis catus (L.), in Canberra, Australia. I. Prey Composition and Preference.” Wildlife Research. 1997. 24(3): p. 263–277.

7. Berkeley, E.P., TNR Past present and future: A history of the trap-neuter-return movement. 2004, Bethesda, MD: Alley Cat Allies.

8. Kuehn, B.M. and Kahler, S.C. The Cat Debate. JAVMA Online 2004 November 27, 2009 [accessed 2009 December 24].  http://www.avma.org/onlnews/javma/jan04/040115a.asp.

9. Longcore, T., Rich, C., and Sullivan, L.M., “Critical Assessment of Claims Regarding Management of Feral Cats by Trap–Neuter–Return.” Conservation Biology. 2009. 23(4): p. 887–894.

10. Dauphiné, N. and Cooper, R.J., Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations, in Fourth International Partners in Flight Conference: Tundra to Tropics. 2010. p. 205–219.

The Work Speaks—Part 2: Sample-Minded Research

In April, Conservation Biology published a comment authored by Christopher A. Lepczyk, Nico Dauphiné, David M. Bird, Sheila Conant, Robert J. Cooper, David C. Duffy, Pamela Jo Hatley, Peter P. Marra, Elizabeth Stone, and Stanley A. Temple. In it, the authors “applaud the recent essay by Longcore et al. (2009) in raising the awareness about trap-neuter-return (TNR) to the conservation community,” [1] and puzzle at the lack of TNR opposition among the larger scientific community:

“…it may be that conservation biologists and wildlife ecologists believe the issue of feral cats has already been studied enough and that the work speaks for itself, suggesting that no further research is needed.”

In fact, “the work”—taken as a whole—is neither as rigorous nor as conclusive as Lepczyk et al. suggest. And far too much of it is plagued by exaggeration, misrepresentations, errors, and obvious bias. In my previous post, I presented examples of researchers “reinterpreting” the work of others to better fit their own arguments. For the next few posts, I’ll focus on some of the major flaws in the feral cat/TNR research itself—beginning with the reliance, by some, on small sample sizes.

Size Does Matter
There are all kinds of reasons for small sample sizes, perhaps the most common being limited resources (e.g., time, funding, etc.). And they are often a fact of life in real-world research, where investigators have less control over conditions than they might in a laboratory environment. Studies employing small sample sizes are not without value; indeed, they often serve as useful pilot studies for future, more comprehensive, work. They do become problematic, though, when broad conclusions are drawn from their results. Below are three (among many!) examples of such studies.

Impressive Estimates
In “Free-Ranging Domestic Cat Predation on Native Vertebrates in Rural and Urban Virginia,” [2] published in 1992, the authors estimated that the state’s 1,048,704 cats were killing between 3,146,112 and 26,217,600 songbirds each year. “This number,” they note, “is certainly inaccurate to some degree, although the estimates are impressive.” [2] Impressive? I suppose. Maybe incredible is more fitting—since the study from which they were derived included exactly five cats, four “urban” and one “rural.”

Mitchell and Beck acknowledged “the limitations of extrapolation to large areas from relatively small data sets such as ours,” suggesting that their work was intended to provoke future “careful and detailed studies that can reveal truer estimates of the impact of this introduced species.” Hawkins [3] and Dauphiné and Cooper [4], however, seem to take them at their word, regardless of any disclaimers.

Many Cats, Multiple Seasons
In a recent study on Catalina Island, the researchers “examined the home-range behavior and movements of sterilized and intact radiocollared feral cats living in the interior” [5] of the island. Although Guttilla and Stapp concede that “sample sizes, especially for males, were relatively low” despite having “tracked many cats across multiple seasons,” they nevertheless come to some rather dramatic conclusions. Among them: “sterilization likely would not reduce the impact of feral cats on native prey.” [5]

So what do the authors mean by many and multiple? Actually, there were just 27 cats in the study (of an estimated 614–732 on the island). “Four cats were tracked during all four seasons, 9 cats were tracked for three consecutive seasons, 4 cats were tracked for 2 consecutive seasons, and the remaining cats were tracked for 1 season.” [5] And these numbers were effectively cut in half, because the researchers were comparing sterilized and non-sterilized cats. At best, this is a pilot study—though it’s already morphed into something more substantial in the mainstream media.

Myth vs. Math
In their 2004 study, “Ecological Impact of Inside/Outside House Cats Around a Suburban Nature Preserve,” Kays and DeWan observed hunting cats, concluding that their kill rate (13%) is “3.3 times greater than the rate estimated from prey brought home.” [6] Not surprisingly, this figure has been used as an instant multiplier (much in the same way William George’s work has been misused) for researchers interested in “correcting” (inflating?) prey numbers. [4, 7-11]

But this ratio, 3.3, hinges on the hunting behaviors of just 24 cats—12 that returned prey home, and another 12 (11 pets and 1 feral) that were observed hunting for a total of 181 hours (anywhere from 4.8–46.5 hours per cat). It’s interesting to note that the cat observed the most (46.5 hours) was only a year old—the youngest of the 12 observed, and likely the most active hunter. This factor alone could have had a significant influence on the outcome of the study.

Also, as several studies have shown [7,8,12,13], the distribution of prey catches tends to be highly skewed (many cats catch few/no prey, while a few catch a lot). In other words, the distribution is not the familiar bell curve at all—making it inappropriate to use a simple average for calculating estimations (a topic I’ll address in detail later). What’s more, with only 12 cats being monitored, how can we be sure their behaviors accurately represent any real distribution at all?

But the key to their calculation is the average time spent outdoors. This, too, tends to be a highly skewed distribution [14, 15], although—curiously—Kays and DeWan’s data suggest otherwise. By way of example, a 2003 survey conducted by Clancy, Moore, and Bertone [15] revealed that nearly half of the cats with outdoor access were outside for two or fewer hours a day. And 29% were outdoors for less than an hour each day. A survey conducted by the American Bird Conservancy revealed similar behavior, reporting that “35% keep their cats indoors all of the time” and “31% keep them indoors mostly with some outside access.” [14]

Kays and DeWan’s average of 8.35 hours/day, then, seems rather out of line with other studies. This, in addition to a number of unknowns (e.g., influence of time of day/night on hunting success, actual time spent hunting by each cat, etc.) raises serious questions about their conclusions.

By way of comparison, using an average of 2.5 hours/day (which is not out of line with the surveys described above) would yield a ratio of 1:1. In other words, no difference between predation rates predicted by actual hunting observation and those predicted by way of prey returned home. Which is not to say that I agree with Kays and DeWan’s underlying methods—we don’t know the possible effects of seasonal variation, for example, or differences in habitat. I’m only pointing out how sensitive this one factor—with its enormous consequences—is to the amount of time cats actually spend outdoors (and, just to introduce one more complication: I’d be very surprised if the amount of outdoor time cats spend hunting is normally distributed; it, too, is probably skewed).

Ironically, while the authors express disappointment that “biologists have rarely sampled both cat and prey populations in such a way that direct effects on prey populations can be shown,” [6] they seem to have had no misgivings about how their work—suffering from its own sampling issues—might be used to misrepresent those same effects.

*     *     *

Next, I’ll discuss the difference between compensatory and additive predation, and how that affects predictions of feral cat impacts on wildlife.

References
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627-629.

2. Mitchell, J.C. and Beck, R.A., “Free-Ranging Domestic Cat Predation on Native Vertebrates in Rural and Urban Virginia.” Virginia Journal of Science. 1992. 43(1B): p. 197–207.

3. Hawkins, C.C., Impact of a subsidized exotic predator on native biota: Effect of house cats (Felis catus) on California birds and rodents. 1998. PhD Dissertation, Texas A&M University.

4. Dauphiné, N. and Cooper, R.J., Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations, in Fourth International Partners in Flight Conference: Tundra to Tropics. 2010. p. 205–219

5. Guttilla, D.A. and Stapp, P., “Effects of sterilization on movements of feral cats at a wildland-urban interface.” Journal of Mammalogy. 2010. 91(2): p. 482-489.

6. Kays, R.W. and DeWan, A.A., “Ecological impact of inside/outside house cats around a suburban nature preserve.” Animal Conservation. 2004. 7(3): p. 273-283.

7. Baker, P.J., et al., “Impact of predation by domestic cats Felis catus in an urban area.” Mammal Review. 2005. 35(3/4): p. 302-312.

8. Baker, P.J., et al., “Cats about town: is predation by free-ranging pet cats Felis catus likely to affect urban bird populations? Ibis. 2008. 150: p. 86-99.

9. van Heezik, Y., et al., “Do domestic cats impose an unsustainable harvest on urban bird populations? Biological Conservation. 143(1): p. 121-130.

10. Nelson, S.H., Evans, A.D., and Bradbury, R.B., “The efficacy of collar-mounted devices in reducing the rate of predation of wildlife by domestic cats.” Applied Animal Behaviour Science. 2005. 94(3-4): p. 273-285.

11. MacLean, M.M., et al., “The usefulness of sensitivity analysis for predicting the effects of cat predation on the population dynamics of their avian prey.” Ibis. 2008. 150(Suppl. 1): p. 100-113.

12. Churcher, P.B. and Lawton, J.H., “Predation by domestic cats in an English village.” Journal of Zoology. 1987. 212(3): p. 439-455.

13. Woods, M., McDonald, R.A., and Harris, S., “Predation of wildlife by domestic cats Felis catus in Great Britain.” Mammal Review. 2003. 33(2): p. 174-188.

14.  ABC, Human Attitudes and Behavior Regarding Cats. 1997, American Bird Conservancy: Washington, DC. http://www.abcbirds.org/abcprograms/policy/cats/materials/attitude.pdf

15. 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.

The Work Speaks—Part 1: Lost in Translation

In April, Conservation Biology published a comment authored by Christopher A. Lepczyk, Nico Dauphiné, David M. Bird, Sheila Conant, Robert J. Cooper, David C. Duffy, Pamela Jo Hatley, Peter P. Marra, Elizabeth Stone, and Stanley A. Temple. In it, the authors “applaud the recent essay by Longcore et al. (2009) in raising the awareness about trap-neuter-return (TNR) to the conservation community,” [1] and puzzle at the lack of TNR opposition among the larger scientific community:

“…it may be that conservation biologists and wildlife ecologists believe the issue of feral cats has already been studied enough and that the work speaks for itself, suggesting that no further research is needed.”

In fact, “the work”—taken as a whole—is neither as rigorous nor as conclusive as Lepczyk et al. suggest. And far too much of it is plagued by exaggerations, misrepresentations, errors, and obvious bias. For the next few posts, I’m going to present a sampling of its more serious flaws, beginning with how some researchers “reinterpret” work of others to suit their own purposes.

Tell It Like It Is
Studies of cat predation frequently cite the work of William G. George, who, in 1974, published a paper documenting his meticulous observations of the hunting behavior of three cats on his southern Illinois farm. “The results,” wrote George, “established a basis for examining the possibility that cat predation may result in depleted winter populations of microtine rodents and other prey of Red-tailed Hawks, Marsh Hawks, and American Kestrels.” [2]

Thirty years later, David A. Jessup interpreted things rather differently, giving George’s work an additional—and unwarranted—degree of certainty. Gone are the doubts that George expressed—first, regarding the impact of cat predation on rodent and other prey populations; second, regarding the relationship between these populations and the raptors that feed on them. For Jessup—who offers no additional evidence—it’s all very straightforward: “Feral cats also indirectly kill native predators by removing their food base.” [3]

More recently, Guttilla and Stapp seem to prefer Jessup’s take: “Human-subsidized cats… can spill over into less densely populated wildland areas where they reduce prey for native predators (George 1974).” [4]

If any additional work has been done on the subject (surely there are more cats in the area these days; how are the voles and raptors faring?), it seems to have gone unnoticed. Instead, Jessup, Guttilla, and Stapp (and others, too, no doubt) have simply rewritten George’s conclusion to suit their own purposes. Perhaps their version makes for a better story, but it’s rather poor science.

Credit Where Little/None Is Due
When the Lancet recently retracted a 1998 paper linking vaccinations to autism in children—“research” that sparked the ongoing backlash against vaccinations—it was headline news. The move prompted this criticism from one member of the British Parliament: “The Lancet article should never have been published, and its peer review system failed. The article should now be expunged from the academic record…”

At the risk of drawing too many parallels between the two papers, I think the same can be said for Coleman and Temple’s infamous “Wisconsin Study.” (On the other hand, it does serve a useful purpose as a red flag.) Actually, as Goldstein et al. point out, Coleman and Temple’s paper was never peer-reviewed (not necessarily a deal-breaker in my book, but such publications do warrant additional scrutiny), but achieved its mythical status by being cited ad nauseam in peer-reviewed journals, as well as the mainstream media.

Does anybody actually believe the numbers suggested by Coleman and Temple? Stanley Temple (one of the co-authors of the recent anti-feral cat/TNR comment in Conservation Biology) himself admitted their published figures “aren’t actual data; that was just our projection to show how bad it might be.” [5]

I don’t think Longcore et al. [6] or the editors at Conservation Biology put much stock in the Wisconsin Study—so why continue to publish “projections” that have been so thoroughly discredited? Because doing so strengthens their case, at least among those who don’t know any better—especially people outside the scientific community, including many journalists, policy makers, judges, and the general public.

In their recent comment, Lepczyk et al. suggest that conservation biologists and wildlife ecologists “look to the evolutionary biology community” [1] for an example of how to influence policy:

“When local policies or regulations are put forth that promote the teaching of creationism or intelligent design, the evolutionary biologists have responded in force from across the nation and world.” [1]

Let’s set aside for the moment all the baggage associated with their analogy. My question is this: Is the evolutionary biology community still publishing bogus “projections” from 13 years ago? I doubt it.

Check Your Premises
In their recent paper (available for download via the American Bird Conservancy (ABC) website), Dauphiné and Cooper arrive at their absurd figure of “117–157 million free-ranging cats in the United States,” [7] in part, by way of Jessup’s “estimated 60 to 100 million feral and abandoned cats in the United States.” [3]

So where does Jessup’s figure come from? We have no idea—there’s no citation. And Jessup is no authority on the subject—having conducted no studies or reviews of studies that quantify the feral cat population. What’s more, his “estimation” is among the highest figures published. Yet this is the shaky foundation upon which Dauphiné and Cooper attempt to build their subsequent argument.

The authors then add to the (dubious) number of feral cats the proportion of pet cats allowed outdoors. They refer to a 2004 paper by Linda Winter, director of ABC’s Cats Indoors! campaign, in which it was reported, “A 1997 nationwide random telephone survey indicated that 66% of cat owners let their cats outdoors some or all of the time.” [8]

That’s an interesting way to put it—Winter makes it sound like two-thirds of pet cats are essentially outdoor cats. But the surveycommissioned by ABC!—actually indicates that “35% keep their cats indoors all of the time” and “31% keep them indoors mostly with some outside access.” [9] The difference in wording is subtle, and hampered by imprecision—it all comes down to the meaning of some.

Winter’s 2004 paper implies that there are twice as many outdoor pet cats as was indicated in the original survey—an interpretation Dauphiné and Cooper seem to embrace. Had they looked further—and to a less biased source—they might have been able to get a better handle on the degree of outdoor access. For example: a 2003 survey conducted by Clancy, Moore, and Bertone [10] revealing that nearly half of the cats with outdoor access were outside for two or fewer hours a day. And 29% were outdoors for less than an hour each day.

Do these “part-timers” have the same impact on wildlife as feral cats? Dauphiné and Cooper would have us believe they do.

[Note: For a closer look at the flaws in Dauphiné and Cooper’s paper, download “One Billion Birds,” by Laurie D. Goldstein.]

The lesson? Credible research begins with a solid foundation; a weak foundation—one plagued with unsubstantiated claims—on the other hand, leads to pseudoscience.

Or worse. ABC’s Senior Policy Advisor, Steve Holmer, cited Dauphiné and Cooper’s bogus numbers when he spoke to the Los Angeles Times about his organization’s involvement with the legal battle against TNR. It’s like the Wisconsin Study all over again.

When All Else Fails, Look It Up
Though this would seem to be utterly obvious, it apparently bears repeating: Don’t cite work you haven’t actually read.

Isn’t this emphasized in all graduate (indeed, undergraduate, too) programs? What grad student isn’t, at one time or another, tempted to take the easy way out—ride the coattails of somebody else who’s (presumably) done the real work? In addition to the ethical implications, such shortcuts tend to invite more immediate troubles, too. Again, George’s work (described above) provides an excellent case study. Below are some examples of how his work has been referenced in the cat predation literature:

“It is very unlikely that cats bring home all of the prey that they capture. What proportion they bring home has been little studied. George (1974) on a farm in Illinois USA found that three house cats, all adequately fed, brought home about 50% of the prey that they killed.” [11]

“George found that about 50% of prey were indeed brought home, with the other 50% being eaten, scavenged by other animals or simply not found.” [12]

“These approximations are probably underestimates, assuming that cats do not bring back all the prey that they kill.” [13]

Trouble is, George never said these things; what he said was:

“… the cats never ate or deposited prey where caught but instead carried it into a ‘delivery area,’ consisting of the house and lawn. The exclusive use of this delivery area was verified in 18 to 70 mammal captures per cat, as witnessed between early 1967 and 1971.” [2]

In 2000, Fitzgerald and Turner pointed out the fact that George’s work was being misrepresented, noting that the erroneous 50% figure “has been reported widely, though it is unfounded.” [14] Nevertheless, the myth persists—even in 2010.

“In Illinois, George (1974) found that only about half of animals killed by cats were provided to their owners, and in upstate New York, Kays and DeWan (2004) found that observed cat predation rates were 3.3 times higher than predation rates measured through prey returns to owners. Thus, predation rates measured through prey returns may represent one half to less than one third of what pet cats actually kill…” [7]

As Dauphiné and Cooper demonstrate, the “reinterpreted” version of George’s work makes for a very convenient multiplier—suddenly, every kill reported is doubled (or tripled, if Kays and DeWan are to be believed—and they’re not, but that’s a topic for another post). Never mind the fact that it has no basis in actual fact.

Getting a copy of George’s study isn’t difficult, especially with the inter-library loan services available today. To reference it—to use George’s work so that your own appears more credible—without ever having actually read it, is simply inexcusable. But citing it blindly suggests more than laziness—it points to a certain coziness that has no place in scientific discourse. Too much Kool-Aid drinking, and not enough honest research.

*     *     *

Scientists can (and do) look at identical results and come to very different conclusions. But misinterpreting, misrepresenting, or dismissing the conclusions of others, is something else altogether. As the above examples (and there are many, many more!) illustrate, this happens far too often in the feral cat/TNR literature. And if we can’t believe what researchers are saying about the work of others, why would we believe what they say about their own work?

Next, I’ll focus on some of the major flaws in the feral cat/TNR literature—beginning with small sample sizes

References
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627-629.

2. George, W., “Domestic cats as predators and factors in winter shortages of raptor prey.” The Wilson Bulletin. 1974. 86(4): p. 384–396.

3. Jessup, D.A., “The welfare of feral cats and wildlife.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1377-1383.

4. Guttilla, D.A. and Stapp, P., “Effects of sterilization on movements of feral cats at a wildland-urban interface.” Journal of Mammalogy. 2010. 91(2): p. 482-489.

5. Elliott, J., The Accused, in The Sonoma County Independent. 1994. p. 1, 10

6. Longcore, T., Rich, C., and Sullivan, L.M., “Critical Assessment of Claims Regarding Management of Feral Cats by Trap–Neuter–Return.” Conservation Biology. 2009. 23(4): p. 887–894.

7. Dauphiné, N. and Cooper, R.J., Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations, in Fourth International Partners in Flight Conference: Tundra to Tropics. 2010. p. 205–219

8. Winter, L., “Trap-neuter-release programs: the reality and the impacts.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1369-1376.

9. ABC, Human Attitudes and Behavior Regarding Cats. 1997, American Bird Conservancy: Washington, DC. http://www.abcbirds.org/abcprograms/policy/cats/materials/attitude.pdf

10. 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.

11. Churcher, P.B. and Lawton, J.H., “Predation by domestic cats in an English village.” Journal of Zoology. 1987. 212(3): p. 439-455.

12. May, R.M., “Control of feline delinquency.” Nature. 1988. 332(March): p. 392-393.

13. Crooks, K.R. and Soule, M.E., “Mesopredator release and avifaunal extinctions in a fragmented system.” Nature. 1999. 400(6744): p. 563.

14. Fitzgerald, B.M. and Turner, D.C., Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press: Cambridge, U.K.; New York. p. 151–175.

Hold Your Applause

Three months after my letter to Conservation Biology was rejected, it’s become apparent what they were really looking for: applause, not criticism.

Of course it probably doesn’t help that I’m not a member of the club; I don’t even know the secret handshake. (Michael Hutchins, writing for the Wildlife Society Blog, “Making Tracks,” has accused me—an outsider—of trying to “out-science the scientists.”)

In April, Conservation Biology published a comment authored by Christopher A. Lepczyk, Nico Dauphiné, David M. Bird, Sheila Conant, Robert J. Cooper, David C. Duffy, Pamela Jo Hatley, Peter P. Marra, Elizabeth Stone, and Stanley A. Temple. The authors “applaud the recent essay by Longcore et al. (2009) in raising the awareness about trap-neuter-return (TNR) to the conservation community,” [1] and puzzle at the lack of TNR opposition among the larger scientific community.

The reasons behind this lack of opposition are unclear, but it may be that conservation biologists and wildlife ecologists believe the issue of feral cats has already been studied enough and that the work speaks for itself, suggesting that no further research is needed. Or, they simply do not want to devote time and energy to the issue and are unaware of policy actions.

I’d like to offer an alternative explanation. Yes, the work speaks for itself, but there are plenty of observers—surely, there are conservation biologists and wildlife ecologists among them—who don’t particularly like what it’s saying.

For the next few posts, then, I’m going to present a sampling of the more serious flaws—including exaggerated and misleading claims, botched analyses, questionable research and review methods, and widespread bias—all too common in the feral cat/TNR literature. Let’s see what Lepczyk at al. are cheering about

References
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627-629.

A Critical Assessment of “Critical Assessment”—Part 4

The fourth in a series of posts that breaks down my critique of the essay “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” (Conservation Biology, Volume 23, No. 4, 887–894) by Travis Longcore, Catherine Rich, and Lauren M. Sullivan.

In the past few posts, I’ve addressed their claims regarding the numbers of birds killed by cats, and alleged wildlife impacts. Now I’d like to focus on some of their claims regarding TNR. While I agree with the authors that there is a need for additional research into the effectiveness and impact (environmental and otherwise) of TNR, I’m not sure any subsequent findings would satisfy the standards—some of which border on the absurd—suggested by Longcore et al.

Adoptions
To begin with, the authors challenge the efficacy of TNR, noting—correctly—for example, that where TNR has proven effective at reducing the size of colonies, success has been “derive[d] in part from intensive efforts to remove cats for adoption as part of the TNR program.” [1] Shouldn’t this appeal to Longcore and the Urban Wildlands Group? Adoptions lead to fewer free-roaming cats, right?

It’s unclear how a successful adoption program lessens the efficacy of TNR; indeed, such efforts are integral to any TNR program. For Longcore et al., however, it’s as if adoptions constitute cheating.

Researchers vs. Volunteers
Another of their assertions, that “programs implemented by researchers are likely to be much more thorough than programs implemented exclusively by volunteers,” [1] could be applied to virtually any conservation effort. Of course the results will be better when the experts are involved directly!

Indeed, while compiling data for the Atlas of Breeding Birds of Maryland and the District of Columbia, researchers found Cooper’s Hawk (Accipiter cooperii) in 46% of the areas surveyed, while volunteers reported only a 14% occurrence of this “secretive species that requires special effort.” [2] Here, the experts “performed” more than three times better than well-meaning volunteers with less experience and/or training. Should we discontinue all efforts that include volunteers, then? Or shut down these programs until the volunteers perform as well as experts? Obviously not.

Anecdotes of Success
Longcore et al. criticize supporters of TNR for their “anecdotes of success” and “assertions of colony declines often… supported only by reference to Web sites.” [1] By calling the data “anecdotal,” the authors dismiss it out of hand. So, what measures of success would be acceptable?

In general, caretakers of feral colonies—as providers of food, water, shelter, and, often, healthcare—know their cats quite well. Yet, Longcore et al. suggest that their reports are not to be trusted—trusted to a lesser degree, in fact, than the reports generated by members of the public recruited to watch and listen for birds. Breeding Bird Surveys “annually engage tens of thousands of participants,” and these efforts are now beginning to leverage the power of the Internet via Web-based programs such as eBird. [3] All of which sounds very anecdotal. So, do the authors question the validity of this work as well?

Prevailing Conditions
Citing a 2006 study from Rome, [4] Longcore et al. chose to focus not on TNR’s rather remarkable success, but on its greatest challenge: “Ten years of TNR in Rome showed a 16–32% decrease in population size across 103 colonies but concluded that TNR was ‘a waste of time, energy, and money’ if abandonment of owned cats could not be stopped.” [1] It must be recognized that TNR is part of a larger mission that includes adoptions (as mentioned above), sterilization of owned cats, and the burgeoning no-kill movement (which may reduce the number of abandoned cats).

In any case, what rescue/conservation work isn’t “a waste of time, energy, and money” when considered in the harsh light of what the authors call “prevailing conditions”? We could, for example, say the same about efforts to save songbirds faced with the elimination and fragmentation of habitat, increased levels of pollution, and the like (indeed, endangered and threatened species are, by definition, the victims of prevailing conditions). Or, to take a very timely example, the work being done to save the wildlife affected by millions of gallons of oil spilling into the Gulf of Mexico even as I write this.

The fact that such efforts are uphill battles may say something about their underlying moral imperative—but very little about their efficacy.

*     *     *

Common Ground
Essentially, the argument put forth by Longcore et al. in this part of their essay boils down to these three points:

  • TNR can and does work, though not always as well as one would like.
  • Adoptions are critical, as is training and rigorous tracking.
  • Abandonment of pet cats—which is, in any case, illegal—should be stopped.

So, how is this any different than what TNR advocates are promoting? Here at least, we would seem to have some common ground. Apparently, what’s really at issue is not how success is defined, but by whom:

For many TNR advocates, success is not defined by elimination of feral cats in an area, but rather by the welfare of the cats… conservation scientists and wildlife veterinarians measure success of a feral cat management program by the decline and elimination of free-roaming cats. [1]

All of which leaves me wondering: How much time have the authors spent with people who practice TNR? Of course practitioners are interested in the welfare of the cats—just as any animal lover is interested in the welfare of the animals they enjoy. But they’re also thrilled when “kitten season” comes and goes without any new arrivals in their colonies.

More common ground? It would seem so—but if that’s the case, one is left to wonder why the Urban Wildlands Group sued the City of Los Angeles to put an end to publicly supported TNR. (Or at least I am left to wonder, as Longcore has not responded to my inquiries.) One thing that does seem certain: more cats are reproducing as a result of the injunction. And no doubt more are dying, too. Hard to imagine the wildlife and environment being any better off, either. There are lots of losers here—where are the winners?

References
1. Longcore, T., Rich, C., and Sullivan, L.M., “Critical Assessment of Claims Regarding Management of Feral Cats by Trap–Neuter–Return.” Conservation Biology. 2009. 23(4): p. 887–894.

2. Robbins, C.S. and Blom, E.A.T., Atlas of the breeding birds of Maryland and the District of Columbia. Pitt series in nature and natural history. 1996.

3. Sullivan, B.L., et al., “eBird: A citizen-based bird observation network in the biological sciences.” Biological Conservation. 2009. 142(10): p. 2282-2292.

4. Natoli, E., et al., “Management of feral domestic cats in the urban environment of Rome (Italy).” Preventive Veterinary Medicine. 2006. 77(3-4): p. 180-185.

A Critical Assessment of “Critical Assessment”—Part 3

The third in a series of posts that breaks down my critique of the essay “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” (Conservation Biology, Volume 23, No. 4, 887–894) by Travis Longcore, Catherine Rich, and Lauren M. Sullivan.

As I’ve suggested previously, much of the “evidence” that Longcore et al. cite regarding cat predation is rather weak. The links between predation and declining wildlife populations (especially birds) are, not surprisingly, no better. According to Longcore et al., “Comparative field studies and population measurements illustrate the adverse effects of feral and free roaming cats on birds and other wildlife.” Let’s take a closer look at some of these studies…

In canyons in San Diego native bird diversity declined significantly with density of domestic cats (Crooks & Soulé 1999). —Longcore et al.

  • Longcore fail to mention the density of people here—the study site was a “moderately sized fragment (~20 ha) [approximately 49 acres] bordered by 100 residences.” [1]
  • It’s also not clear how sites such as this one, which the authors describe as, “undeveloped steep-sided canyons… habitat islands in an urban sea,” correspond to the environment overall. Don’t forget: when Longcore and the Urban Wildlands Group sued the City of Los Angeles last year, it was to put a stop to publicly supported TNR throughout the city.

In a comparative study in Alameda County, California, a site with a colony of feral cats had significantly fewer resident birds, fewer migrant birds, and fewer breeding birds than a control site without cats (Hawkins 1998). Ground-foraging species, notably California Quail (Calipepla californica) and California Thrashers (Toxostoma redivivum), were present at the control site but never observed at the site with cats. Native rodent density was drastically reduced at the site with cats, whereas exotic house mice (Mus musculus) were more common (Hawkins 1998). —Longcore et al.

Hawkins’ dissertation [2] is so problematic—and cited frequently enough as “evidence” of the impact of cats on wildlife—that it warrants a post of its own. Here, I’ll touch on just a few issues.

  • Hawkins describes the “cat” and “no-cat” sites as being similar enough that a valid A-B comparison is appropriate. But a closer look at the study suggests otherwise. Much of the cat site bordered the park’s lake and marina, not far from a number of picnic sites. Hawkins notes that there were more people in the cat area, but doesn’t even admit to the possibility that their presence may have influenced the numbers of birds and rodents he observed there.
  • In addition, the presence of pesticides may have played a role. According to a 2002 report (the earliest I was able to find) from the East Bay Regional Park District, “The focus of Lake Chabot’s weed control efforts are vegetation reduction within the two-acre overflow parking lot, picnic sites and firebreaks around park buildings, corp. yard, service yard, and the Lake Chabot classroom.” [3] Now, Hawkins’ fieldwork was done in 1995 and 1996, but if there was any pesticide use going on during the study period, it may have affected the results—especially if the pesticide was distributed differently across the two sites.
  • Hawkins writes, “The preference of ground feeding birds for the no-cat treatment was striking; for example, California quail were seen almost daily in the no-cat area, whereas they were never seen in the cat area.” What’s more striking to me, though, is the fact that five of the nine ground-feeding species included in the study showed no preference for the cat or no-cat area—a point Hawkins downplays, and Longcore et al. ignore entirely.
  • Finally, it’s not clear how this study constitutes an experiment at all. Hawkins chose two sites, one where cats were being fed, and another (approximately two miles away) where cats were not being fed. We have no idea what the cat area was actually like prior to the cats being fed there—Hawkins merely assumes the populations of birds and rodents would have been identical to those found at the no-cat site. We also have no idea what effect the feeding had—what if the cats were present but had to fend for themselves? And we don’t know if the cats were sterilized, or what impact that might have had on the study. In other words, Hawkins doesn’t actually know enough about what’s going on at the two sites to conclude, as he does, that “it is not prudent to manage for wildlife and allow cat feeding in the same parks.”

In Bristol, United Kingdom Baker et al. (2005) calculated that the predation rates by cats on 3 bird species in an urban area is high relative to annual productivity, which led the authors to suggest that the area under study may be a habitat sink. —Longcore et al.

  • Also, Longcore et al. fail to mention that Baker et al. concede an important point: “collectively, despite [cats] occurring at very high densities, the summed effects on prey populations appeared unlikely to affect population size for the majority of prey species.”
  • In addition, a subsequent study (also conducted in Bristol) involving two of the authors, suggests that much of the predation observed was compensatory rather than additive. That is, many of these birds would have, for one reason or another, died anyhow, whether the cats were present or not. Specifically, the authors found that “birds killed by cats in this study had significantly lower fat and pectoral muscle mass scores than those killed by collisions.” [6] Baker at al. are cautious about these findings, suggesting, “the distinction between compensatory and additive mortality does… become increasingly redundant as the number of birds killed in a given area increases: where large numbers of prey are killed, predators would probably be killing a combination of individuals with poor and good long-term survival chances.” But once again, their estimates of birds killed by cats are inflated by a factor of 3.3, as described above—thereby raising doubts about any level of “redundancy.”
  • Another study to investigate compensatory vs. additive predation was more conclusive. Møller and Erritzøe compared the average spleen mass of birds killed by cats to that of birds killed in collisions with windows found that, “small passerine birds falling prey to cats had spleens that were significantly smaller than those of conspecifics that died for other reasons,” concluding that the birds killed by cats “often have a poor health status.” [7] In other words, the birds killed by cats were among the population least likely to survive anyhow.

Clearly, this is a complex—not to mention contentious—issue. But Longcore et al. make it out to be remarkably straightforward. The “adverse effects of feral and free roaming cats on birds and other wildlife,” they seem to suggest, are widely accepted common knowledge.

*     *     *

Then, too, there are those—and there are many—who have disputed the broad-brush claims about the impact of cat predation on wildlife. Consider, for example, the following studies:

  • Biologist C.J. Mead, reviewing the deaths of “ringed” (banded) birds reported by the public, suggests that cats may be responsible for 6.2–31.3% of bird deaths. “Overall,” writes Mead, “it is clear that cat predation is a significant cause of death for most of the species examined.” But the relationship between bird deaths and population declines is complex. In fact, Mead concludes that “there is no clear evidence of cats threatening to harm the overall population level of any particular species… Indeed, cats have been kept as pets for many years and hundreds of generations of birds breeding in suburban and rural areas have had to contend with their predatory intentions.” [8]
  • Mike Fitzgerald and Dennis Turner come to essentially the same conclusion. (Their contribution to The Domestic Cat: The Biology of its Behaviour is a must-read for anybody interested in the subject.) “We consider that we do not have enough information yet to attempt to estimate on average how many birds a cat kills each year,” write Fitzgerald and Turner. “And there are few, if any studies apart from island ones that actually demonstrate that cats have reduced bird populations.” [9]
  • Martin, Twigg, and Robinson conclude more broadly, “it is not possible to make any inferences concerning the real impact of feral cats on prey populations from dietary studies.” [10]

Given the scope of their essay, perhaps it’s understandable that Longcore et al. were unable to cover each aspect of this rather broad topic in a comprehensive manner. Nevertheless, the amount of research into cat predation and declining bird populations—a critical piece of the puzzle, to be sure—that was omitted, glossed over, and/or misrepresented suggests a clear agenda. Read carefully, their essay comes across as not as scientific discourse, but as fodder for a marketing campaign. (And, given the number of wildlife conservation/bird advocacy groups that have posted it on their websites—not to mention the L.A. Superior court decision—it’s been effective.)

*     *     *

Many proponents of TNR will acknowledge that the practice is not appropriate for all environments. Crooks and Soulé’s work in San Diego’s canyon country (cited previously), writes Ellen Perry Berkeley, “suggests to even the most ardent TNR advocate that such a landscape might not be the best place for TNR… The world is a complicated place.” [11] Gary J. Patronek, the former Director of the Center for Animals and Public Policy at the Cummings School of Veterinary Medicine at Tufts University, and one of the founders of the Hoarding of Animals Research Consortium, goes further: “the release of cats into an environment where they would impact endangered or threatened species, or even into wildlife preserves or refuges, is inexcusable.” [12]

This, I worry, is a slippery slope. Given the current nature of the cat debate, how long would it be before every alley, Dumpster, and abandoned property is deemed a wildlife preserve? And, given the number of endangered and threatened species—and their wide range—would there be any environment left for cats? Nevertheless, Patronek’s larger point is an important one:

I do not believe that this is being advocated by cat protectors who see urban, managed colonies as an imperfect but still preferable alternative to the euthanasia of healthy animals. Abandoned pet cats whose own habitat has been reduced to colonies, and the wild species endangered by clear-cutting or beachfront development, are casualties of the same callous disregard for the lives of animals. I see little justification for shifting the role of cats to that of scapegoat.

For Longcore and the Urban Wildlands Group (and others, too, of course), though, there’s simply no place for TNR anywhere. But there’s something even more troubling with their argument: they’re asking the wrong questions. As Patronek puts it so eloquently:

If the real objection to managed colonies is that it is unethical to put cats in a situation where they could potentially kill any wild creature, then the ethical issue should be debated on its own merits without burdening the discussion with highly speculative numerical estimates for either wildlife mortality or cat predation. Whittling down guesses or extrapolations from limited observations by a factor of 10 or even 100 does not make these estimates any more credible, and the fact that they are the best available data is not sufficient to justify their use when the consequence may be extermination for cats… What I find inconsistent in an otherwise scientific debate about biodiversity is how indictment of cats has been pursued almost in spite of the evidence, and without regard to the differential effects of cats in carefully selected, managed colonies, versus that of free-roaming pets, owned farm cats, or truly feral animals. Assessment of well-being for any is an imprecise and contentious process at best. Additional research is clearly needed concerning the welfare of these cats.

In a future post, I’ll get into the ways Longcore et al. would have us measure the success of TNR.

References
1. Crooks, K.R. and Soule, M.E., “Mesopredator release and avifaunal extinctions in a fragmented system.” Nature. 1999. 400(6744): p. 563.

2. Hawkins, C.C., Impact of a subsidized exotic predator on native biota: Effect of house cats (Felis catus) on California birds and rodents. 1998, Texas A&M University.

3. Brownfield, N.T., 2002 Annual Analysis of Pesticide Use East Bay Regional Park District. 2003, East Bay Regional Park District.

4. Baker, P.J., et al., “Impact of predation by domestic cats Felis catus in an urban area.” Mammal Review. 2005. 35(3/4): p. 302-312.

5. Kays, R.W. and DeWan, A.A., “Ecological impact of inside/outside house cats around a suburban nature preserve.” Animal Conservation. 2004. 7(3): p. 273-283.

6. Baker, P.J., et al., “Cats about town: is predation by free-ranging pet cats Felis catus likely to affect urban bird populations? Ibis. 2008. 150: p. 86-99.

7. Møller, A.P. and Erritzøe, J., “Predation against birds with low immunocompetence.” Oecologia. 2000. 122(4): p. 500-504.

8. Mead, C.J., “Ringed birds killed by cats.” Mammal Review. 1982. 12(4): p. 183-186.

9. Fitzgerald, B.M. and Turner, D.C., Hunting Behaviour of domestic cats and their impact on prey populations, in The Domestic Cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 2000, Cambridge University Press. p. 151–175.

10. Martin, G.R., Twigg, L.E., and Robinson, D.J., “Comparison of the Diet of Feral Cats From Rural and Pastoral Western Australia.” Wildlife Research. 1996. 23(4): p. 475-484.

11. Berkeley, E.P., TNR Past present and future: A history of the trap-neuter-return movement. 2004, Bethesda, MD: Alley Cat Allies.

12. Patronek, G.J., “Letter to Editor.” Journal of the American Veterinary Medical Association. 1996. 209(10): p. 1686–1687.

Nibbling at the Margins—Part 2

In December 2009, my critique of “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” (Conservation Biology, Volume 23, No. 4, 887–894) was rejected by outgoing editor Gary Meffe. Frustrated that Meffe was willing to publish something he considered “nibbling at the margins” topic-wise, but then reject a thoughtful critique of it, I appealed—noting, among other things:

  1. Longcore et al. were very “careful” about the studies they selected, and even the particular claims within the studies cited (this despite the fact that they criticize TNR advocates for their “reference to selected peer reviewed studies”). The authors make no attempt to explain their rationale for this obvious cherry picking.
  2. Although I was, as Meffe suggests, “critiquing the overall literature in the area and pointing out its complexities, problems, and uncertainties,” it was only to put the original essay into context. Meffe’s comment ignores the larger issue: Longcore et al. were essentially breathing new life into flawed studies by citing them uncritically. And here, Conservation Biology is also implicated (which might help explain Meffe’s decision to reject my commentary), a point I made to Meffe:

Conservation Biology is, according to the journal’s website, “the most influential and frequently cited journal in its field.” I’m afraid that by publishing the essay submitted by Longcore et al., Conservation Biology has effectively given its “stamp of approval,” thereby burying more deeply the complexities of the subject and its body of literature. No wonder bird advocacy groups have embraced the paper, including PDFs on their websites—here, it would seem, is additional “proof” of the damage cats are doing to bird populations!

In the end, Meffe didn’t budge. And neither did current editor Erica Fleishman, who seemed to have little patience for the subject. What Meffe found to be too broad, Fleishman read as a “fairly personal critique,” adding, “…we aim for objective presentation of facts that may provide evidence contrary to a previous publication rather than (what comes across as) a more pointed rejoinder to authors and the journal.”

At this point, it seemed clear that I was getting nowhere. Nevertheless, I appealed, explaining what I intended to include in my paper:

… regarding “a more comprehensive piece,” what I’m proposing is a detailed review of the literature regarding cat predation on birds, the scope of which includes—but also goes well beyond—the material covered in the essay by Longcore et al.

Once again, my appeal fell on deaf ears, eliciting this response—obviously intended to put an end to the discussion—from Fleishman:

Thanks for the detailed explanation. I think it would be best to pursue publication of your review in a different journal. Good luck and again thank you for considering Conservation Biology.

Perhaps I will follow her advice and submit a similar proposal to another journal. For now, though, it’s all going right here. Indeed, many of the next several posts will draw on the main points I made in my first letter to Conservation Biology.

Nibbling at the Margins—Part 1

Since I first became involved with the Great Kitty Rescue, I’d begun slowly compiling journal articles and news stories related to feral cat management, and in particular, TNR. As a newcomer to the world of cat rescue, I was struggling to sift through the many claims made—on both sides of this highly controversial issue—regarding its efficacy and potential impact.

When I came across the essay “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” (Conservation Biology, Volume 23, No. 4, 887–894). I thought I’d struck gold. Here, I naively assumed, was what I’d been looking for, all neatly complied in a single document (complete with an extensive list of references, allowing me to chase down all of the original research as well). As it turned out, the discovery of this essay proved to be a turning point—but not in the way that I expected. Instead of answering my questions, this paper (the details of which will be the focus of many future posts) raised many more. This “critical assessment,” authored by Travis Longcore, Catherine Rich, and Lauren M. Sullivan—with its glaring omissions, numerous misrepresentations, and obvious bias—revealed for me the ugly side of the feral cat/TNR debate.

So I did what any writer in my position would do: I wrote a letter to the editor.

I was then invited by outgoing editor Gary Meffe (who had been at the helm when the original essay was published) to submit a letter for possible publication in the journal. The letter, suggested Meffe, was “to be substantive and shed more light than heat. In other words, if it is simply a difference of opinion it will not be suitable. I always look for letters to be substantive critiques of a paper.”

Which, I maintain, is precisely what I delivered. Meffe, however, disagreed, and—to his credit—explained in detail his reasoning:

I am not saying it is unimportant to conservation, but it is a fairly narrow and specialized topic. Publication of the Longcore et al. paper was nibbling at the margins to begin with, but I and the reviewers felt that it had enough relevance and interest for us to publish it. I am reluctant to further engage the topic in the journal in great detail, so any responses to it need to be very focused and address specific errors in the paper. Your critique gets into assessment of the broader literature on the subject and its use by Longcore et al. I don’t think this is the format to do that. You are really critiquing the overall literature in the area and pointing out its complexities, problems, and uncertainties; one could do that for almost any topic in conservation and probably for many papers that are published. If this cat TNR literature really is problematic then it calls for a much more comprehensive critical assessment in a thorough review paper. Thus, if you would like to prepare a comprehensive review paper on cat TNR that thoroughly examines the literature and its complexities and problems, then perhaps that could be of interest to this journal.

Not the response I was hoping for, obviously—but I’d already invested too much to give up so easily. Perhaps my next letter would be more successful…

Barrier-free Blog?

As I’ve suggested elsewhere, I don’t claim to have all the answers to the numerous complex questions raised in the feral cat/TNR debate. But I’m very interested in asking better questions—the sort of questions that might stimulate a more conscientious debate of this important issue. Vox Felina, I hope, will help me do that—and, who knows, perhaps arrive at some answers too.

So, now that I’m getting started, I keep coming back to the words of Gary J. Patronek, the former Director of the Center for Animals and Public Policy at the Cummings School of Veterinary Medicine at Tufts University, and one of the founders of the Hoarding of Animals Research Consortium. My copy of Patronek’s 1998 article, “Free-roaming and feral cats—their impact on wildlife and human beings,” published in the Journal of the American Veterinary Medicine Association (JAVMA), is becoming rather shabby, as I continue making notes in the margins and covering it with a rainbow assortment of highlighter.

Patronek begins his final section, “Conclusions and Possible Solutions,” with this:

It is unfortunate that the debate about free-roaming cats is often framed as pro-cat and anti-wildlife, or vice-versa. This attitude polarizes groups and individuals who otherwise have common concerns about animals and the environment, and is a barrier to developing effective public policy.

Let me be clear: though I am certainly in the “pro-cat” camp, I am not at all “anti-wildlife.” I’m far more interested in finding common ground than I am in further polarizing the parties involved. That said, I will not stand idly by while opponents of feral/free-roaming cats—and TNR in particular—mishandle, misconstrue, and misrepresent the research for PR purposes.

The “effective public policy” Patronek refers to is needed more urgently than ever. But to get there—to really tackle this incredibly complex issue—we first need to untangle some of what’s being said. This is precisely what I intend to do with Vox Felina. As Supreme Court Justice Louis Brandeis put it so eloquently, “Sunlight is said to be the best of disinfectants; electric light the most efficient policeman.”