The Annotated Apocalypse Meow

In the current issue of The Washingtonian, senior writer Luke Mullins provides the most comprehensive profile yet of former Smithsonian researcher Nico Dauphiné, convicted last October of attempted animal cruelty. Most telling are his conversations with her unwavering supporters, who—in spite of the evidence, her well-documented history, and her miserable performance on the stand—continue to make excuses for her.

In the five months since she was convicted of attempted animal cruelty, former Smithsonian researcher Nico Dauphiné has enjoyed a respite from the largely unflattering media spotlight. All that changed in the past few weeks, though—first with Conservation magazine’s “Cat Fight,” and now with a 6,100-word feature in the April issue of The Washingtonian.

In “Apocalypse Now,” senior writer Luke Mullins digs into Dauphiné’s DC court case, as well as her previous “community service” in Athens, GA. The Nico Dauphiné that emerges is a far cry from the sympathetic character portrayed in “Cat Fight”—where, for example, writer John Carey laments: “Unfortunately, the strange case of the accused cat poisoner didn’t end well.” [1]

Although Mullins was unable to speak with Dauphiné for the piece, his conversations with people close to Dauphiné—as well as many who observed her mistreatment of cats—are illuminating. Read more

Fight or Flight?

“Cat Fight,” which appears in the latest issue of Conservation magazine, does little to cut through the rhetoric or clear up the numerous misrepresentations that plague the debate over free-roaming cats.


There is, it’s often said, no such thing as bad PR. Even so, I’m not thrilled with the way I’m portrayed in an article appearing in the current issue of Conservation. It’s only a couple of quotes, but still, I worry that I come off as more of a bomb-thrower than anything else.

“Wolf writes a blog, Vox Felina,” explains writer John Carey, in “Cat Fight,” “which regularly excoriates wildlife biologists for what Wolf calls their ‘sloppy pseudo-science.’ He charges that ‘the science in Dauphine’s paper about cats was so horrific that she should have never made it out of graduate school’ and that ‘Peter Marra is taking six bird deaths and predicting the Apocalypse.’”

As I told Carey via e-mail, just after the piece was published online, I don’t believe the quotes are accurate. Carey, on the other hand, assures me (in a cordial, professional manner typical of our exchanges) that “the quotes are exactly what [I] said.” (Neither of us recorded our conversation.)

“I know I realized immediately when you said those things that they were precisely the type of colorful statements that illustrate the nature of the debate, so I did appreciate you using such colorful language.”

Fair enough. Perhaps it’s not all the important if the content isn’t precisely correct—the tone is certainly accurate.

If I am a bomb-thrower, though, I am at least a well-informed bomb-thrower. And the “targets”—to extend the metaphor—have, simply put, got it coming to them. Carey acknowledges that I “do an excellent job scrutinizing the scientific evidence, and have clearly thought deeply about both sides of the issue.” Unfortunately, that doesn’t come across to Conservation readers.

That said, I want to make it clear: I’m grateful to have been included in the piece, and grateful, too, for my conversations with Carey. And whatever quibbles I have about my portrayal pale in comparison to various other aspects of “Cat Fight.”

Stuffing the Ballot Box
Referring to Peter Marra’s well-publicized catbird study, Carey writes: “Predators nabbed nearly half the birds, and cats were the number one predator.” [1]

Number one predator?

Certainly, this was the message Marra emphasized to the press—but I thought I’d straightened this out with Carey on the phone, and with a follow-up e-mail.

Here’s what Marra and his colleagues report in their paper:

A total of 69 fledglings were monitored, of which 42 (61 percent) died over the course of the study. Of those mortalities, 33 (79 percent) were due to predation of some kind. Eight of the 33 predatory events were observed directly: six involved domestic cats, one a black rat snake, and one a red-shouldered hawk.

That leaves 25 predation events (76 percent) for which direct attributions could not be made—which, in and of itself, raises serious questions about Carey’s “number one predator” claim.

About those other 25: Marra and his co-authors concede that “not all mortalities could be clearly assigned.” Seven were attributed to rats or chipmunks because they were “found cached underground,” while another one was attributed to birds because the remains were found in a tree.

In addition, 14 mortalities “could not be assigned to a specific predator.” Which leaves three: “fledglings found with body damage or missing heads were considered symptomatic of cat kills.” [2]

In fact, it’s rather well known that such predatory behavior is symptomatic not of cats, but of owls, grackles, jays, magpies, and even raccoons [3–5]—something I addressed in an October 2010 post (and discussed with Carey).

All of which is difficult to reconcile with Marra’s claim, in “Cat Fight,” that he and his colleagues “were very conservative assigning mortality to cats,” [1] and with his apparent confidence (shared by Carey) in putting cats at the top of the list.

Curious, too, that, although Carey opens his article with Nico Dauphine’s December 2011 sentencing hearing, he never mentions the fact that Marra was Dauphine’s advisor at the Smithsonian Migratory Bird Center. (I suppose the connection isn’t something Marra brags about these days.)

The Cats Came Back
Carey argues that “moving cat colonies away from areas that harbor threatened species is a no-brainer” but points out that “it doesn’t always work.”

“In Fortescue, New Jersey, a colony of feral cats was moved away from the shore of Delaware Bay in 2011 to help protect red knots, which stop there in huge numbers to gorge on horseshoe-crab eggs to fuel their long migration from the tip of South America to the Arctic. But after only a few months, cats were back.” [1]

Here, I’ll defer to Animal Protection League of New Jersey attorney Michelle Lerner, whose comment was the first posted after “Cat Fight” was available online:

“The details about the Fortescue cats, with which I was involved, are incorrect. The colony was not ‘moved,’ it was removed completely. 40 cats were moved to a fence enclosure on a farm several counties away, 7 went to a sanctuary in another state, others went to barns or were friendly enough to be adopted. Removal was used, which is what the anti-TNR people always want. The only difference is the cats were not killed—something that was possible because of limited numbers. It is true that, due to the vacuum effect, different cats then showed up. The nonprofit doing the removal keeps trapping there in coordination with animal control to try to get them all. A few per month show up. But this is why TNR advocates warn removal never really works without intensive management and repeat trapping, and why statistical studies have shown it takes 10 times the effort to control a colony through removal as through TNR. Because there is a reason the cats were there in the first place and more will just move in—more who are unneutered—if the cats are removed.”

It’s worth pointing out, too, that, unlike the current relocation effort, taxpayers would be footing the bill for an ongoing lethal roundup.

And I wish Carey had included a bit of additional context here. The greatest threat to those red knots, from what I can tell (admittedly, doing nothing more than a quick Google search), has little to do with cats being fed nearby. According to The Wetlands Institute:

“…overharvesting of female horseshoe crabs by commercial fishermen, coupled with loss of spawning habitat resulting from beach erosion associated with sea level rise, has resulted in a precipitous decline in the Delaware Bay horseshoe crab population, and therefore the number of eggs available to feed migratory birds. This, in turn, has led to a dramatic decrease in the size of annual red knot migrating populations, to the point that red knots have been proposed for federally endangered status.”

Indeed, the Delaware Nature Society reports: “In 2008, New Jersey placed a moratorium on horseshoe crab harvests until the red knot numbers rebound.”

The Scientific Community v. The People of the District of Columbia
If Marra hasn’t come to Dauphine’s defense, Chris Lepczyk has—with the kind of confidence he (and Marra) usually reserve for vilifying free-roaming cats.

“‘I am 100 percent confident she was not poisoning cats,’ says University of Hawaii wildlife ecologist Christopher Lepczyk, who fears that she was convicted in part because of her articles about the cat-predation problem. ‘I don’t think anyone in the scientific community agrees that she is guilty.’” [1]

That’s quite an endorsement—especially in light of… you know, the facts.

On December 14th, the day Dauphine was sentenced, CNN reported that Superior Court Judge A. Truman Morrison III “said he had received a number of letters from people who know Dauphine.”

“He said such letters usually try to make a case that the verdict was in error, but in this case, the judge said, no one quarreled with the guilty verdict… Morrison said it was clear from letters written by Dauphine’s colleagues that ‘her career, if not over, it’s in grave jeopardy.’ The judge said that was already partial punishment for her actions.”

But Lepczyk’s right when he says the verdict was, in part, the result of Dauphine’s writings—just not in the way he suggests. Indeed, the day Dauphine was found guilty, The Washington Post reported: “Senior Judge Truman A. Morrison III said it was the video, along with Dauphine’s testimony, that led him to believe she had ‘motive and opportunity.’”

“He specifically pointed to her repeated denials of her writings. ‘Her inability and unwillingness to own up to her own professional writings as her own undermined her credibility,’ Morrison said.”

All of which—not to put too fine a point on it—was included in my numerous posts following the case. Perhaps Lepczyk ought to subscribe to Vox Felina.

I’ve been saying for nearly two years now that Dauphine’s professional work on the subject of free-roaming cats—cited and promoted with great enthusiasm before all this nasty press attention—is as indefensible as the actions that landed her in DC Superior Court. It’s a shame Carey didn’t pin down Lepczyk (and others) on that point.

Numb and Numb-er
If Carey included me in “Cat Fight” because of my colorful language, I have to imagine Stephen Vantassel, project coordinator of distance education for the University of Nebraska-Lincoln’s School of Natural Resources, was included for his unintended irony.

Referring to the toll cats take on wildlife, Vantassel told Carey, “The numbers are mind-numbing.” [1]

Actually, “mind-numbing” is a fitting description for the content of, and motivation behind, Feral Cats and Their Management, the well-publicized paper Vantassel co-authored in late 2010. Not only do the authors fail to get a handle on the predation numbers, they reveal a significant lack of understanding of the key issues surrounding cats and predation in general. Indeed, they misread, misinterpret, and/or misrepresent nearly every bit of research they reference. And, some of what the authors include isn’t valid research to begin with.

Two years later, it seems he’s still got nothing to contribute to the discussion.

OK, maybe that’s being too harsh. Consider what Vantassel has to say, in the sidebar that accompanies “Cat Fight,” about the uncertainty surrounding the legal status of free-roaming cats: it “has essentially turned outdoor cats into protected predators.” [6]

Protected predators?

Now, here’s a subject Vantassel knows well. After all, his PhD (theology) dissertation was dedicated to: “…fur trappers who, every winter, brave the harsh weather in continuance of America’s oldest industry. Regrettably, they must also endure the ravages of urban sprawl and the derision of an ungrateful and ignorant public.” [7]

Wisconsin: Landmarks and Mirages
My greatest disappointment with “Cat Fight”—one shared by others I’ve spoken with—is Carey’s inclusion of the infamous “Wisconsin Study.”

“In a landmark study in Wisconsin, Stanley Temple, now professor emeritus of forest and wildlife ecology at the University of Wisconsin, and his colleagues radio-collared free-ranging rural cats, watched the animals’ hunting behavior, and examined their stomach contents. (An inflammatory and inaccurate press report that implied that the researchers had killed the cats for the stomach contents—in fact, they used an emetic—led to death threats against Temple.) The study showed that each cat killed an average of 5.6 birds a year. With an estimated 1.4 million free-ranging rural cats just in Wisconsin, that’s nearly 8 million birds.” [1]

When I spoke with Carey, he’d already talked to Temple. And when he referred to a predation study Temple had done, I stopped him in his tracks: If Temple conducted any such work, it was never published.

What has been published involved combining cat density numbers Temple and graduate student John Coleman had gathered by surveying “farmers and other rural residents in Wisconsin for information about their free-ranging (not house-bound) cats” [8] with predation numbers from studies conducted in the 1930s and 1950s. All of which is explained in a 1992 article the two wrote for Wildlife Control Technology:

“…our four year study of cat predation in Wisconsin, completed in1992, coupled with data from other studies, allows us to make a reasonable estimate of birds killed annually in this state… At the high end, are estimates from diet studies of rural cats that indicate at least one kill per cat per day, resulting in over 365 kills per cat per year [9–11]. Other studies report 28 kills per cat per year for urban cats, and 91 kills per cat per year for rural cats [12].” [13]

“Using low values,” then, Temple and Coleman multiplied their estimated 1.4 million rural free-roaming cats in the state by 28 (“twice urban kill rate”), and then multiply that by 20 percent (the “low dietary percent,” as they call it, though it’s actually a gross misinterpretation of Mike Fitzgerald’s work, as Ellen Perry Berkeley points out in her 2004 book TNR Past Present and Future: A history of the trap-neuter-return movement [14]). The resulting “estimate” is “7.8 million birds killed annually.”

Twenty years later, though, the story seems to have changed dramatically.

Now, we’re to believe that Temple and Coleman’s study (funded, by the way, with “about $100,000 … from the [University of Wisconsin], U.S. Agriculture Department and the state Department of Natural Resources” [15]) revealed an average predation rate of 5.6 birds/year/cat. And that the 7.8 million figure comes not from “coupling” Temple and Coleman’s density work with others’ predation studies, but from their work alone.

Or perhaps the two methods resulted in exactly the same estimate.

Which, as I told Carey after reading the article, would be one hell of a coincidence. In fact, the very sources he cites call into question—if not discredit entirely—Temple’s claim.

Simply put: Carey failed to dig into this deeply enough. Instead of further perpetuating the myth of the Wisconsin Study, he might have exposed it for what it is: little more than a few misguided (and overpriced) back-of-the-envelope calculations—which Temple himself backed away from during a 1994 interview with The Sonoma County Independent: “They aren’t actual data; that was just our projection to show how bad it might be.” [16]

Or, failing that, then at least ignore the thing entirely.

Landmark study? Only insofar as it was instrumental in launching what’s become a witch-hunt against free-roaming cats in this country.

•     •     •

According to the magazine’s website, “Conservation stories capture the imagination and jump-start discussion.” Unfortunately, I don’t see “Cat Fight” adding much to the discussion—a missed opportunity in a debate where such opportunities are few and far between.

I agree with Carey that, as he notes in the article’s closing paragraph, “these great societal debates … are contested on a battleground of conflicting emotions, moral values, and ideologies. Facts alone rarely break up the fight.”

On the other hand, I don’t see how we’re going to break it up if we don’t first get the facts straight.

Literature Cited
1. Carey, J., “Cat Fight.” Conservation. 2012. March. http://www.conservationmagazine.org/2012/03/cat-fight/

2. Balogh, A., Ryder, T., and Marra, P., “Population demography of Gray Catbirds in the suburban matrix: sources, sinks and domestic cats.” Journal of Ornithology. 2011: p. 1-10. http://dx.doi.org/10.1007/s10336-011-0648-7

http://nationalzoo.si.edu/scbi/migratorybirds/science_article/pdfs/55.pdf

3. Thompson, B., The Backyard Bird Watcher’s Answer Guide. 2008: Bird Watcher’s Digest.

4. Bird, D.M., “Crouching Raptor, Hidden Danger.” The Backyard Birds Newsletter. 2010. No 5 (Fall/October).

5. Anderson, T.E., Identifying, evaluating and controlling wildlife damage, in Wildlife Management Techniques. 1969, Wildlife Society: Washington. p. 497–520.

6. Carey, J., “The Uncertain Legal Status of Cats.” Conservation. 2012. March. http://www.conservationmagazine.org/2012/03/legal-status-of-cats/

7. Vantassel, S.M., Dominion over Wildlife?: An Environmental Theology of Human-Wildlife Relations. 2009: Resource Publications.

8. Coleman, J.S. and Temple, S.A., “Rural Residents’ Free-Ranging Domestic Cats: A Survey.” Wildlife Society Bulletin. 1993. 21(4): p. 381–390. http://www.jstor.org/pss/3783408

9. Errington, P.L., “Notes on Food Habits of Southwestern Wisconsin House Cats.” Journal of Mammalogy. 1936. 17(1): p. 64–65. http://www.jstor.org/stable/1374554

10. Parmalee, P.W., “Food Habits of the Feral House Cat in East-Central Texas.” The Journal of Wildlife Management. 1953. 17(3): p. 375-376. http://www.jstor.org/stable/3797127

11. Eberhard, T., “Food Habits of Pennsylvania House Cats.” The Journal of Wildlife Management. 1954. 18(2): p. 284–286. http://www.jstor.org/stable/3797736

12. 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. www.vacadsci.org/vjsArchives/v43/43-1B/43-197.pdf

13. Coleman, J.S. and Temple, S.A., “How Many Birds Do Cats Kill?” Wildlife Control Technology. 1995. July–August. p. 44. http://www.wctech.com/WCT/index99.htm

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

15. Imrie, R. (1997). Professor Says Predatory Cats Are Taking Toll on Ecosystem. St. Paul Pioneer Press, p. 1B,

16. Elliott, J. (1994, March 3–16). The Accused. The Sonoma County Independent, pp. 1, 10,

Devolution In the Classroom: Three Editions of F. Gill’s “Ornithology”

For more than 20 years now, Gill’s classic text has been required reading for ornithology students. While the book’s attention to conservation issues has expanded over its three editions, its treatment of the impact of cats on bird populations reflects an unsettling shift away from science.

The hoards of students descending upon college campuses this fall will—despite the rise of the eco-friendly PDF and a great variety of online content—more often than not find their arms and backpacks stuffed with old-school printed-and-bound books. Among them will be Frank Gill’s Ornithology, a regular offering on campus bookstore shelves for 21 years now.

Gill’s Ornithology is, I’m told by one Vox Felina reader, “considered (at least in these parts) the text regarding ornithology.” From what I can tell, it’s popularity as required reading for third- and fourth-year undergraduates isn’t limited to any one region of the country. Indeed, according to Amazon.com, the book is “the classic text for the undergraduate ornithology course.” Its third edition, published in 2007, “maintains the scope and expertise that made the book so popular while incorporating a tremendous amount of new research.”

Unfortunately, none of this new research made it into the section—a single paragraph—meant to address the “threat” of cats. Indeed, students interested in this topic are better off with the first edition, published 17 years earlier.

First Edition
“The numbers of deaths attributable directly or indirectly to human actions each year during the 1970s are staggering,” writes Gill in the 1990 edition of Ornithology, “but are apparently minor in relation to the population level.” [1] Citing a 1979 U.S. Fish and Wildlife Service report by Richard C. Banks, Gill continues:

“Human activities are responsible for roughly 270 million bird deaths every year in the continental United States. This seemingly huge number is less than two percent of the 10 to 20 billion birds that inhabit the continental United States and appears to have no serious effect on the viability of any of the populations themselves, unlike human destruction of breeding habitat and interference with reproduction… Miscellaneous accidents such as impact with golf balls, electrocution by transmission lines, and cat predation, may amount to 3.5 million deaths a year.” [1]

Predation by cats (included under “All Other Indirect”), then, according to Banks, represents about 1.3 percent of overall human-caused mortality—a loss of, at most, 0.04 percent of the U.S. bird population annually. By contrast, hunting and “collision with man-made objects” combine to make up “about 90 percent of the avian mortality documented” in Banks’ report. [2]

Second Edition
Five years later, in the second edition, the story changes dramatically. Gill discards Banks’ reference to cats and uses his 270 million figure purely for dramatic effect—the set-up for a punch line in the form of Rich Stallcup’s back-of-the-envelope guesswork (which Stallcup himself considered “probably a low estimate” [3]). Gill even includes a bar chart to drive the point home. (Apparently, he didn’t find Banks’ pie chart compelling enough to include in the his first edition of Ornithology.)

“Human activities are directly responsible for roughly 270 million bird deaths every year in the continental United States, about 2 percent of the 10 to 20 billion birds that inhabit the continental United States (Banks 1979)… Dwarfing these losses are those attributable to predation by pets. Domesticated cats in North America may kill 4 million songbirds every day, or perhaps over a billion birds each year (Stallcup 1991). Millions of hungrier, feral (wild) cats add to this toll, which is not included in the estimate of 270 million bird deaths each year.” [4]

But Stallcup’s “estimate”—published in the Observer, a publication of the Point Reyes Bird Observatory (which Stallcup co-founded)—lacks even the slightest scientific justification. In fact, “A Reversible Catastrophe” is little more than Stallcup’s advice—at once both folksy and sinister—about defending one’s garden from neighborhood cats (“…try a B-B or pellet gun. There is no need to kill or shoot toward the head, but a good sting on the rump seems memorable for most felines, and they seldom return for a third experience.” [3]).

“Let’s do a quick calculation, starting with numbers of pet cats. Population estimates of domestic house cats in the contiguous United States vary somewhat, but most agree the figure is between 50 and 60 million. On 3 March 1990, the San Francisco Chronicle gave the number as 57.9 million, ‘up 19 percent since 1984.’ For this assessment, let’s use 55 million.

“Some of these (maybe 10 percent) never go outside, and maybe another 10 percent are too old or too slow to catch anything. That leaves 44 million domestic cats hunting in gardens, marshes, fields, thickets, empty lots, and forests.

“It is impossible to know how many of those actively hunting animals catch how many birds, but the numbers are high. To be very conservative, say that only one in ten of those cats kills only one bird a day. This would yield a daily toll of 4.4 million songbirds!! Shocking, but true—and probably a low estimate (e.g., many cats get multiple birds a day).” [3]

It’s hardly surprising that Stallcup’s “estimate” grossly exaggerates predation rates since his research never went any further than the Chronicle’s mention of the U.S. pet cat population. His assumptions about how many of these cats go outdoors and their success as hunters stand in stark contrast to the trend suggested by pet owner survey results and various predation studies (some of which suggest that just 36–56 per­cent of cats are hunters. [5, 6])

(It was, no doubt, the “shocking” aspect of Stallcup’s numbers that appealed to Nico Dauphine, who, in her “Apocalypse Meow” presentation, acknowledges that Stallcup “didn’t do a study” but nevertheless concludes, inexplicably, that his “is a conservative estimate.”)

Unnatural Selection
So, how did Stallcup’s indefensible “estimate” make it into the standard ornithology textbook? It was, Gill told me recently by e-mail, “one of the few refs [he] could find.”

Referring to what he calls “the great cat debates,” Gill writes: “I claim no great expertise or authority… now or in the ancient histories of early textbook editions.”

Fair enough. Writing, editing, and revising multiple editions of Ornithology was an enormous undertaking—one for which Gill deserves much credit. But there was, available at the time, work by scientists who, unlike Stallcup actually studied predation. Indeed, even before the first edition of Ornithology was published, a great deal of work had been done—and compiled in the first edition (published in 1988) of The Domestic Cat: The Biology of Its Behaviour. In it, Mike Fitzgerald, one of the world’s foremost experts on the subject, reviewed 61 predation studies, concluding:

“Predation on songbirds by domestic cats is noticed because it takes place during the day, whereas much predation on mammals takes place at night. People generally enjoy having songbirds in their gardens, and providing food in winter may increase the numbers of birds. When cats kill some of these birds, people assume that cats are reducing the bird populations. However, although this predation is so visible, and unpopular, remarkably little attempt has been made to assess its impact on populations of songbirds.” [7]

Two years later, Fitzgerald had a brief letter on the subject published in Environmental Conservation. His comments are as relevant today as they were some 21 years ago:

“Before embarking… on programmes to educate the public so that they will pressure elected officials to act on ‘cat delinquency,’ we must discover what effect domestic cats really have on the wildlife populations in various urban localities—not merely what effect we assume they have on the basis of prey brought home by cats in one English village. Although we know what prey cats bring home in a few urban localities, we do not know what effect this predation has on the prey populations, or how the wildlife populations might differ if cat populations were reduced. Until we have this information we cannot ensure sound educational programmes. We should perhaps also try to discover what values urban people place on their wildlife and their pets—it seems likely that many of the people who love their pets also treasure the wildlife.” [8]

Surely, Fitzgerald’s work would have been more appropriate for, and useful to, Ornithology’s audience. Instead, unsuspecting undergraduates were treated to biased editorializing dressed up as science.

Third Edition
Gill tells me I wasn’t the first to “react… to the Stallcup paper,” and that the push-back was sufficient to prompt its removal from the third edition. Gone, too, is Banks’ report. Instead, Gill employs the now-common kitchen-sink approach, rattling off a litany of sins—borrowed, it seems, from the American Bird Conservancy.

“Domestic house cats in North America, for example, may kill hundreds of millions of songbirds each year. Farmland and barnyard cats kill roughly 39 million birds (and lots of mice, too) each year. Millions of hungrier, feral (wild) cats add to this toll. There is a common-sense solution. Letting cats roam outside the house shortens their expected life span from 12.5 years to 2.5 years and increases their risk of rabies, distemper, toxoplasmosis, and parasites. Evidence is mounting that cats help to spread diseases such as Asian bird flu. The message is clear: Keep pet cats inside for their own well being and for the future of backyard birds (http://www.abcbirds.org/cats/).” [9]

That 39 million birds figure, of course, comes from the infamous “Wisconsin Study,” the authors of which claim: “The most reasonable estimates indicate that 39 million birds are killed in the state each year.” [10] (The “reason” is, in fact, notably absent from Coleman and Temple’s figure—which can be traced to “a single free-ranging Siamese cat” that frequented a rural residential property in New Kent County, Virginia. [11])

Its implied use as a nationwide estimate, Gill says, was “a lapse.” The more serious lapse by far, though—not in copyediting but in judgment—is Gill’s endorsement of ABC.

A Constructive Approach
While he readily admits that he’s “not tracked nor verified [ABC’s] stats (and have paid precious little attention to the issue for almost 10 years),” Gill’s support is unwavering.

“ABC has taken a lead role on the cat-bird issues, generally with a constructive approach, which I applaud, given how polarized the debates can be.”

Constructive? As I’ve pointed out repeatedly, no organization has been more effective at working the anti-TNR pseudoscience into a message neatly packaged for the mainstream media, and eventual consumption by the general public. (The Wildlife Society, though, which shares ABC’s penchant for bumper-sticker science and public discourse via sound-bites, is at least as eager to participate in the witch-hunt.)

Among the more glaring examples: senior policy advisor, Steve Holmer’s claim, quoted in the Los Angeles Times, that “there are about… 160 million feral cats [nationwide]” [12]; ABC’s promotion of “Feral Cats and Their Management,” with its absurd $17B economic impact “estimate,” published last year by the University of Nebraska-Lincoln; and the numerous errors, exaggerations, and misrepresentations that persist in their brochure Domestic Cat Predation On Birds and Other Wildlife (PDF)—including a rather significant blunder that Ellen Perry Berkeley brought to light seven years ago in her book TNR Past, Present and Future. [13]

A constructive approach begins, by necessity, with sound science. But when it comes to the issue of free-roaming cats, at least, ABC has demonstrated neither an interest nor an aptitude.

So how does such an organization end up as the sole resource listed in a widely-used undergraduate textbook? (One written by the same man who served as the National Audubon Society’s chief scientist from 1996 to 2005, no less.) What’s next—physiology and nutrition books directing students to the PepsiCo Website for their hydration lesson? Psychology texts deferring to Pfizer (makers of Zoloft) on selective serotonin reuptake inhibitors?

Frank Gill’s View
Gill never responded to my follow-up questions for this post. Still, his comments during our first exchange shed some light on his general attitude toward cats. “I have owned some wonderful (Siamese) cats in my life,” Gill explained, “so I do view them positively in many ways. But when they are dumped near a research station by returning vacationers and then eat the ringed birds I have been studying for many years, I take a different view.”

He followed this last sentence with a smiley-face emoticon, though the joke was clearly wasted on me.

“My informal view now is that managed feral cat colonies are potentially a serious threat to local bird populations, including both migrants that stopover in urban parks and endangered shorebird colonies. Sustaining those colonies should be prohibited generally. The return of coyotes to suburban landscapes is most welcome both to add a top predator to these ecosystems and to counter the numbers of feral cats as well as other midsized predators that impact breeding productivity. Just their presence in a neighborhood should persuade cat owners to keep their cats safely inside!”

•     •     •

It would be a mistake to suggest that the sloppy, flawed research I spend so much time critiquing can be traced directly to the second or third editions of Frank Gill’s textbook. Still, for many students, the path to a degree in ornithology (and onto related graduate degrees) leads through the book of the same name. As such, Ornithology may well be their first exposure to issues of population dynamics, conservation, and the like.

First impressions tend to be lasting ones. If, as a wide-eyed undergraduate, you “learned” that cats kill up to four million songbirds every day, how might that shape your future studies? Your career? What if you “learned” that such predation takes a $17B toll on the country annually?

Considering the tremendous burden we’re placing on future generations, why would we hobble them—before they even get started, really—with such misinformation and bias? They’ve got more than enough on their plate without having to fact-check their textbooks, too.

Literature Cited
1. Gill, F.B., Ornithology. 1st ed. 1990, New York: W.H. Freeman and Company. 660.

2. Banks, R.C., Special Scientific Report—Wildlife No. 215. 1979, United States Department of the Interior, Fish and Wildlife Service: Washington, DC. p. 16.

3. Stallcup, R., “A reversible catastrophe.” Observer 91. 1991(Spring/Summer): p. 8–9. http://www.prbo.org/cms/print.php?mid=530

http://www.prbo.org/cms/docs/observer/focus/focus29cats1991.pdf

4. Gill, F.B., Ornithology. 2nd ed. 1995, New York: W.H. Freeman and Company.

5. Perry, G. Cats—perceptions and misconceptions: Two recent studies about cats and how people see them. in Urban Animal Management Conference. 1999.

6. Millwood, J. and Heaton, T. The metropolitan domestic cat. in Urban Animal Management Conference. 1994.

7. Fitzgerald, B.M., Diet 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. 1988, Cambridge University Press: Cambridge; New York. p. 123–147.

8. Fitzgerald, B.M., “Is Cat Control Needed to Protect Urban Wildlife? Environmental Conservation. 1990. 17(02): p. 168-169. http://dx.doi.org/10.1017/S0376892900031970

9. Gill, F.B., Ornithology. 3rd ed. 2007, New York: W.H. Freeman. xxvi, 758 p.

10. Coleman, J.S., Temple, S.A., and Craven, S.R., “Cats and Wildlife: A Conservation Dilemma.” 1997. http://forestandwildlifeecology.wisc.edu/wl_extension/catfly3.htm

11. 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. www.vacadsci.org/vjsArchives/v43/43-1B/43-197.pdf

12. Yoshino, K. (2010, January 17). A catfight over neutering program. Los Angeles Times, from http://www.latimes.com/news/local/la-me-feral-cats17-2010jan17,0,1225635.story

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

Fantasy Islands

Thirty-three: that’s how many species of birds have been driven to extinction by feral cats. At least.

I’ve lost track of how many times I’ve stumbled across references to this figure over the past couple years. Not once, however, have I seen more than one species (usually the Stephens Island Wren, its story having been twisted into mythology over the years) mentioned as an example.

Which species? From where? Under what circumstances?

I seemed to be the only one interested in these questions. Indeed—as is often the case with such “facts”—the impact of the 33 extinctions reference increases the further it’s separated from its original context.

Recent Sightings
The most recent reference comes from Kiera Butler’s article in the July/August issue of Mother Jones. Domestic cats, Butler writes, are “responsible for at least 33 avian extinctions worldwide.” [1]

The authors of Feral Cats and Their Management, published last year by the University of Nebraska-Lincoln, qualified the role of cats somewhat: “While loss of habitat is the primary cause of species extinctions, cats are responsible for the extinction of at least 33 species of birds around the world.” [2]

Nico Dauphine mentioned the 33 extinctions in her now-infamous “Apocalypse Meow” presentation, and in her 2009 Partners In Flight paper, co-written with Robert Cooper: “Historically, cats have been specifically implicated in at least 33 bird extinctions, making them one of the most important causes of bird extinctions worldwide (Nogales et al. 2004).” [3]

In “A Review of Feral Cat Eradication on Islands,” Nogales et al. explain: “Feral cats are responsible for the extinction of at least 33 bird species. Insular endemic landbirds are most frequently driven to extinction.” [4, emphasis mine]

So we’re talking about islands? That’s no small distinction, as Fitzgerald and Turner make clear in their contribution to The Domestic Cat: The biology of its behaviour:

“Cats have become established within the last century or two on many oceanic islands that, by the nature of their origin, had very few if any mammals but possessed avian faunas that had evolved without mammalian predators. In these circumstances, cats have had severe effects, that were often combined with the effects of other introduced mammals and habitat modification.” [5]

In Search Of 33 Extinctions
As their source, Nogales et al. cite a 1994 book by Christopher Lever, Naturalized animals: The ecology of successfully introduced species, which in turn points us to a 1977 text:

“According to Jackson (1977), naturalized predators have collectively been responsible for the extermination throughout the world of no fewer than 61 avian taxa, the principal culprits being feral domestic Cats which have caused 33 extinctions, rats 14, and the Small Indian Mongoose nine. These are in addition to the numerous occasions of local extinctions.” [6]

Now we’re getting somewhere. Jackson provides a bar chart illustrating the “Relative importance of causes of avian extinctions since 1600; data are summarized from Ziswiler (1967).” [7]

Now, a truly thorough search wouldn’t end with Ziswiler’s work—as he cites four additional sources. Nevertheless, Ziswiler provides what I was looking for: the various species that were driven to extinction, their location, and an approximate date.

And—just as important—the various other factors that acted in combination with predation by cats (which Ziswiler lists in what appears to be hierarchical order, though it’s not entirely clear).

That’s right: not only are these extinctions limited to island habitats, they typically involve two or three contributing factors. In fact, of the 33 extinctions tabulated by Ziswiler, only eight are attributed to cats exclusively (and it turns out some of those have been “overturned” in the 44 years since Ziswiler first published his list, as we’ll see shortly).

All of which is pretty difficult to reconcile with, say, Butler’s straightforward indictment: cats are “responsible for at least 33 avian extinctions worldwide.” [1]

Cats and Avian Extinctions
Of the eight extinctions Ziswiler attributes to cats alone, just two have stood the test of time: the Stephens Island Wren and the Macquarie Island kakariki (red-crowned parakeet), as described below.

  • Stephens Island Wren (Xenicus lyalli; Traversia lyalli)
    Location: Stephens Island
    Cause (Ziswiler): feral cats
    What we know now: “Traversia lyalli is only known from recent times from Stephen’s Island, New Zealand, although it is common in fossil deposits from both of the main islands. It is not thought to have existed beyond 1894… Construction of a lighthouse on Stephens Island in 1894 led to the clearance of most of the island’s forest, with predation by the lighthouse keeper’s cat delivering the species’ coup-de-grace.” (BirdLife International)

    In fact, the story of the “lighthouse keeper’s cat” is only partly accurate.

    Drawing upon “archival and museum records,” Galbreath and Brown found that, contrary to popular accounts, it was not a single cat, but “a small population of cats… preying on the birds and other life of the island.” [8]

    “They had a considerable impact on the land birds of the island: the flightless Traversia lyalli was only the first to disappear. Judging by the numbers of specimens obtained in 1894 and subsequent years, the species was reduced considerably in that first year and eliminated entirely within perhaps a few more years. Extermination was rapid, although probably not as rapid as usually stated, nor by a single cat. But although the extinction of the Stephens Island wren may not have been quite as dramatic as it has usually been portrayed, it was tragic enough. Traversia lyalli was only one of the casualties of human exploitation of Stephens Island, which could, with just a little more care, have remained a safe haven for this and other species now entirely extinct.” [8]

  • Macquarie Island kakariki (Cyanoramphus novaezelandiae erythrotis)
    Location: Macquarie Island
    Cause (Ziswiler): feral cats
    What we know now: “For 70 years following the discovery of Macquarie Island in 1810 the endemic parakeet Cyanoramphus novaezelandiae erythrotis remained plentiful, despite the introduction of cats (Felis catus) and other predators. The crucial factor in the bird’s rapid disappearance between 1881 and 1890 appears to have been the successful liberation of rabbits (Oryctolagus cuniculus) in 1879. This led to great increases of feral cats and introduced wekas (Gallirallus australis) and presumably to greatly intensified predation on parakeets.” [9]

    Macquarie Island provides an interesting footnote: A 15-year cat eradication effort on the island, a United Nations Educational, Scientific and Cultural Organization World Heritage Site, concluded in 2000 with “unintended consequences [that] have been dire.” In the absence of cats, the population of rabbits and rodents has skyrocketed, prompting the Australian government to commit AU$24 million to further eradication efforts. [10]

Other Factors
Three of the other six cat-caused extinctions described by Ziswiler actually involve a host of factors, as revealed by 44 years of additional research

  • Guadalupe storm petrel (Oceanodroma macrodactyla)
    Location: Guadalupe
    Cause (Ziswiler): feral cats
    What we know now: “The main cause of its demise is thought to be heavy predation by feral cats, compounded by goats destroying and degrading nesting habitat.” However, “it cannot yet be presumed to be Extinct because there have been no thorough surveys of this difficult-to-detect species in the appropriate season since 1906, and relatively recent reports of unidentified storm-petrels calling at night, plus the persistence of Leach’s Storm-petrel breeding on the island provide some hope that it may survive. Any remaining population is likely to be tiny, and for these reasons it is treated as Critically Endangered (Possibly Extinct).” (BirdLife International)
  • Choiseul crested pigeon (Microgoura meeki)
    Location: Choiseul Island
    Cause (Ziswiler): feral cats
    What we know now: “Its extinction was presumably caused by predation by feral dogs and cats, as suitable habitat survives on the island… It has not been recorded since 1904 despite searching and interviews with villagers.” (BirdLife International)
  • Bonin crested pigeon (Comumba versicolor)
    Location: Bonin Islands
    Cause (Ziswiler): feral cats
    What we know now: “Its extinction presumably resulted from clearance of the islands’ subtropical evergreen forest, and from predation by introduced cats and rats… It was last recorded in 1889.” (BirdLife International)

Natural Disaster
The case of the St. Christopher Bullfinch is intriguing in that cats may not have been involved at all.

  • St. Christopher Bullfinch (Loxigilla portoricensis grandis)
    Location: St. Christopher Island
    Cause (Ziswiler): feral cats
    What we know now: In 1979, Herbert Raffaele offered an explanation that makes no mention of cats whatsoever, picking up the story where James Greenway [11], one of the sources cited by Ziswiler, left off:

    “The only explanation yet put forward for the extinction of L. p. grandis is that of Bond (1936, 1956), who suggested the bird’s demise resulted from heavy predation by Green Monkeys (Cercopithecus aethiops) which were introduced on St. Kitts. Greenway (1958) noted that this hypothesis appears weak because the related Lesser Antillean Bullfinch (L. noctis) has survived disturbance by the same monkeys on Barbados (indeed, L. noctis thrives on St. Kitts itself); he further suggested that “Other unknown factors may have been involved.” Greenway, however, did not propose an alternative hypothesis. I shall examine the often-quoted monkey hypothesis and suggest an alternative explanation.” [12]

    Readers interested in the details of the “often-quoted monkey hypothesis” will want to download the PDF. The short answer is: two hurricanes during August 1899 were “probably enough to eliminate L. p. grandis.” [12]

Extinction Is (Not) Forever
Perhaps the most surprising finding, though, is that two of the species Ziswiler claims were driven to extinction by feral cats—the Aukland Islands rail and the Eyrean grass-wren—turn out not to be extinct at all.

  • Aukland Islands rail (Rallus muelleri; Lewinia muelleri)
    Location: Aukland Islands
    Cause (Ziswiler): feral cats
    What we know now: “It was once thought to be extinct but was rediscovered on Adams Island (100 km2) in 1966 and Disappointment Island (4 km2) in 1993… Population numbers are apparently stable.  Although both rail-inhabited islands are predator-free, Auckland Island (a few hundred metres from Adams) supports feral cats, mice and pigs, and therefore the introduction of these animals is a possible threat.” (BirdLife International)
  • Eyrean grass-wren (Amytornis goyderi)
    Location: Australia
    Cause (Ziswiler): feral cats
    What we know now: “Although this species may have a restricted range, it is not believed to approach the thresholds for Vulnerable under the range size criterion… the population trend criterion… [or] the population size criterion… For these reasons the species is evaluated as Least Concern.” (BirdLife International)

Plenty of Blame to Go Around
The remaining 25 extinctions, while not as dramatic as some of those already mentioned, illustrate very well complexities generally lost to those who blindly cite the 33 extinctions (reason enough, they seem to argue, to outlaw the feeding of feral cats and TNR programs everywhere).

  • Iwo Jima rail (Poliolimnas cinereus brevipes)
    Location: Iwo Jima
    Cause (Ziswiler): rats and feral cats
    What we know now: “Due to an increasing human population on Naka from 1910 onwards, its habitat degraded, and natural water sources became scarce. Therefore, the birds had to depend on water tanks near houses in the dry season, where they were easily caught by feral or domestic cats. The last birds collected for science were in 1911 (the 12 birds of the type-series of brevipes), and the last bird seen was in 1920–1925 (Greenway 1967).” (Zoological Museum Amsterdam)

  • Bonin night heron (Nycticorax caledonicus crassirostris)
    Location: Bonin Islands
    Cause (Ziswiler): “habitat altered through civilization or monocultures” and feral cats
    What we know now: “The most likely reason for its extinction is predation by rats and feral cats. However, collectors fascinated by its plumes may also have been responsible; birds shot for use in millinery (a burgeoning business in contemporary Japan) would not have ended up in scientific collections… The Bonin Night Heron became extinct only 50 years after its description. The last specimen was taken in 1889 on Nakōdo-jima.” (Wikipedia)
  • Red-billed rail (Rallus pacificus)
    Location: Tahiti
    Cause (Ziswiler): rats and feral cats
    What we know now: “It was flightless, and its extinction was presumably caused by introduced cats and rats… there were reports from Tahiti until 1844, and from the nearby Mehetia until the 1930s.(BirdLife International)
  • Chatham Island banded rail (Rallus dieffenbachii)
    Location: Chatham Island
    Cause (Ziswiler): feral cats and rats
    What we know now: “Its extinction was presumably due to predation by introduced rats, cats and dogs, and habitat loss from fire… The species was already scarce when the type was collected in 1840, and was extinct by 1872.” (BirdLife International)
  • Samoa wood rail (Pareudiastes pacificus; Gallinula pacifica)
    Location: Samoa
    Cause (Ziswiler): feral cats and rats
    What we know now: “Cats, rats, pigs and dogs have no doubt contributed to its disappearance, and hunting may also have been a factor as it was formerly a favoured food of the human population… it was last recorded in 1873. In 1984 there were two possible sightings in upland forest west of Mt Elietoga, and in October 2003 a possible sighting of two individuals was made at 990 m on Mount Sili Sili. A recent survey of the island yielded no record of the species.” (BirdLife International)
  • Jamaica Pauraque (Siphonornis americanus americanus; Siphonorhis americana)
    Location: Jamaica
    Cause (Ziswiler): feral cats and “mongoose forms”
    What we know now: “This species has not been recorded since 1860, and it may have been driven to extinction by introduced mongooses and rats, whose effect may have been exacerbated by habitat destruction. However, it cannot yet be presumed to be Extinct because there have been recent unconfirmed reports, and surveys may possibly have overlooked this nocturnal species. Any remaining population is likely to be tiny, and for these reasons it is treated as Critically Endangered (Possibly Extinct).” (BirdLife International)

    Note: there is no mention of cats at all.

  • Lord Howe grey-headed blackbird (Turdus poliocephalus vinitinctus)
    Location: Lord Howe Island
    Cause (Ziswiler): feral cats and feral pigs
    What we know now: “It was quite common in 1906 but its population began to diminish in 1913 due to disturbance by man, cats, dogs, goats and feral pigs. When the SS Makambo was shipwrecked on Lord Howe in June 1918 rats escaped from the vessel and overran the island. With other endemic bird species this ground-nesting bird became extinct within six years.” (Wikipedia)
  • Raiatea thrush (Turdus ulietensis)
    Location: Society Islands
    Cause (Ziswiler): feral cats and rats
    What we know now: “Raiatea was visited in 1850 by explorer and natural history collector Andrew Garrett, who failed to record the species. Evidently it became extinct between 1774 and 1850, almost certainly as a consequence of the inadvertent introduction of Black or Brown Rats to the island.” (Wikipedia)

    Again, no mention of cats.

  • Kittlitz’s thrush (Zoothera terrestris)
    Bonin Islands
    Cause (Ziswiler): feral cats and rats
    What we know now: “Whalers started to use the island in the 1830s and it was probably driven to extinction by introduced rats and cats shortly after.” (BirdLife International)
  • Hawaiian honeycreepers (16 forms)
    Location: Hawaii
    Cause (Ziswiler): “habitat altered through destruction of the forest,” “habitat altered through civilization or monocultures,” and feral cats
    What we know now: “Some 20 species of Hawaiian honeycreeper have become extinct in the recent past, and many more in earlier times, between the arrival of arrival of the Polynesians who introduced the first rats, chickens, pigs, dogs, and hunted and converted habitat for agriculture.” (Wikipedia)

    Also: “The birds face a host of hungry new arrivals such as rats, cats, and pigs, as well as the age-old problem of habitat destruction. But their main enemy was the arrival of avian malaria in the 1940s.” (The Cornell Lab of Ornithology)

•     •     •

So, how many avian extinctions have cats caused? I don’t know.

Then again, neither do Butler, the authors of the UNL paper, Dauphine, or any of the others who suggest they do—and then use that “knowledge” to fuel the witch-hunt against free-roaming cats.

It’s funny how the same people who make so much noise about the U.S. population of pet cats tripling over the past 40 years (without acknowledging the increasing likelihood that these cats are indoor-only, of course) have demonstrated no interest at all in updating their island extinctions factoid.

Then again, they only rarely acknowledge the fact that the extinctions occurred on islands, or the fact that feral cats were just one of many contributing factors. In those instances where cats were involved at all—and where birds were actually driven to extinction.

Considering what these people are proposing—the wholesale killing of cats by the tens of millions—is it really too much to ask that they do a little more fact-checking and a little less Kool-Aid drinking?

Literature Cited
1. Butler, K., “Faster, Pussycat! Kill! Kill!” Mother Jones. 2011. July/August. p. 72–73.

2. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

3. Dauphine, 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. http://www.pwrc.usgs.gov/pif/pubs/McAllenProc/articles/PIF09_Anthropogenic%20Impacts/Dauphine_1_PIF09.pdf

4. Nogales, M., et al., “A Review of Feral Cat Eradication on Islands.” Conservation Biology. 2004. 18(2): p. 310–319. http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2004.00442.x/abstract

5. 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.

6. Lever, C., Naturalized animals: The ecology of successfully introduced species. 1994, London: T & A.D. Poyser Natural History.

7. Jackson, J.A., Alleviating Problems of Competition, Predation, Parasitism, and Disease in Endangered Birds: A Review, in Endangered Birds: Management Techniques for Preserving Threatened Species, S.A. Temple, Editor. 1977, The University of Wisconsin Press: Madison. p. 75–84.

8. Galbreath, R., “The tale of the lighthouse-keeper’s cat: Discovery and extinction of the Stephens Island wren (Traversia lyalli).” Notornis. 2004. 51: p. 193–200.

9. Taylor, R.H., “How the Macquarie Island Parakeet Became Extinct.” New Zealand Journal of Ecology. 1979. 2: p. 42–45. www.nzes.org.nz/nzje/free_issues/NZJEcol2_42.pdf

10. Bergstrom, D.M., et al., “Indirect effects of invasive species removal devastate World Heritage Island.” Journal of Applied Ecology. 2009. 46(1): p. 73–81. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2008.01601.x/abstract

http://eprints.utas.edu.au/8384/4/JAppEcol_Bergstrom_etal_journal.pdf

11. Greenway, J.C., Extinct and vanishing birds of the world. 1958, American Committee for International Wild Life Protection.

12. Raffaele, H.A., “Comments on the extinction of Loxigilla portoricensis grandis in Saint Kitts.” Condor. 1977. 79: p. 389–390. elibrary.unm.edu/sora/Condor/files/issues/v079n03/p0389-p0390.pdf

Feral Cats: The Next Stimulus Package?

According to a recent story in Forbes, many of the expenses associated with caring for feral cats are tax-deductible.

A family lawyer who devoted most of her time outside of work to caring for feral cats, 70 to 80 at one time, in her Oakland, Calif. home is entitled to much of her claimed $12,068 in cat care expenses as a charitable deduction on her 2004 income taxes, according to a recent Tax Court case. Basically, the case says that unreimbursed volunteer expenses, to the extent they are incidental to charitable work for a qualified charity and are properly substantiated, are deductible.

Adjusting for inflation, that’s $13,810.94, or about $184 per cat. Multiply that by the 60–120 million feral cats the American Bird Conservancy claims are in the U.S. [1], and we’re talking real money: $11.0–22.1 billion annually.

Voodoo Economics
Suddenly, the $17 billion “economic impact” suggested by the authors of “Feral Cats and Their Management” [2] seems decidedly less impressive. Not that it was ever credible, of course—especially given the dubious quality of several underlying assumptions. The now-mythical “estimate,” which originated with David Pimentel, Professor Emeritus at Cornell, is a mix of proofiness and careless mistakes.

None of which prevented it from making headlines around the world beginning in December of last year. Endorsements from the National Audubon Society and American Bird Conservancy were immediate.

(For a thorough review of the $17B figure, please see Laurie Goldstein’s “17 Reasons the Economic Impact of the Domestic Cat as a Non-Native Species in the U.S. Does Not Cost $17 Billion.” Had Pimentel been half as careful as Goldstein, he might have had something worth publishing.)

Life Is Cheap(er)
Actually, $184 per cat is probably conservative.

No doubt Jan Van Dusen—because she used her home as a shelter—incurred expenses many of us do not. But she probably didn’t spend nearly as much on gasoline and other transportation-related items. And, she didn’t have to worry about cold-weather accommodations.

Then there’s the expense Van Dusen saved her community—let’s call it $6,500—for not having the cats impounded and euthanized killed. That’s based on a cost of $87 per cat, an estimate generated by the Volusia County (FL) Animal Control Advisory Board.

Combining Van Dusen’s per-cat expense with the $87 savings, and we’re up to $271 per cat. Multiply that by ABC’s 60­–120 million cats for a total of $16.3–32.5 billion annually. That’s a decent shot in the arm for an economy in trouble, and there’s no time like the present.

While we’re at it, why not a WPA-style program to put Americans to work caring for feral cats?

Absurd? Obviously.

The difference, of course, is that—unlike the authors of the UNL paper, Pimentel, ABC, and so many others—I’m not presenting my numbers as if they’re not absurd.

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

2. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

Going Native

Two Archaeological photosEvidence of cats as pets? In Cyprus, 9,500 years ago (left) and, 3,500 years ago, in Peru (right).

As reported in yesterday’s New York Times, the history of the domestic cat is being rewritten—yet again. (Whether this piece gets the same attention as Elisabeth Rosenthal’s “Tweety Was Right” story remains to be seen—and I, for one, am not holding my breath.)

Arrivals and Departures
For years now, there has been some debate surrounding the arrival of cats in North America. Some have argued that cats were brought over by the Vikings (which might explain the resemblance between Norwegian Forest cats and Maine Coons [1]), while others have suggested that cats first arrived with Christopher Columbus or—roughly 100 years later—with the original settlers of Jamestown. [2]

A 2009 article in Scientific American demonstrated the uncertainly surrounding this issue in one of its illustrations: “Americas: 500 years ago?” [2]

Recent research, however, is challenging such estimates in a big way.

Working in the New Mexican desert, a team of archaeologists was shocked to find evidence of what appear to be domestic cats dating back to the late Archaic Period (roughly 8000 to 2000 BC). This, noted one of the researchers, isn’t entirely unexpected—it’s generally accepted that cats “sort of domesticated themselves” in response to the rise of agriculture elsewhere in the world. [3]

Even there, the story has been changing:

“Scholars long believed that the ancient Egyptians were the first to keep cats as pets, starting around 3,600 years ago. But genetic and archaeological discoveries made over the past five years have revised this scenario—and have generated fresh insights into both the ancestry of the house cat and how its relationship with humans evolved.” [2]

Indeed, a 2007 paper in Science made headlines when the authors, using DNA evidence, demonstrated that “the earliest evidence of cat-human association involves their co-occurrence in Cyprus deposits determined to be 9500 years old.” [3]

Closer to home: just last year, a site in Peru revealed that cats were being domesticated 3,500 years ago in the country’s ancient Lambayeque region.

Name-Calling
All of which raises the question: What’s the difference between native and non-native species?

Well, if you’re a domestic cat, it might just be the difference between life and death. “The claim that the cat’s exotic status should count against it often is employed in policy arguments about cats as a conversation-stopper,” writes Cornell’s James Tantillo, “that the cat is an exotic ‘alien’ is supposed to trump all other values in the debate.” [4]

For TNR opponents, it’s the gift that keeps on giving:

  • In a recent news release, the American Bird Conservancy describes the domestic cat as “a highly efficient non-native predator.”
  • The Wildlife Society, publisher of The Wildlife Professional, refers repeatedly to cats as “non-native” and “invasive” in a special section of its Spring Issue called “The Impact of Free Ranging Cats.”

Still, none provides anything by way of a definition or objective measure.

In his provocative 1998 essay, “Nativism and Nature: Rethinking biological invasion,” Jonah Peretti argues, “it is unclear how long a species needs to be established in a location before it is considered native. Is a species ‘naturalised’ in 100 years, 1,000 years, or 10,000 years? The distinctions are arbitrary and unscientific.” [6]

“Nativist trends in Conservation Biology have made environmentalists biased against alien species. This bias is scientifically questionable, and may have roots in xenophobic and racist attitudes. Rethinking conservationists’ conceptions of biological invasion is essential to the development of a progressive environmental science, politics, and philosophy.” [6]

Us and Them
The biases Peretti refers to are remarkably selective.

Where’s the outcry against honeybees, for example, which originated in South and Southeast Asia? “In many places,” suggests Mark Sagoff, “one can hardly imagine the landscape without alien species.” [7]

“Virtually everything down on the farm is an exotic: of all crops, only sunflowers, cranberries, and Jerusalem artichokes evolved in North America. Corn, soybeans, wheat, and cotton have been imported from some other land. Cattle came from Europe. Rockfish—or striped bass as they are known outside Maryland—are native to the Bay but have been introduced up and down the Atlantic and Pacific coasts for sport and commercial fishing. More than 90 percent of all oysters sold in the world are produced by aquaculture, and almost the entire oyster industry on the West Coast is based on a species imported from Japan.” [7]

Our very identities can be wrapped up in what is, in fact, alien, notes Sagoff. “Kentucky identifies itself as the ‘Bluegrass State,’ but bluegrass immigrated from England.” [7]

And immigrants, Sagoff points out, are—broadly speaking—often unwelcome.

“…those who seek funds to exclude or eradicate non-native species often attribute to them the same disreputable qualities that xenophobes have attributed to immigrant groups. These undesirable characteristics include sexual robustness, uncontrolled fecundity, low parental involvement with the young, tolerance for ‘degraded’ or squalid conditions, aggressiveness, predatory behavior, and so on.” [7]

I don’t know if I’m willing to go that far—and yet the parallels are both undeniable and striking. (“Feral Cats and Their Management,” don’t forget, was still trying to sell the idea—debunked long ago—that “a pair of breeding cats and their offspring can produce over 400,000 cats in seven years” [8] as recently as late 2010)

“The exotic issue,” argues Tantillo, “raises the philosophical problem known as the ‘is-ought’ problem: form a descriptive statement of what is, it is logically invalid to conclude automatically from that fact to what ought to be the case without some type of intervening moral argument.” [4]

For many, what ought to be the case is the idyllic past—as exemplified in the Leopold Report, which lay out the vision for the country’s national parks:

“As a primary goal, we would recommend that the biotic associations within each park be maintained, or where necessary recreated, as nearly as possible in the condition that prevailed when the area was first visited by the white man. A national park should represent a vignette of primitive America.”

As Peretti points out, however, primitive America is not only irretrievable; it’s also a myth.

“It is assumed that Europeans found the Americas in a pristine, natural state. The goal of management is to protect and recreate native nature, before it was altered, invaded, and degraded by European culture and European biota. This perspective often relies on an idealised and patronising attitude toward Native Americans… Many anthropologists and archaeologists challenge the view that Native Americans lived in perfect harmony with nature. Rather, they assert that Native American hunters were responsible for the extinction of the bulk of the Pleistocene megafauna. By the time Europeans arrived, most of these native species had already gone extinct. [6]

Re-writing History?
So, what if cats were here long before Europeans arrived? What if the domestic cat has actually been—as these recent discoveries indicate—in North America for 4,000 or 5,000 years? Or 10,000 years?

This changes everything, doesn’t it?

Well, it might on any other day of the year. On April 1st, though, it changes nothing—because it’s simply an April Fools’ fabrication (though nearly all of the “supporting evidence” is, I hasten to point out, completely accurate).

Unfortunately, even if such news were true, it’s difficult to imagine it making the slightest difference to TNR opponents—for whom the whole non-native argument is neither biologically nor philosophically based. It’s simply a red herring.

Take that away from them, and they’ll just find something else.

Literature Cited
1. Tabor, R., Cats—The Rise of the Cat. 1991, London: BBC Books.

2. Driscoll, C.A., et al., The Taming of the Cat, in Scientific American. 2009. p. 68–75. http://www.scientificamerican.com/article.cfm?id=the-taming-of-the-cat

3. Driscoll, C.A., et al., “The Near Eastern Origin of Cat Domestication.” Science. 2007. 317(5837): p. 519-523. http://www.sciencemag.org/content/317/5837/519.abstract

4. Tantillo, J.A., Killing Cats and Killing Birds: Philosophical issues pertaining to feral cats, in Consultations in Feline Internal Medicine Volume 5, J.R. August, Editor. 2006, Elsevier Saunders: St. Louis, MO. p. 701–708.

5. 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. http://www.abcbirds.org/abcprograms/policy/cats/pdf/Management_claims_feral_cats.pdf

6. Peretti, J.H., “Nativism and Nature: Rethinking biological invasion.”Environmental Values. 1998. 7: p. 183–192. http://www.erica.demon.co.uk/EV/EV710.html

7. Sagoff, M., What’s Wrong with Exotic Species? 1999, Institute for Philosophy and Public Policy. https://scholar.vt.edu/access/content/user/hullrb/PUBLIC/sagoffexoticspecies.pdf

8. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

It’s Not the Media, It’s the Message

To hear The Wildlife Society’s staunch opponents of TNR tell it, the media’s just not interested in stories about “the impacts of free-ranging and feral cats on wildlife.”

“This January when thousands of blackbirds fell from the sky in Arkansas, articles about mass extinctions and bird conservation were a dime-a-dozen. When the Deepwater Horizon oil spill killed 6,000 birds between April to October 2010, news organizations ran ‘Breaking News’ about the negative impacts on the environment. Meanwhile it is estimated that one million birds are killed everyday by cats, and the only news organizations covering it are small, local branches. The bigger problem is being shuffled to the backburner for more sensational news.”

According to The Wildlife Society (TWS), however, “the bigger problem” is “greater than almost any other single-issue.”

In their effort to get the issue on the front burner, TWS has “gathered the facts about these cats, and published them in the Spring Issue of The Wildlife Professional in a special section called ‘The Impact of Free Ranging Cats.’” (available free via issuu.com)

Thus armed, readers are expected to, as it says on the cover, “Pick One: Outdoor Cats or Conservation”

Back Burner or Hot Topic?
Before we get to the “facts,” it’s worth looking back over the past 15 months to see just how neglectful the media have been re: “the bigger problem.”

  • January 9, 2010: Travis Longcore, science director for the Urban Wildlands Group, tells Southern California Public Radio: “Feral cats are documented predators of native wildlife. We do not support release of this non-native predator into our open spaces and neighborhoods, where they kill birds and other wildlife.”
  • January 17, 2010 Longcore, whose Urban Wildlands Group was lead plaintiff in a lawsuit aimed to put an end to publicly supported TNR in Los Angeles, tells the L.A. Times: “It’s ugly; it’s gotten very vicious. It’s not like we’ve got a vendetta here. This is a real environmental issue, a real public health issue.” In the same story, American Bird Conservancy’s Senior Policy Advisor, Steve Holmer, tells the Times: “The latest estimates are that there are about . . . 160 million feral cats [nationwide]… It’s conservatively estimated that they kill about 500 million birds a year.”

  • September 30, 2010: “Scientists are quietly raging about the effects that cats, both owned and stray, are having on bird populations,” claims Washington Post columnist Adrian Higgins. “It’s not an issue that has received much attention, but with an estimated 90 million pet cats in the United States, two-thirds of them allowed outdoors, the cumulative effect on birds is significant, according to experts.” Higgins’ story is riddled with misinformation, courtesy of the American Bird Conservancy (ABC), The Wildlife Society, and Dauphine and Cooper’s 2009 Partners in Flight paper.

“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.” (A claim easily discredited, if only the reporters had bothered to check.)

  • January 2011: Utah Representative Curtis Oda sponsors HB 210, which would permit “the humane shooting of an animal in an unincorporated area of a county, where hunting is not prohibited, if the person doing the shooting has a reasonable belief that the animal is a feral animal.”

Yet, the folks at TWS would have us believe that “the only news organizations covering [the cat-bird issue] are small, local branches.” As is often the case, their story doesn’t hold up well alongside the facts.

Indeed, other than when Higgins got Executive Director/CEO Michael Hutchins’ name wrong, it’s hard to see what TWS has to complain about.

The Art of Selling Science
“After years of arguments,” laments Nico Dauphine and Robert Cooper, recalling last year’s decision by Athens, GA, to adopt TNR, “the vote was cast: 9–1 in favor of the ordinance, with an additional 7–3 vote establishing a $10,000 annual budget to support the TNR program.”

“How could this happen in a progressive community like Athens, Georgia, home to one of the nation’s finest university programs in wildlife science? The answer is a complex mix of money, politics, intense emotions, and deeply divergent perspectives on animal welfare… If we’re going to win the battle to save wildlife from cats, then we’ll need to be smarter about how we communicate the science.” [1]

Something tells me this “smarter” communication doesn’t allow for much in the way of honesty and transparency—attributes already in short supply.

Old Habits
“The Impact of Free Ranging Cats” has given its contributors the opportunity to revive and reinforce a range of dubious claims, including the ever-popular exaggerations about the number of free-roaming cats in the environment.

According to Dauphine and Cooper, “The number of outdoor pet cats, strays, and feral cats in the U.S. alone now totals approximately 117 to 157 million,” [1] an estimate rooted in their earlier creative accounting. Colin Gillin, president of the American Association of Wildlife Veterinarians, who penned this issue’s “Leadership Letter” (more on that later), follows suit, claiming  “60 million or more pet cats are allowed outdoors to roam free.” [2]

The American Pet Products Association 2008 National Pet Owners Survey, though, indicates that 64 percent of pet cats are indoor-only during the daytime, and 69 percent are kept in at night [3]. Of those that are allowed outdoors, approximately half are outside for less than three hours each day. [4, 5]

This information is widely available—and has been for years—yet many TNR opponents continue to inflate by a factor of two the number of free-roaming pet cats.

And it only gets worse from here.

Dense and Denser
Not content to inflate absolute cat numbers, Dauphine and Cooper go on to misrepresent research into population demographics as well. “Local densities can be extremely high,” they write, “reaching up to 1,580 cats per square kilometer in urban areas.” [1] In fact, the very paper they cite paints a rather different picture. For one thing, there’s quite a range involved: 132–1,579 cats per square kilometer (a point recognized by Yolanda van Heezik, another contributor to the special issue [6].)

Also, this is a highly skewed distribution—there are lots of instances of low/medium density, while high densities are far less common. As a result, the median (417) is used “as a measure of central tendency” [7] rather than the mean (856). So, although densities “reaching up to 1,580 cats per square kilometer in urban areas” were observed, more than half fell between 132 and 417 cats per square kilometer (or 51–161 cats per square mile).

Even more interesting, however, are what Sims et al. learned when they compared bird density and cat density: in many cases, there were more birds in the very areas where there were more cats—even species considered especially vulnerable to predation by cats. It may be, suggest Sims et al., that, because high cat density corresponds closely to high housing density, this measure is also an indication of those areas “where humans provide more supplementary food for birds.” [7]

Another explanation: “consistently high cat densities in our study areas… and thus uniformly high impacts of cat populations on urban avian assemblages.” [7] (Interestingly, the authors never consider that they might be observing uniformly low impacts.)

The bottom line? It’s difficult enough to show a direct link between observed predation and population impacts; suggesting a causal connection between high cat densities and declining bird populations is misleading and irresponsible. (Not that Dauphine and Cooper are the only ones to attempt it; recall that no predation data from Coleman and Temple’s “Wisconsin Study” were ever published, despite numerous news stories in which Temple referred to their existence in some detail [8–10].)

Predation Pressure
Dauphine and Cooper make a similar leap when, to buttress their claim that “TNR does not reduce predation pressure on native wildlife,” [1] they cite a study not about predation, but about the home ranges of 27 feral cats on Catalina Island.

While it’s true that the researchers found “no significant differences… in home-range areas or overlap between sterilized and intact cats,” [11] this has as much due to their tiny sample size as anything else. And the difference in range size between the four intact males and the four sterilized males was—while not statistically significant—revealing.

The range of intact males was 33–116 percent larger during the non-breeding season, and 68–80 percent larger during the breeding season. In his study of “house-bound” cats, Liberg, too, found differences: “breeding males had ranges of 350–380 hectares; ranges of subordinate, non-breeding males were around 80 hectares, or not much larger than those of females.” [12]

All of which suggests smaller ranges for males that are part of TNR programs. What any of this has to do with “predation pressure on native wildlife,” however, remains an open question.

On the other hand, Castillo and Clarke (whose paper Dauphine and Cooper cite) actually documented remarkably little predation among the TNR colonies they studied. In fact, over the course of approximately 300 hours of observation (this, in addition to “several months identifying, describing, and photographing each of the cats living in the colonies” [13] prior to beginning their research), Castillo and Clarke “saw cats kill a juvenile common yellowthroat and a blue jay. Cats also caught and ate green anoles, bark anoles, and brown anoles. In addition, we found the carcasses of a gray catbird and a juvenile opossum in the feeding area” [13].

Another of Dauphine and Cooper’s “facts”—that “TNR does not typically reduce feral cat populations”—is contradicted by another one of the studies they cite. Contrary to what the authors suggest, Felicia Nutter’s PhD thesis work showed that “colonies managed by trap-neuter-return were stable in composition and declining in size throughout the seven year follow-up period.” [14]

Indeed, Nutter observed a mean decrease of 36 percent (range: 30–89 percent) in the six TNR colonies they studied over two years. By contrast, the three control colonies increased in size an average of 47 percent. [15]

Additional TNR success stories Dauphine and Cooper fail to acknowledge:

  • Natoli et al. reported a 16–32 percent decrease in population size over a 10-year period across 103 colonies in Rome—despite a 21 percent rate of “cat immigration.” [16]
  • As of 2004, ORCAT, run by the Ocean Reef Community Associa­tion (in the Florida Keys), had reduced its “overall population from approximately 2,000 cats to 500 cats.” [17] Accord­ing to the ORCAT Website, the population today is approximately 350, of which only about 250 are free-roaming.

Toxoplasma gondii
In recent years, Toxoplasma gondii has been linked to the illness and death of marine life, primarily sea otters [18], prompting investigation into the possible role of free-roaming (both owned and feral) cats. [19, 20] But if, as the authors claim, “the science points to cats,” then it does so rather obliquely, an acknowledgement Jessup and Miller make begrudgingly:

“Based on proximity and sheer numbers, outdoor pet and feral domestic cats may be the most important source of T. gondii oocysts in near-shore marine waters. Mountain lions and bobcats rarely dwell near the ocean or in areas of high human population density, where sea otter infections are more common.” [21, emphasis mine]

Correlation, however, is not the same as causation. And not all T. gondii is the same.

In a study of southern sea otters from coastal California, conducted between 1998 and 2004, a team of researches—including Jessup and Miller—found that 36 of 50 otters were infected with the Type X strain of T. gondii, one of at least four known strains. [22] Jessup and Miller were also among 14 co-authors of a 2008 paper (referenced in their contribution to “The Impact of Free Ranging Cats”) in which the Type X strain was linked not to domestic cats, but to wild felids:

“Three of the Type X-infected carnivores were wild felids (two mountain lions and a bobcat), but no domestic cats were Type X-positive. Examination of larger samples of wild and domestic felids will help clarify these initial findings. If Type X strains are detected more commonly from wild felids in subsequent studies, this could suggest that these animals are more important land-based sources of T. gondii for marine wildlife than are domestic cats.” [20, emphasis mine]

Combining the results of the two studies, then, nearly three-quarters of the sea otters examined as part of the 1998–2004 study were infected with a strain of T. gondii that hasn’t been traced to domestic cats. (I found this to be such surprising news that, months ago, I tried to contact Miller about it. Was I missing something? What studies were being conducted that might confirm or refute these finings? Etc. I never received a reply.)

As Miller et al. note, “subsequent studies” are in order. And it’s important to keep in mind their sample size was quite small: three bobcats, 26 mountain lions, and seven domestic cats (although the authors suggest at one point that only five domestic cats were included).

Still, a recently published study from Germany seems to support the hypothesis that the Type X strain isn’t found in domestic cats. Herrmann et al. analyzed 68 T. gondii-positive fecal samples (all from pet cats) and found no Type X strain. [23] (It’s interesting to note, too, that only 0.25 percent of the 18,259 samples tested positive for T. gondii.)

This is not to say that there’s no connection between domestic cats and Toxoplasmosis in sea otters, but that any “trickle-down effect,” as Jessup and Miller describe it, is not nearly as well understood as they imply. There’s too much we simply don’t know.

Money and Politics
I agree with Dauphine and Cooper that science is only part of the TNR debate—that it also involves “a complex mix of money, politics, intense emotions, and deeply divergent perspectives on animal welfare.” And I agree with their assessment of the progress being made by TNR supporters:

“Advocates of TNR have gained tremendous political strength in the U.S. in recent years. With millions of dollars in donor funding, they are influencing legislation and the policies of major animal-oriented nonprofit organizations.” [1]

What I find puzzling is Dauphine’s rather David-and-Goliath portrayal of the “cat lobby” (my term, not hers) they’re up against—in particular, her complaint, “promotion of TNR is big business, with such large amounts of money in play that conservation scientists opposing TNR can’t begin to compete.” [24]

The Cat Lobby
In “Follow the Money: The Economics of TNR Advocacy,” she notes that Best Friends Animal Society, “one of the largest organizations promoting TNR, took in over $40 million in revenue in 2009.” [24] Fair enough, but this needs to be weighed against expenses of $35.6 million—of which $15.5 million was spent on “animal care activities.”

But Dauphine’s got it wrong when she claims that Best Friends “spent more than $11 million on cat advocacy campaigns that year.” [24] Their financials—spelled out in the same document Dauphine cites—are unambiguous: $11.7 million in expenditures went to all “campaigns and other national outreach.” Indeed, there is no breakdown for “cat advocacy campaigns.”

Dauphine does a better job describing Alley Cat Allies’ 2010 financials: of the $5.2 million they took in, $3.3 million was spent in public outreach. But she’s overreaching in suggesting that their “Every Kitty, Every City” campaign is nationwide. For now, at least, it’s up and running in just “five major U.S. cities.”

Echoing Dauphine’s concerns, Florida attorney Pamela Jo Hatley decries ORCAT’s resources: “At a meeting hosted by the Ocean Reef Resort in June 2004,” recalls Hatley, “I learned that the ORCAT colony then had about 500 free-ranging cats, several paid employees, and an annual operating budget of some $100,000.” [25]

What Hatley fails to mention is how those resources have been used to make ORCAT a model for the rest of the country—using private donations. Hatley doesn’t seem to object to the U.S. Fish and Wildlife Service shelling out $50,000—of tax dollars—in 2007 to round up fewer than 20 cats (some of which were clearly not feral) along with 81 raccoons (53 of which were released alive) in the Florida Keys. [26, 27]

Following the Money
According to their 2008 Form 990, ORCAT took in about $278,000 in revenue, compared to $310,000 in expenses. How does that compare to some of the organizations opposing TNR? A quick visit to Guidestar.com helps put things in perspective.

  • In 2009, ABC took in just under $6 million, slightly more than their expenses.
  • TWS had $2.3 million in revenue in 2009, which was more than offset by expenses of $2.5 million.
  • Friends of the National Zoo, which oversees the Smithsonian Migratory Bird Center, showed $15 million in revenue, just exceeding their 2009 expenses of $14.7 million. (The Smithsonian Institute topped $1 billion in both the revenue and expense categories.)
  • And the National Audubon Society took in $61.6 million in 2008 (the most recent year for which information is available). And, despite expenses in excess of $86 million, finished the year with more than $255 million in net assets.

These numbers clearly don’t reflect the funding each organization dedicates to opposing TNR—but neither do they offer any evidence that, as Dauphine argues, “conservation scientists opposing TNR can’t begin to compete.”

Intense Emotions
Nobody familiar with the TNR debate would suggest that it’s not highly emotional. How can it be otherwise? Indeed, the very idea of decoupling our emotions from such important discourse is rather absurd.

Having an emotional investment in the debate does not, however, make one irrational or stupid.

“On the surface,” suggest Dauphine and Cooper, their tone unmistakably condescending, “TNR may sound reasonable, even logical.” [1] Gillin, for his part, bemoans the way the TNR debate “quickly shifts from statistics to politics to emotional arguments.” [2]

What’s particularly fascinating about all of this—the way TNR supporters are made out to be irrational (if not mentally ill—as in a letter to Conservation Biology last year, when several TNR opponents, including four contributors to “The Impact of Free Ranging Cats,” compared TNR to hoarding [28])—is just how emotionally charged the appeal of TNR opponents is.

Witness the “gruesome gallery of images,” for example, in which “one cat lies dead with a broken leg, one lies dying in a coat of maggots, and another suffers as ticks and ear mites plague its face.” [1] The idea, of course, is that these cats would have been better off if they’d been rounded up and killed “humanely.” A preemptive strike against the inevitability of “short, brutal lives.” (This phrase, which I first saw used by Jessup, [28] has become remarkably popular among TNR opponents.)

But is it that simple? Applying the same logic (if that’s what it is) to pelicans covered in oil, for instance, would we suggest that these birds should either be in captivity or “humanely euthanized”? Obviously not.

Divergent Perspectives on Animal Welfare
While I disagree that “the debate is predominately about whether cats should be allowed to run wild across the landscape and, if not, how to effectively and humanely manage them,” [29] I tend to agree with Lepczyk et al. when they write:

“It’s much more about human views and perceptions than science—a classic case where understanding the human dimensions of an issue is the key to mitigating the problem.” [29]

But, like Dauphine and Cooper, Lepczyk et al. seem more interested in broadcasting their message—loudly, ad nauseam—than in listening. “We need to understand whether people are even aware,” they write, “of the cumulative impact that their actions—choosing to let cats outdoors—can have on wildlife populations.” [29]

Although it’s packaged somewhat “softly,” we’re back to the same old speculative connections between predation and population impacts (familiar terrain for Lepczyk, who tried to connect these same dots in his PhD research). But how much of a connection is there, really? In their review of 61 predation studies, Mike Fitzgerald and Dennis Turner are unambiguous:

“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.” [30]

While the tone used by Lepczyk et al. is very much “we’re all in this together,” their prescription for “moving forward” suggests little common ground. (They actually cite that 2010 letter to Conservation Biology [28]—not much of an olive branch.)

“One approach is exemplified in Hawaii,” explain the authors, “where we’ve become part of a large coalition of stakeholders working together with the shared goal of reducing and eventually removing feral cats from the landscape.” [29] So, who’s involved?

“Our diverse group includes individuals from the Humane Society of the United States, the Hawaiian Humane Society, the U.S. Fish and Wildlife Service, the National Park Service, Hawaii’s Department of Land and Natural Resources, and the University of Hawaii. Our team also regularly interacts with other groups around the nation such as regional Audubon Societies and the American Bird Conservancy. Several stakeholders in the group have differing views, such as on whether or not euthanasia or culling is appropriate, or whether people should feed feral cats.” [29]

Other than the Humane Society organizations (whose position on TNR I don’t take for granted, considering they were early supporters of ABC’s Cats Indoors! campaign [31]), I don’t see a real diversity of views in this coalition.

I suppose it’s easy to make room at the table when you’re offering so few seats.

For Dauphine, though, any such collaboration approaches treason. Or selling out, at least.

“In some cases,” she explains, “conservation groups accept funding to join in efforts promoting TNR. The New Jersey Audubon Society, for example, had previously rejected TNR but began supporting it in 2005, acknowledging funding from the Frankenberg and Dodge Foundations for collaboration with TNR groups.” [24]

Dauphine doesn’t go into detail about the amount of funding, and it’s not clear what, if any, role it played in the decision by NJAS (which took in $6.8 million in 2008) to participate in the New Jersey Feral Cat-Wildlife Coalition—the kind of collaborative effort that should be encouraged, not derided:

“From 2002 to 2005, NJAS had actively opposed the practice of TNR in New Jersey. Despite this opposition, municipalities continued to adopt TNR ordinances. In 2005, NJAS, American Bird Conservancy, Neighborhood Cats and Burlington Feral Cat Initiative began exploratory dialogue about implementing standards to protect rare wildlife vulnerable to cat predation in towns which have already adopted TNR programs.” [32]

Message Received, Loud and Clear
Rather than wringing their hands over how to “better communicate the science” [1] or how to better facilitate “legal or policy changes, incentives, and increased education,” [29] TNR opponents might want to reconsider the message itself.

What they are proposing is the killing—on an unprecedented scale—of this country’s most popular pet.

I don’t imagine this tests well with focus groups and donors, of course, but there it is.

These people seem perplexed by a community’s willingness to adopt TNR (“In the end,” lament Lepczyk et al., referring to the decision in Athens, GA, “the professional opinion of wildlife biologists counted no more than that of any other citizen, a major reason for the defeat.” [29]) but fail to recognize how profoundly unpalatable their alternative is.

And, unworkable, too.

Which may explain why it’s virtually impossible to get them to discuss their “plan” in any detail. (I was unsuccessful, for example, in pinning down Travis Longcore during our back-and-forth on the Audubon magazine’s blog and couldn’t get Jessup or Hutchins to bite when I asked the same question during an online discussion of public health risks.)

In light of what’s involved with “successful” eradication programs, I’m not surprised by their eagerness to change the subject.

  • On Marion Island, it took 19 years to eradicate something like 2,200 cats—using disease (feline distemper), poisoning, intensive hunting and trapping, and dogs. This on an island that’s only 115 square miles in total area, barren, and uninhabited. [33, 34] The cost, I’m sure, was astronomical.
  • On the sparsely populated (fewer than 1,000, according to Wikipedia) Ascension Island (less than 34 total square miles), a 2003 eradication effort cost nearly $950,000 (adjusted to 2009 dollars). [35]
  • A 2000 effort on Tuhua (essentially uninhabited, and just 4.9 square miles) ran $78,591 (again, adjusted to 2009 dollars). [35]
  • Efforts on Macquarie Island (also small—47.3 square miles—and essentially uninhabited) proved particularly costly: $2.7 million in U.S. (2009) dollars. And still counting. The resulting rebound in rabbit and rodent numbers prompted “Federal and State governments in Australia [to commit] AU$24 million for an integrated rabbit, rat and mouse eradication programme.” [36] (To put this into context, Macquarie Island is about one-third the size of the Florida Keys.)

These examples represent, in many ways, low-hanging fruit. By contrast, “the presence of non-target species and the need to safely mitigate for possible harmful effects, along with substantial environmental compliance requirements raised the cost of the eradication.” [37] Eradicating rodents from Anacapa Island, “a small [1.2-square-mile] island just 80 miles from Los Angeles International Airport, cost about $2 million.” [38]

Now—setting aside the horrors involved—how exactly do TNR opponents propose to rid the U.S. of it’s millions of feral cats? [cue the sound track of crickets chirping]

I think the general public is starting to catch on. Even if they fall for the outlandish claims about predation, wildlife impacts, and all the rest—they don’t see anything in the way of a real solution. As Mark Kumpf, former president of the National Animal Control Association, put it in an interview with Animal Sheltering magazine, “the traditional methods that many communities use… are not necessarily the ones that communities are looking for today.” [39]

“Traditional” approaches to feral cat management (i.e., trap-and-kill) are, says Kumpf, akin to “bailing the ocean with a thimble.” [39]

For all their apparent interest—22 pages in the current issue of The Wildlife Professional alone—TWS might as well be handing out thimbles to its members. Although Gillin’s “Leadership Letter” invites “dialogue among all stakeholders,” it offers nothing substantive to advance the discussion:

“If removal and euthanasia of unadoptable feral cats is not acceptable to TNR proponents, then they need to offer the conservation community a logical, science-based proposal that will solve the problem of this invasive species and its effect on wildlife and the environment.” [2]

So much for leadership.

Literature Cited
1. Dauphine, N. and Cooper, R.J., “Pick One: Outdoor Cats or Conservation.” The Wildlife Professional. 2011. 5(1): p. 50–56.

2. Gillin, C., “The Cat Conundrum.” The Wildlife Professional. 2011. 5(1): p. 10, 12.

3. APPA, 2009–2010 APPA National Pet Owners Survey. 2009, American Pet Products Association: Greenwich, CT. http://www.americanpetproducts.org/pubs_survey.asp

4. Lord, L.K., “Attitudes toward and perceptions of free-roaming cats among individuals living in Ohio.” Journal of the American Veterinary Medical Association. 2008. 232(8): p. 1159-1167. http://www.avma.org/avmacollections/feral_cats/javma_232_8_1159.pdf

5. 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. http://avmajournals.avma.org/doi/abs/10.2460/javma.2003.222.1541

6. van Heezik, Y., “A New Zealand Perspective.” The Wildlife Professional. 2011. 5(1): p. 70.

7. Sims, V., et al., “Avian assemblage structure and domestic cat densities in urban environments.” Diversity and Distributions. 2008. 14(2): p. 387–399. http://dx.doi.org/10.1111/j.1472-4642.2007.00444.x

8. Wilson, M. (1997). Cats Roaming Free Take a Toll on Songbirds. Boston Globe, p. 11.

9. Seppa, N. (1993, July 22). Millions of Songbirds, Rabbits Disappearing. Wisconsin State Journal, p. 1A.

10.  Wozniak, M.D. (1993, August 3). Feline felons: Barn cats are just murder on songbirds. The Milwaukee Journal, p. A1.

11. 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. http://dx.doi.org/10.1644/09-MAMM-A-111.1

12. Liberg, O. and Sandell, M., Spatial organisation and reproductive tactics in the domestic cat and other felids, in The Domestic cat: The biology of its behaviour, D.C. Turner and P.P.G. Bateson, Editors. 1988, Cambridge University Press: Cambridge; New York. p. 83–98.

13. Castillo, D. and Clarke, A.L., “Trap/Neuter/Release Methods Ineffective in Controlling Domestic Cat “Colonies” on Public Lands.” Natural Areas Journal. 2003. 23: p. 247–253.

14. Nutter, F.B., Evaluation of a Trap-Neuter-Return Management Program for Feral Cat Colonies: Population Dynamics, Home Ranges, and Potentially Zoonotic Diseases, in Comparative Biomedical Department. 2005, North Carolina State University: Raleigh, NC. p. 224.

15. Stoskopf, M.K. and Nutter, F.B., “Analyzing approaches to feral cat management—one size does not fit all.”Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1361–1364. http://www.ncbi.nlm.nih.gov/pubmed/15552309

www.avma.org/avmacollections/feral_cats/javma_225_9_1361.pdf

16.  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. http://www.sciencedirect.com/science/article/B6TBK-4M33VSW-1/2/0abfc80f245ab50e602f93060f88e6f9

www.kiccc.org.au/pics/FeralCatsRome2006.pdf

17. Levy, J.K. and Crawford, P.C., “Humane strategies for controlling feral cat populations.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1354–1360. http://www.avma.org/avmacollections/feral_cats/default.asp

http://www.avma.org/avmacollections/feral_cats/javma_225_9_1354.pdf

18. 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

19. 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://www.avma.org/avmacollections/feral_cats/javma_229_1_74.pdf

20. 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

21. Jessup, D.A. and Miller, M.A., “The Trickle-Down Effect.” The Wildlife Professional. 2011. 5(1): p. 62–64.

22. 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

23. 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

24. Dauphine, N., “Follow the Money: The Economics of TNR Advocacy.” The Wildlife Professional. 2011. 5(1): p. 54.

25. Hatley, P.J., “Incompatible Neighbors in the Florida Keys.” The Wildlife Professional. 2011. 5(1): p. 52–53.

26. O’Hara, T. (2007, April 3). Fish & Wildlife Service to begin removing cats from Keys refuges. The Key West Citizen, from http://keysnews.com/archives

27. n.a., Lower Florida Keys National Wildlife Refuges Comprehensive Conservation Plan. 2009, U.S. Department of the Interior, Fish and Wildlife Service: Atlanta, GA. http://www.fws.gov/nationalkeydeer/

http://www.fws.gov/southeast/planning/PDFdocuments/Florida%20Keys%20FINAL/TheKeysFinalCCPFormatted.pdf

28. Jessup, D.A., “The welfare of feral cats and wildlife.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1377-1383. http://www.ncbi.nlm.nih.gov/pubmed/15552312

http://www.avma.org/avmacollections/feral_cats/javma_225_9_1377.pdf

29. Lepczyk, C.A., van Heezik, Y., and Cooper, R.J., “An Issue with All-Too-Human Dimensions.” The Wildlife Professional. 2011. 5(1): p. 68–70.

30. 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.

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

32. Stiles, E., NJAS Works with Coalition to Reduce Bird Mortality from Outdoor Cats. 2008, New Jersey Audubon Society. http://www.njaudubon.org/Portals/10/Conservation/PDF/ConsReportSpring08.pdf

33. Bester, M.N., et al., “A review of the successful eradication of feral cats from sub-Antarctic Marion Island, Southern Indian Ocean.” South African Journal of Wildlife Research. 2002. 32(1): p. 65–73.

http://www.ceru.up.ac.za/downloads/A_review_successful_eradication_feralcats.pdf

34. Bloomer, J.P. and Bester, M.N., “Control of feral cats on sub-Antarctic Marion Island, Indian Ocean.” Biological Conservation. 1992. 60(3): p. 211-219. http://www.sciencedirect.com/science/article/B6V5X-48XKBM6-T0/2/06492dd3a022e4a4f9e437a943dd1d8b

35. Martins, T.L.F., et al., “Costing eradications of alien mammals from islands.” Animal Conservation. 2006. 9(4): p. 439–444. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-1795.2006.00058.x/abstract

http://i3n.iabin.net/documents/pdf/Costingeradicationsofalienmammalsfromislands.pdf

36. Bergstrom, D.M., et al., “Indirect effects of invasive species removal devastate World Heritage Island.” Journal of Applied Ecology. 2009. 46(1): p. 73-81. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2008.01601.x/abstract

http://eprints.utas.edu.au/8384/4/JAppEcol_Bergstrom_etal_journal.pdf

37. Donlan, C.J. and Heneman, B., Maximizing Return on Investments for Island Restoration with a Focus on Seabird Conservation. 2007, Advanced Conservation Strategies: Santa Cruz, CA. http://www.advancedconservation.org/roi/ACS_Seabird_ROI_Report.pdf

38. Donlan, C.J. and Wilcox, C., Complexities of costing eradications, in Animal Conservation. 2007, Wiley-Blackwell. p. 154–156. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-1795.2007.00101.x/abstract

http://www.advancedconservation.org/library/donlan_&_wilcox_2007a.pdf

39. Hettinger, J., Taking a Broader View of Cats in the Community, in Animal Sheltering. 2008. p. 8–9. http://www.animalsheltering.org/resource_library/magazine_articles/sep_oct_2008/taking_a_broader_view_of_cats.html

http://www.animalsheltering.org/resource_library/magazine_articles/sep_oct_2008/broader_view_of_cats.pdf

Best Available Science?

After a while, I suppose, such things will no longer surprise me.

A couple weeks ago, the American Bird Conservancy released a statement in support of the Florida Keys National Wildlife Refuges Complex Integrated Predator Management Plan/Draft Environmental Assessment proposed by the U.S. Fish and Wildlife Service (USFWS):

“American Bird Conservancy, the nation’s leading bird conservation organization, and 27 additional science and conservation organizations have signed a letter to the Florida Keys National Wildlife Refuge supporting their plans to remove cats and cat feeding stations found on refuge lands in the Keys because of the harm they are causing to birds and other wildlife, including endangered species.”

No surprise there, really. It’s the following paragraph that caught my eye:

“The U.S. Fish and Wildlife Service deserves credit for bringing the best available science to bear on the management of exotic predators inhabiting National Wildlife Refuge lands regardless of the emotional aspects of the issue,” said Steve Holmer, Senior Policy Advisor for American Bird Conservancy. “Given the overwhelming evidence of harm to native birds inhabiting and migrating through the Keys, this predator management plan offers hope for healthier environment.”

“Best available science”? Are we talking about the same document here?

Granted, this is Steve Holmer—the same guy who, a year ago, told the Los Angeles Times that there are 160 million feral cats in the U.S. (a figure he arrived at by “reinterpreting” the already inflated figure proposed by Dauphine and Cooper).

In other words, consider the source.

Among the letter’s highlights (the letter itself doesn’t seem to be available, which is a shame, as I’m very interested in knowing which other “science and conservation organizations” are supporters):

“…cat predation accounted for 50 percent and 77 percent of mortality of two endangered species—the Lower Keys Marsh Rabbit and the Key Largo Woodrat.”

Lower Keys Marsh Rabbit
ABC’s claim about cats being responsible for half the mortality of marsh rabbits doesn’t actually correspond with what’s in the USFWS plan:

“Free-roaming domestic cat predation accounted for 50 percent of adult Lower Keys marsh rabbit mortality during radio telemetry studies and was cited as the largest factor limiting their population viability in the 1990s (Forys and Humphrey 1999).” [1]

During her PhD dissertation work, Elizabeth Forys’ found that 13 of 24 rabbits monitored over the course of her research were killed by cats, [2] findings she described four years later (in the paper cited by USFWS) this way:

“Twenty-seven (18 M, 9 F) of the 43 radiocollared individuals died during our 2.5-year study. Domestic cats killed the most marsh rabbits (53 percent of all mortality), killing nearly an equal number of both juvenile and adult marsh rabbits.” [3]

ABC misrepresents both Forys’ work and the USFWS plan by transforming those 13 marsh rabbits into “50 percent of mortality of [this] endangered species.” And this is too straightforward to be an accident.

For what it’s worth, this has been done before.

Impact of Cats on Marsh Rabbits
The Multi-Species Recovery Plan (MSRP) for South Florida, published in 1999 by USFWS, refers repeatedly to Forys’ work, noting, for example:

“Although habitat loss is responsible for the original decline of the Lower Keys marsh rabbit, high mortality from cats may be the greatest current threat to the persistence of the Lower Keys marsh rabbit [4].”

The report’s authors alternate between concessions and allegations, the latter of which are based on what can only be considered—even in the most generous light—circumstantial evidence. They acknowledge, for instance, that “a detailed study of cat diets in the Keys has not been conducted,” but then point out that “rabbits were the largest component of feral cat diets in several studies that have been conducted elsewhere (Jones and Coman 1981, Liberg 1985).” [5]

Let’s set aside for the moment the debate about whether or not two is considered “several” (and the fact that they got the year wrong on the Liberg study). Where exactly were those studies conducted? “Victorian Mallee, Kinchega National Park in western New South Wales, and the Victorian eastern highlands” [6] and “Revinge area in southern Sweden.” [7]

None of which, it’s safe to say, could be mistaken for the Florida Keys.

USFWS also acknowledges that “the exact extent [of predation by cats] cannot be determined,” though they imply that it must be increasing: “the number of cats present in the Lower Keys has increased over the past 20 years with the increase in the residential population.” [5]

(In fact, a number of studies have shown that cats will shift their “preferences” according to prey availability [see, for example, the review in 8]. Indeed, this was the case in the study from southern Sweden cited by USFWS: “Wild rabbits were the most important prey, and cats responded functionally to changes in abundance and availability of this prey.” [7])

The less common the rabbits, the less likely they are to fall prey to free-roaming cats.

Telling Stories
Somewhere along the line, though, the marsh rabbit story began to change.

An article in The Key West Citizen describing USFWS’s 2007 effort to round up cats in the Keys [9, 10] is a clear reference to—and equally clear misrepresentation of—Forys’ work:

“According to a 1999 U.S. Fish and Wildlife report, feral cats have killed 53 percent of marsh rabbits in the Lower Keys.” [9]

Contributors to the 2008 South Florida Environmental Report claim, “feral cats… have contributed to a 50 percent decline in populations of Hugh Hefner’s rabbits (Sylvilagus palustris hefneri, an endangered subspecies of marsh rabbit named for Hefner’s contributions to their research) on Big Pine Key (CNN.com, accessed May 20, 2007).” [11] I was unable to find anything at the CNN site, but suspect the story was nothing more than a pick-up of the story that ran in The Key West Citizen. (Florida residents will no doubt take great comfort in knowing that the South Florida Water Management District, publisher of the report, is unwilling to look any further than CNN.com for its science.)

In the 2009 book Invasive Species: Detection, Impact and Control, the story is much the same:

“[cats] have been a factor in the 50 percent decline in populations of the endangered Lower Keys marsh rabbit (Forys and Humphrey 1999).” [12]

In fact, Forys and Humphrey have little to say about the declining population:

“During the 1970s and 1980s, a period of intense habitat destruction, a decline in marsh rabbits was reported (Lazell 1984).” [3]

And Lazell? Nothing at all about the marsh rabbit population. I did, however, find this interesting:

“In 1980 I live-trapped five specimens on Lower Sugarloaf Key under Florida Game and Fresh Water Fish Commission (FGFWFC) permit 28. Three were prepared as skins and skeletons; two were released after physiological studies (Dunson and Lazell, 1982).” [13]

Not that Lazell was the only scientist taking marsh rabbits. North of the Keys, 10 years earlier, Nicholas Holler and Clinton Conaway were studying the reproduction of this now-endangered species.

“From September 1968 through August 1969, 610 marsh rabbits were collected by hand or with a .22 caliber rifle in sugarcane plantations south and west of Belle Glade, Palm Beach and Hendry counties, Florida, at the southern edge of Lake Okeechobee. Rabbits were readily obtained except in July, August, and September…. After collection, rabbits were weighed and one eye and one front paw were preserved in 10 percent formalin.” [14]

To put this into perspective, the MSRP (published 30 years after Holler and Conway’s research) suggests that there may be only 100–300 marsh rabbits left. [5]

How’s that for irony? It seems the best evidence of a declining population comes from two scientists who killed several hundred marsh rabbits 40 years ago.

Key Largo Woodrat
ABC’s reference to Key Largo woodrat mortality is actually an accurate recounting of what’s in the USFWS plan:

“In addition, cats accounted for 77 percent of the mortality during a recent re-introduction of the Key Largo woodrat (S. Klett, Refuge Manager, personal communication).” [1]

Such personal communications—even by knowledgeable, honest professionals—are no substitute for rigorous, science-based reporting. What kind of sample size are we talking about? Over what duration? Under what conditions? Where? Etc.

More to the point, though: here is ABC once again blatantly misrepresenting the science (or the closest thing we’ve got to science, in this case). USFWS is talking about a portion of the population, while ABC is talking about the entire population. And I have to think the people responsible are smart enough to know the difference—which, of course, can mean only one thing: it’s not the intelligence that’s lacking here, but the integrity.

The Rest of the Best
But what about all the rest of the science—the “best available,” according to Holmer, don’t forget—that USFWS including in its Integrated Predator Management Plan/Draft Environmental Assessment? Among the more egregious errors and misinterpretations I cited in my comments to USFWS:

  • Another of the papers cited by USFWS has nothing to do with extinctions at all. As the authors describe it, their study was an evaluation of “whether a collar-worn pounce protector, the CatBib, reduces the number of vertebrates caught by pet cats and whether its effectiveness was influenced by colour or adding a bell.” [17]
  • Listed among the “evidence” of island extinctions were studies that—in addition to having nothing to do with extinctions—were not conducted on islands. Coleman and Temple’s 1993 survey, for example, involved rural Wisconsin residents and their outdoor cats, [18] while Churcher and Lawton surveyed residents of a small English village. [19]
  • Among the evidence that “free-roaming cats kill at least one billion birds every year in the U.S., representing one of the largest single sources of human-influenced mortality for small native wildlife,” [1] is Rich Stallcup’s 1991 article from the Observer, a publication of the Point Reyes Bird Observatory. In fact, “A Reversible Catastrophe” is little more than Stallcup’s advice—at once both folksy and sinister—about defending one’s garden from neighborhood cats (“…try a B-B or pellet gun. There is no need to kill or shoot toward the head, but a good sting on the rump seems memorable for most felines, and they seldom return for a third experience.” [21]).
  • Another of the studies cited by FWS—a 2008 paper by Sax and Gaines—isn’t about cats at all. Or even invasive animals. It’s about invasive plants. [22]
  • Citing the Centers for Disease Control and Prevention’s website, USFWS argues: “…free-roaming cats not only threaten wildlife through direct predation but also serve as vectors for a number of diseases including rabies, cat scratch fever, hookworms, roundworms and toxoplasmosis. Some of these diseases can be transmitted to other domestic animals, native wildlife, and in some cases, humans.”

    In fact, the CDC site makes no mention of cats being a threat to wildlife. And humans? “Although cats can carry diseases and pass them to people, you are not likely to get sick from touching or owning a cat.” And, notes the CDC, “People are probably more likely to get toxoplasmosis from gardening or eating raw meat than from having a pet cat.”

    (Unwilling to do their own research and writing, ABC uses exactly the same language and cites the same CDC website as USFWS. Had they simply clicked on the link, they might have avoided the blunder—which, I think, speaks volumes about little scrutiny they gave the USFWS plan before backing it.)

This is what Holmer is referring to when he says USFWS “deserves credit for bringing the best available science to bear on the management of exotic predators inhabiting National Wildlife Refuge lands regardless of the emotional aspects of the issue.”

What’s Missing
In addition to everything USFWS gets wrong, though, there’s also everything they overlooked or ignored (again, each point is covered in detail in my comments to USFWS). For example:

Mesopredator Release
“In the absence of large, dominant predators,” write Soulé et al., “smaller omnivores and predators undergo population explosions, sometimes becoming four to 10 times more abundant than normal.” [23] Several studies have demonstrated such an “explosion” of non-native rat populations as a result of cat populations being eliminated. [24–27]

As Courchamp et al. explain, “although counter-intuitive, eradication of introduced superpredators, such as feral domestic cats, is not always the best solution to protect endemic prey when introduced mesopredators, such as rats, are also present.” [26] Fan et al. warn of the risks involved with such eradication efforts: “In some cases, it may cause a disastrous impact to managed or natural ecosystems.” [25]

But USFWS doesn’t even mention the risk of mesopredator release, despite the fact that—should the population of free-roaming cats be sufficiently reduced—the situation in the Keys suggests that such an outcome is actually quite likely. And controlling these rats is complicated considerably by the need to protect Lower Keys marsh rabbits. Indeed, the MSRP warns of these rabbits coming into contact with pesticides and “poisons used to control black rats.” [5]

Based on evidence cited by USFWS itself, it’s clear that a dramatic reduction in the number of free-roaming cats in the Keys (assuming it’s possible—see below) will very likely have a negative impact on the marsh rabbit population—and may well lead to their extirpation from any Key where these rats are present.

Such impacts would also likely affect the Key Largo cotton mouse [28–29], Key Largo woodrat [30–31], and silver rice rat [32–33], all of which USFWS identifies as species of particular concern, and which are threatened—either through predation or competition—by non-native rats such as the black rat.

Removing Cats
Reports indicate that USFWS has a rather poor track record when it comes to trapping cats. Its 2003 contract with USDA, for example, yielded just 23 cats over 31 days of trapping. [34] Their efforts four years later—at a cost of $50,000—were equally ineffective. [9–10]

None of which should surprise USFWS. “Successful” eradication efforts require both extraordinary resources and profound cruelty. For example:

  • Nogales et al., describing the “success” of Marion Island, note, “it took about 15 years of intense effort to eradicate the cats, combining several methods such as trapping, hunting, poisoning, and disease introduction… The use of disease agents or targeted poisoning campaigns hold promise for an initial population reduction in eradication programs on large islands—such an approach may save effort, time, and money.” [35]
  • Cruz and Cruz point out that, of all the non-native mammals there, cats were “the most difficult to control or eliminate on Floreana Island.” Although “hunting with dogs was the single most effective method employed and it gave a sure body count,” the authors warn that “the method was costly and with the limited manpower available was only useful over small areas. Both poisoning and trapping were effective and the combination of the three methods is probably the most effective approach, as well as being the best use of time and materials.” [15]
  • Veitch describes efforts on 11-square-mile Little Barrier Island as “a determined [cat] eradication attempt” involving “cage traps, leg-hold traps, dogs and 1080 poison were used, but leg-hold traps and 1080 poison were the only effective methods.” [36] Four cats were also infected with Feline enteritis, but “because of the poor reaction to the virus no other cats were dosed and none were released… Altogether, 151 cats were known to have been killed before the eradication was declared complete. Important lessons learnt can be transferred to other feral cat eradication programmes.” [36] (By way of comparison, the Keys are approximately 137 square miles in total area.)

As USFWS admits, such methods are “not… socially acceptable” and “inconsistent with the points of consensus developed by the stakeholder group.” Yet, they offer nothing in the way of a feasible alternative; their latest plan is just more of what’s been done—and proven ineffective—in the past.

Because it’s extremely doubtful that USFWS will be able to remove the cats quickly enough to keep up with reproduction rates (again, consider the “success” stories outlined above), the most likely outcome of their plan is an increase in the number of feral cats in the Keys—and, of course, a corresponding increase in the negative impacts they have on the area’s wildlife and environment.

•     •     •

I fully expected ABC to support the USFWS plan. And, come to think of it, I should have expected them to blindly embrace the underlying science. After all, this is the same organization that’s been trying, since at least 1997, to sell the Wisconsin Study as valid research.

And, more recently, ABC endorsed “Feral Cats and Their Management” (also known as the University of Nebraska report) as if it were valid research.

Perhaps this is what ABC President and CEO George Fenwick meant when he wrote, in the preface to The American Bird Conservancy Guide to Bird Conservation, “every point of view has its own science.” [37]

Literature Cited
1. n.a., Draft Environmental Assessment: Florida Keys National Wildlife Refuges Complex Integrated Predator Management Plan. 2011, U.S. Fish & Wildlife Service: Big Pine Key, FL. http://www.fws.gov/nationalkeydeer/predatormgmt.html

http://www.fws.gov/nationalkeydeer/pdfs/USFWS%20FL%20Keys%20Refuges%20Integrated%20Predator%20Mgmt%20Plan%20&%20EA%20FINAL%20DRAFT.pdf

2. Forys, E.A., Metapopulations of marsh rabbits: A population viability analysis of the Lower Keys marsh rabbit (Sylvilagus palustris hefneri), in Department of Wildlife Ecology and Conservation. 1995, University of Florida: Gainesville. p. 244.

3. Forys, E.A. and Humphrey, S.R., “Use of Population Viability Analysis to Evaluate Management Options for the Endangered Lower Keys Marsh Rabbit.” The Journal of Wildlife Management. 1999. 63(1): p. 251–260. http://www.jstor.org/stable/3802507

4. Forys, E.A. and Humphrey, S.R., “Home Range and Movements of the Lower Keys Marsh Rabbit in a Highly Fragmented Habitat.” Journal of Mammalogy. 1996. 77(4): p. 1042-1048. http://www.jstor.org/stable/1382784

5. n.a., Multi-Species Recovery Plan for South Florida: Lower Keys Rabbit. 1999, U.S. Fish and Wildlife Service: Atlanta, GA. p. 151–171. http://www.fws.gov/verobeach/index.cfm?Method=programs&NavProgramCategoryID=3&programID=107&ProgramCategoryID=3

www.fws.gov/verobeach/images/pdflibrary/lkmr.pdf

6. Jones, E. and Coman, B.J., ” Ecology of the feral cat, Felis catus (L.), in southeastern Australia.” Australian Wildlife Research. 1981. 8: p. 537–547. http://www.publish.csiro.au/paper/WR9810537.htm

7. Liberg, O., “Food Habits and Prey Impact by Feral and House-Based Domestic Cats in a Rural Area in Southern Sweden.” Journal of Mammalogy. 1984. 65(3): p. 424-432. http://www.jstor.org/stable/1381089

8. Fitzgerald, B.M., Diet 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. 1988, Cambridge University Press: Cambridge; New York. p. 123–147.

9. O’Hara, T. (2007, April 3). Fish & Wildlife Service to begin removing cats from Keys refuges. The Key West Citizen, from http://keysnews.com/archives

10. n.a., Lower Florida Keys National Wildlife Refuges Comprehensive Conservation Plan. 2009, U.S. Department of the Interior, Fish and Wildlife Service: Atlanta, GA. http://www.fws.gov/nationalkeydeer/

http://www.fws.gov/southeast/planning/PDFdocuments/Florida%20Keys%20FINAL/TheKeysFinalCCPFormatted.pdf

11. Ferriter, A., et al., The Status of Nonindigenous Species in the South Florida Environment, in 2008 South Florida Environmental Report. 2008, South Florida Water Management District.

12.  Engeman, R., Constantin, B., and Hardin, S., “Species Pollution” in Florida: A Cross Section of Invasive Vertebrate Issues and Management Responses, in Invasive Species: Detection, Impact and Control, C.P. Wilcox and R.B. Turpin, Editors. 2009. p. 179–197.

13. Lazell, J.D., Jr., “A New Marsh Rabbit (Sylvilagus palustris) from Florida’s Lower Keys.”Journal of Mammalogy. 1984. 65(1): p. 26–33. http://www.jstor.org/stable/1381196

14. Holler, N.R. and Clinton, H.C., “Reproduction of the Marsh Rabbit (Sylvilagus palustris) in South Florida.” Journal of Mammalogy. 1979. 60(4): p. 769–777. http://www.jstor.org/stable/1380192

15. Cruz, J.B. and Cruz, F., “Conservation of the dark-rumped petrel Pterodroma phaeopygia in the Galápagos Islands, Ecuador.” Biological Conservation. 1987. 42(4): p. 303-311. http://www.sciencedirect.com/science/article/B6V5X-48XKMBP-17J/2/f81b57e317f217802d9aca8b6927a88c

16. Kirkpatrick, R.D. and Rauzon, M.J., “Foods of Feral Cats Felis catus on Jarvis and Howland Islands, Central Pacific Ocean.” Biotropica. 1986. 18(1): p. 72-75. http://www.jstor.org/stable/2388365

17. Calver, M., et al., “Reducing the rate of predation on wildlife by pet cats: The efficacy and practicability of collar-mounted pounce protectors.” Biological Conservation. 2007. 137(3): p. 341-348. http://www.sciencedirect.com/science/article/B6V5X-4NGBB7H-3/2/456180347a2c3916d1ae99e220dd329e

18. Coleman, J.S. and Temple, S.A., “Rural Residents’ Free-Ranging Domestic Cats: A Survey.”Wildlife Society Bulletin. 1993. 21(4): p. 381–390. http://www.jstor.org/pss/3783408

19. Churcher, P.B. and Lawton, J.H., “Predation by domestic cats in an English village.” Journal of Zoology. 1987. 212(3): p. 439-455. http://dx.doi.org/10.1111/j.1469-7998.1987.tb02915.x

20. 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.

21. Stallcup, R., “A reversible catastrophe.” Observer 91. 1991(Spring/Summer): p. 8–9. http://www.prbo.org/cms/print.php?mid=530

http://www.prbo.org/cms/docs/observer/focus/focus29cats1991.pdf

22. Sax, D.F. and Gaines, S.D., Species invasions and extinction: The future of native biodiversity on islands, in In the Light of Evolution II: Biodiversity and Extinction,. 2008: Irvine, CA. p. 11490–11497. www.pnas.org/content/105/suppl.1/11490.full

http://www.pnas.org/content/105/suppl.1/11490.full.pdf

23. Soulé, M.E., et al., “Reconstructed Dynamics of Rapid Extinctions of Chaparral-Requiring Birds in Urban Habitat Islands.” Conservation Biology. 1988. 2(1): p. 75–92. http://www.jstor.org/pss/2386274

http://deepblue.lib.umich.edu/bitstream/2027.42/74761/1/j.1523-1739.1988.tb00337.x.pdf

24. Fitzgerald, B.M., Karl, B.J., and Veitch, C.R., “The diet of feral cat (Felis catus) on Raoul Island, Kermadec group.” New Zealand Journal of Ecology. 1991. 15(2): p. 123–129. http://www.feral.org.au/the-diet-of-feral-cats-felis-catus-on-raoul-island-kermadec-group/

www.newzealandecology.org.nz/nzje/free_issues/NZJEcol15_2_123.pdf

25. Fan, M., Kuang, Y., and Feng, Z., “Cats protecting birds revisited.” Bulletin of Mathematical Biology. 2005. 67(5): p. 1081–1106. http://www.springerlink.com/content/p0h5854n56183874/

26. Courchamp, F., Langlais, M., and Sugihara, G., “Cats protecting birds: modelling the mesopredator release effect.” Journal of Animal Ecology. 1999. 68(2): p. 282–292. http://dx.doi.org/10.1046/j.1365-2656.1999.00285.x

http://deepeco.ucsd.edu/~george/publications/99_cats_protecting.pdf

27. Bergstrom, D.M., et al., “Indirect effects of invasive species removal devastate World Heritage Island.” Journal of Applied Ecology. 2009. 46(1): p. 73-81. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2008.01601.x/abstract

http://eprints.utas.edu.au/8384/4/JAppEcol_Bergstrom_etal_journal.pdf

28. n.a., Key Largo Cotton Mouse (Peromyscus gossypinus allapaticola) 5-Year Review: Summary and Evaluation. 2009, U.S. Fish and Wildlife Service, Southeast Region, South Fiorida Ecological Services Office: Veero Beach, FL. p. 19. http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A086

http://ecos.fws.gov/docs/five_year_review/doc2378.pdf

29. n.a., Multi-Species Recovery Plan for South Florida: Key Largo Cotton Mouse. 1999, U.S. Fish and Wildlife Service: Atlanta, GA. p. 79–96. http://www.fws.gov/verobeach/index.cfm?Method=programs&NavProgramCategoryID=3&programID=107&ProgramCategoryID=3

http://www.fws.gov/verobeach/images/pdflibrary/klcm.pdf

30. n.a., Key Largo Woodrat (Neotomafloridana smalli) 5-Year Review: Summary and Evaluation. 2008, U.S. Fish and Wildlife Service, Southeast Region, South Fiorida Ecological Services Office: Vero Beach, FL. http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A087

http://ecos.fws.gov/docs/five_year_review/doc1985.pdf

31. n.a., Multi-Species Recovery Plan for South Florida: Key Largo Woodrat. 1999, U.S. Fish and Wildlife Service: Atlanta, GA. p. 195–216. http://www.fws.gov/verobeach/index.cfm?Method=programs&NavProgramCategoryID=3&programID=107&ProgramCategoryID=3

http://www.fws.gov/verobeach/images/pdflibrary/klwr.pdf

32. n.a., Multi-Species Recovery Plan for South Florida: Rice Rat. 1999, U.S. Fish and Wildlife Service: Atlanta, GA. p. 173–194. http://www.fws.gov/verobeach/index.cfm?Method=programs&NavProgramCategoryID=3&programID=107&ProgramCategoryID=3

http://www.fws.gov/verobeach/images/pdflibrary/srra.pdf

33. n.a., Rice rat (Oryzomys palustris natator) 5-Year Review: Summary and Evaluation. 2008, U.S. Fish and Wildlife Service, Southeast Region, South Florida Ecological Services Office: Vero Beach, FL. http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A083

http://ecos.fws.gov/docs/five_year_review/doc1958.pdf

34. n.a., Feral and Free-Ranging Cat Trapping by the USDA, APHIS, Wildlife Services (WS) on North Key Largo. 2004, U.S. Department of Agriculture.

35. Nogales, M., et al., “A Review of Feral Cat Eradication on Islands.” Conservation Biology. 2004. 18(2): p. 310–319. http://onlinelibrary.wiley.com/doi/10.1111/j.1523-1739.2004.00442.x/abstract

36. Veitch, C.R., “The eradication of feral cats (Felis catus) from Little Barrier Island, New Zealand.” New Zealand Journal of Zoology. 2001. 28: p. 1–12. http://www.royalsociety.org.nz/publications/journals/nzjz/2001/001/

http://www.royalsociety.org.nz/media/publications-journals-nzjz-2001-001.pdf

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

Reviving a Classic

“The cat, of all animals, is in some respects the most intimate companion of man… Nevertheless, it leads a dual existence. ‘The fireside sphinx,’ the pet of the children, the admired habitué of the drawing-room or the salon by day, may become at night a wild animal, pursuing, striking down and torturing its prey, frequently making night hideous with its cries, sneaking into dark, filthy, noisome retreats, or taking to the woods and fields, where it perpetrates untold mischief. Now it ravages the dovecote; now it steals on the mother bird asleep on her nest, striking bird, nest and young to the ground. In the darkness of night it turns poacher. No animal that it can reach and master is safe from its ravenous clutches.” —Edward Howe Forbush, The Domestic Cat: Bird Killer, Mouser and Destroyer of Wild Life; Means of Utilizing and Controlling It (1916)

Among the numerous criticisms of “Feral Cats and Their Management,” we can now add lack of originality.

In the January/February issue of Animal People, editor Merritt Clifton confirms his “hunch that ‘Feral Cats and Their Management’ is little more than a paraphrased and condensed update of the 1916 tract The Domestic Cat: Bird Killer, Mouser and Destroyer of Wild Life; Means of Utilizing and Controlling It, authored by then-Massachusetts state ornithologist Edward Howe Forbush.”

After a careful re-reading of the 1916 work (available online), Clifton (whose comprehensive article, “Where Cats Belong—and Where They Don’t,” I have quoted repeatedly) concludes:

“…the University of Nebraska paper and the Forbush work follow almost identical outlines from beginning to end, making similar allegations, arriving at the same recommendations in closely parallel language.” [1]

The Domestic Cat: Bird Killer, Mouser and Destroyer of Wild Life; Means of Utilizing and Controlling It

“The major structural difference,” writes Clifton, has to do with the sources involved. Whereas Forbush relied largely on “anecdotal testimony from more than 200 individual correspondents” (much of it from hunters who were after the same birds the cats were pursuing), Hildreth, Vantassel, and Hygnstrom provide “no firsthand testimony.” [1]

Instead, notes Clifton, they “plugged in references to more recent studies… in support of essentially the same claims, including that cats devastate populations of birds who would otherwise be hunted.” [1]

Among the similarities described in Clifton’s article:

Fecundity
Like Forbush, the authors of “Feral Cats and Their Management” use “outlandishly high claims about feline fecundity” [1] to drum up support for their eradication (“Hence the necessity for checking such increase promptly by killing all superfluous kittens soon after birth,” [2, p. 19] as Forbush put it).

For their reprise of Bird Killer, Mouser and Destroyer of Wild Life, Hildreth, Vantassel, and Hygnstrom turn to a frequently cited—but bogus—figure:

“The Humane Society of the United States estimates that a pair of breeding cats and their offspring can produce over 400,000 cats in seven years under ideal conditions, assuming none die.” [3]

But of course, feral cats—like all animals, and especially those living outdoors—don’t live “under ideal conditions.” And kittens do die. (The fact that Hildreth, Vantassel, and Hygnstrom leave it that is telling: their intent has nothing whatsoever to do with science, or research of any kind.)

In fact, the Wall Street Journal’s “Numbers Guy,” Carl Bialik, discredited this myth four years earlier in his column. What’s more, John Snyder, Vice President, Companion Animals, told Bialik then that HSUS wasn’t the source, adding, “that number is flawed.” (I’ve searched the HSUS website and can find no mention of it.)

Predation and Impact
Clifton points out that Forbush ignored reliable information indicating that free-roaming cats kill, on average 10 or 11 birds annually, and instead “dwelt on the claims of 15 people that their cats killed 20.4 birds per month, and the claims of six people that their cats killed about 50 birds per year.”

It’s not clear what information Hildreth, Vantassel, and Hygnstrom relied on, as they didn’t bother with in-text citations. Whatever the source, the authors settled on a surprisingly conservative annual predation rate of eight birds per year, and used 60 million as the estimated number of feral cats in the U.S. This, too, might be considered conservative in light of other “estimates,” (the American Bird Conservancy, for example, claims—without citing any source—that the population is 120 million) though Clifton himself estimated, in 2003, 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]

Rather than relying on inflated predation rates to justify the eradication of feral cats, Hildreth, Vantassel, and Hygnstrom misrepresent well-known scientific studies of their impact on wildlife. Their “interpretation” of Olof Liberg’s 1984 paper, for example, and convenient omission of sample size (26 rodents, 21 birds, and 11 lizards) in their reference to Crooks and Soulé’s 1999 paper. [5]

And, not surprisingly, “Feral Cats and Their Management” makes no mention of compensatory predation.

Public Health Threats
“As a carrier of disease,” argued Forbush, “especially to children, no animal has greater opportunities [than the domestic cat].”

Among the threats suggested by Hildreth, Vantassel, and Hygnstrom are cat scratch fever, plague, rabies, ringworm, salmonellosis, fleas, and ticks. And toxoplasmosis—of particular concern, apparently, because “in 3 separate studies, most feral cats (62 percent to 80 percent) tested positive for toxoplasmosis.” [3]

But the rate of cats testing positive—or seroprevalence—is not a useful measure of their ability to infect other animals or people. Indeed, according to the Centers for Disease Control and Prevention:

“Although cats can carry diseases and pass them to people, you are not likely to get sick from touching or owning a cat… People are probably more likely to get toxoplasmosis from gardening or eating raw meat than from having a pet cat.”

•     •     •

“Much of Forbush’s antipathy toward cats,” suggests Clifton, “might be ascribed to the context of the times.”

“His life coincided with the era in which New England wildlife was more depleted than at any time since. Logging, ploughing, damming, and unrestrained development depleted the forest cover, the grasslands, and the rivers. Precocious as Forbush was in his birding, which then was done chiefly with a shotgun, predatory mammals, fur-bearers, and most wild species considered edible had already been extirpated from most of Massachusetts before he had much chance to see or kill them.” [1]

That was 1916. How to explain “Feral Cats and Their Management,” written 94 years later—in, presumably, a very different context? The answer—part of it, anyhow—may lie with one of the paper’s co-authors, Stephen Vantassel, whose PhD dissertation was dedicated to:

“…fur trappers who, every winter, brave the harsh weather in continuance of America’s oldest industry. Regrettably, they must also endure the ravages of urban sprawl and the derision of an ungrateful and ignorant public.” [6]

Vantassel, it seems, would be more at home in the early twentieth century than in the twenty-first. (Though, by 1916, the American Society for the Prevention of Cruelty to Animals was already 50 years old, and the burgeoning animal welfare/right movement would surely have Vantassel longing for “the good old days.”)

Literature Cited
1. Clifton, M. (2011, January/February). The Domestic Cat: Bird Killer, Mouser and Destroyer of Wild Life; Means of Utilizing and Controlling It, by Edward Howe Forbush. Animal People, p. 17, from http://www.animalpeoplenews.org/11/1/Jan-Feb2011.zip%20Folder/Ho8j3PWe.html

http://www.animalpeoplenews.org/11/1/Jan-Feb2011.pdf

2. Forbush, E.H., The Domestic Cat: Bird Killer, Mouser and Destroyer of Wild Life; Means of Utilizing and Controlling It 1916, Boston: Wright and Potter Printing Company.

3. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. http://elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

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

5. Crooks, K.R. and Soulé, M.E., “Mesopredator release and avifaunal extinctions in a fragmented system.” Nature. 1999. 400(6744): p. 563–566. http://www.nature.com/nature/journal/v400/n6744/abs/400563a0.html

6. Vantassel, S.M., Dominion over Wildlife?: An Environmental Theology of Human-Wildlife Relations. 2009: Resource Publications.

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

American Bird Con

For years now, the American Bird Conservancy (ABC) has been promoting erroneous and misleading information in their tireless effort to vilify free-roaming cats. No organization has been more effective at working the anti-TNR pseudoscience into a message neatly packaged for the mainstream media, and eventual consumption by the general public. Speaking to the Wall Street Journal in 2002, Becky Robinson, co-founder and President of Alley Cat Allies, described ABC’s Cats Indoors! campaign as “a new environmental witch hunt.” [1]

Book Cover: The American Bird Conservancy Guide to Bird Conservation

In their recently released book, The American Bird Conservancy Guide to Bird Conservation, ABC changes tack a bit—using what the authors call “conservative” estimates of the outdoor cat population and annual predation rates, for example, to arrive at their figure of “532 million birds killed annually by outdoor cats.” [2] At the same time, they include much of the same misinformation ABC’s been promoting all along. It’s a clever strategy, really: endorsing bogus claims as valid science without having to defend them as such.

In fact, one doesn’t need to get past the book’s preface before realizing the role that science plays—or, more to the point, doesn’t play—at ABC. “We see very few issues resolved through coming to consensus on the science,” writes President and CEO George Fenwick.

“More often, science divides us. So, though we continue to need excellent science, conservationists also need to learn how to better persuade, use media effectively, and connect birds to the human condition, spirituality and ethical values.” [2]

If its section on cats is any indication, The ABC Guide is the manifestation of Fenwick’s philosophy: more style than substance, more sales than science. The authors didn’t even bother with citations and references, suggesting to readers, perhaps, that The ABC Guide is the last word on the subject. Where free-roaming cats are concerned, though, ABC has precious few answers—in part because they (still) aren’t asking the right questions.

Outdoor Cats
Referring to unattributed 2007 data, the authors of The ABC Guide—Daniel Lebbin, Michael Parr, and George Fenwick—claim that 43 percent of pet cats “have access to the outdoors.” [2] But, according to American Pet Products Association (APPA) 2008 National Pet Owners Survey, 64 percent of cats are indoor-only during the daytime, and 69 percent are kept in at night [3].

Other surveys have yielded similar results, and also indicate that, of those cats that are allowed outdoors, approximately half were outside for three hours or less each day [4, 5]. For Lebbin et al., though, these part-timers are no different from their feral relatives. Of which, “there are 60–120 million,” according to the authors. [2]

Where this figure comes from is anybody’s guess. It’s substantially higher than any other estimates I’ve seen, with one notable exception—a statement made earlier this year by an ABC official (more on that in a moment).

Feral Cat Numbers
Very little exists in terms of credible population estimates for feral cats. There are, however, many unsubstantiated claims.

Among the most popular for those interested in big numbers is the first line from David Jessup’s ironically titled 2004 paper “The welfare of feral cats and wildlife” (ironic because his “concerns” for the welfare of these cats are so plainly disingenuous): “There are an estimated 60 to 100 million feral and abandoned cats in the United States.” [6] As to the origins of Jessup’s “estimate,” again, it’s anybody’s guess, as he offers no reference.

Based on the results of a 1999 telephone survey of Alachua County, Florida, residents, Levy et al. estimated that the population of free-roaming cats represented approximately 44 percent of the county’s total population of cats. [7] Other researchers have reported similar figures for nationwide estimates. [8] By way of comparison, ABC’s estimate represents 39–56 percent of the overall population of cats in the U.S. (based on APPA’s latest figures for pet cats).

On the other hand, 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. [9] 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.” [10] 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.” [10]

Population Increase
Earlier this year, ABC’s Senior Policy Advisor, Steve Holmer, told the Los Angeles Times, “The latest estimates are that there are about . . . 160 million feral cats [nationwide].” When pressed for details, Holmer referred me to Nico Dauphine and Robert Cooper’s 2009 Partners In Flight Conference paper. Which, as it turns out, leads right back to ABC and their Cats Indoors! campaign.

Dauphine and Cooper begin their adventure in creative accounting with Jessup’s unattributed 100 million, and add to it the number of owned cats they describe as “free-ranging outdoor cats for at least some portion of the day.” [11] For which they turn to Linda Winter, former director of Cats Indoors!, and her 2004 paper in which she reports the findings of a 1997 telephone survey (commissioned by ABC) of cat owners. According to Winter, “66 percent of cat owners let their cats outdoors some or all of the time.” [12]

In fact, the survey—as reported in ABC’s brochure “Human Attitudes and Behavior Regarding Cats”—indicated that “35 percent keep their cats indoors all of the time” and “31 percent 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), but it’s difficult not to see this as deliberately misleading on Winter’s part.

In any case, results of other surveys (described previously) suggest quite convincingly that outdoor access for the vast majority of pet cats is really very limited. Nevertheless, Dauphine and Cooper persist, arriving at a staggering “117–157 million free-ranging cats.” [11] Holmer, in turn, rounds off the upper limit, “scrubs” the pet cats from the calculation by calling them all ferals, and gets the bogus figure printed in the Times. (Gold star for Holmer!)

Lebbin et al. don’t go that far, but their “most conservative estimate of outdoor and feral cats in the U.S.”—95 million—is, given its shaky origins, no more valid than Dauphine and Cooper’s.

Predation
According to The ABC Guide, “all outdoor cats hunt and kill birds (20­–30 percent of cat prey) and other small animals.” [2] No study I’m aware of has demonstrated that all cats hunt. On the contrary, some research suggests that less than half of outdoor cats hunt. Figures as low as 36–56 percent have been reported by researchers in Australia, for example. [13]

In the UK, Baker, Bentley, Ansell, and Harris reported that 77 cats returned a total of 212 prey items to 52 Bristol households participating in their pilot study, but “in each sampling period, the majority of cats (51–74 percent) failed to return any prey.” [14] The subsequent 12-month study (this time involving 186 Bristol households, 275 cats, and 495 prey items) found a similar level of apparent non-hunters: roughly 61 percent. [15]

Woods, McDonald, and Harris, also working in the UK, found that, although 91 percent of cats returned at least one item, “approximately 20–30 percent of cats brought home either no birds or no mammals.” [16] And Churcher and Lawton’s yearlong “English Village” study (involving approximately 70 cats and 1,090 documented prey items) found that that 8.6 percent of cats brought home no prey [17] (though the authors don’t specify the percentage of cats that returned no birds).

And while it’s true that cats are unlikely to return home with all they prey they catch, it’s equally true that they will bring home items they didn’t kill. Very little is known about the extent of either phenomenon, however. (Carol Fiore’s [18] attempt to unravel this mystery is plagued by methodological missteps and obvious bias; William George’s [19] comments are often interpreted as suggesting that cats return only half of what they catch, though this is incorrect.)

The Diet of Cats
The idea that birds make up 20–30 percent of the diet of free-roaming cats is one that ABC has been promoting since 1997, when they launched Cats Indoors! But it’s no more valid now than it was then.

According to ABC’s brochure, “Domestic Cat Predation on Birds and Other Wildlife” (downloadable from their website), “extensive studies of the feeding habits of domestic, free-roaming cats… show that approximately… 20 to 30 percent [of their diet] are birds.” Ellen Perry Berkeley carefully examined—and debunked—this claim in her book, TNR Past Present and Future: A history of the trap-neuter-return movement, noting that ABC’s 20–30 percent figure wasn’t based on “extensive studies” at all. [10]

In fact, just three sources were used: the now-classic “English Village” study by Churcher and Lawton [11], the infamous “Wisconsin Study,” and researchers Mike Fitzgerald and Dennis Turner’s contribution to The Domestic Cat: The Biology of Its Behaviour. [12]

As Berkeley points out, combining or comparing data from these three sources is entirely inappropriate. Both the English Village and Wisconsin studies report the percentage of birds returned as a portion of the “total catch,” whereas Fitzgerald reports percentage by frequency (i.e., the occurrence of birds in the stomach contents or scats of free-roaming cats).

To put this into more familiar terms, consider coffee consumption. According to the 2009 National Coffee Drinking Trends Study, 54 percent of American adults drink coffee daily—54, then, is the percentage by frequency. To say that coffee makes up 54 percent of our dietary intake—essentially ABC’s interpretation—is obviously a gross exaggeration of consumption levels. (Neither measure says anything about the supply of coffee, of course.)

Nevertheless, 13 years after ABC first published its report—and six years after Berkeley exposed the error publicly in TNR—the myth persists. So much for ABC’s commitment, spelled out in the book’s section on threats, to “address all of the major threats responsible for killing large numbers of birds, using the best information and research available, while promoting further research and monitoring where it is most needed.” [2]

Which, in turn, raises serious questions about the integrity of ABC and the people running it.

Declawed Cats
Citing Fiore’s thesis research, Lebbin at al. conclude, “de-clawed cats kill as many birds as cats with claws.” [2] Fiore herself is equally confident:

“There were seven declawed cats in the study and all but one took birds (giving a figure of 86 percent); the top predator cat was declawed. Declawing cats appears to have no effect whatsoever on the ability to hunt birds.” [18]

But, both ABC and Fiore leave out some critical details. There were, after all, only 41 cats involved in the study—hardly the kind of sampling required to make such sweeping statements.

A closer look reveals that the declawed cats were apparently responsible for killing an average of 3.6 birds/cat/year while the cats with claws had an average of 3.0. Does this mean that the declawed cats are actually superior hunters compared to the other cats? Hardly.

In addition to the sampling issue, there’s the problem inherent in using the average to describe highly skewed distributions (many cats catching few prey, while few cats catch many prey). In such instances, it’s more appropriate to use median values, which better represent “average” hunting success. [20] Doing so yields estimates of 1 bird/cat/year for the declawed cats vs. 2 birds/cat/year for the cats with claws.

So, declawed cats kill only half as many birds as those with claws? I’ll leave such indefensible claims to others.

Now, to be clear: I’m no advocate of declawing. Nor do I think it’s in the best interest of pet cats to be outdoors—especially those without claws. My point here is merely to demonstrate the flaws in ABC’s deceptively straightforward assertion; once again, ABC is more interested in a good story than they are in good science. (Their comment about declawed cats is precisely the kind of sound-bite that is easily picked up by the media, and repeated so widely that it becomes nearly impossible to trace—never mind untangle.)

Cats and Birds
As evidence of the “variable predation rates by cats,” [2] The ABC Guide refers to just four studies. And, although no citations are included, people familiar with the literature will recognize the numbers and locations immediately.

  1. From Christopher Lepczyk’s dissertation work, the authors somehow extract a figure of 35.5 birds/cat/year, near the low end of Lepczyk’s own estimate of “between 0.7 and 1.4 birds per week.” [21] But Lepczyk’s research suffers from a range of problems—both in terms of his methods and analysis—that inflate his estimated predation rates. (Interestingly, ABC’s Fenwick and Winter are among those Lepczyk thanks “for helpful and constructive reviews” in the Acknowledgements section.)
  2. Another of the predation rates included in The ABC Guide is the more moderate 15 birds/cat/year from Crooks and Soulé’s 1999 paper [22]. But here, too, there are flaws that lead to bloated predation levels.Like Lepczyk, Crooks and Soulé asked residents to estimate annual levels of prey returned home by their cats (in contrast to some studies in which actual prey items are recorded and/or collected). But such guesswork becomes less accurate as estimates increase. David Barratt found that “predicted rates of predation greater than about ten prey per year generally over-estimated predation observed” [20]. At the levels reported by Crooks and Soulé—an average of 56 total prey items (including birds, mammals, etc.) per year—predicted rates were often twice actual predation rates.

    Also, Crooks and Soulé seem (not enough detail is provided in their paper to be certain) to have used a simple average in their calculations, perhaps doubling true predation levels. Taken together, these factors suggest that actual predation levels might be just a quarter of those suggested by Crooks and Soulé.

  3. The third study—easily the most rigorous of the four—with a predation rate of 9.6 birds/cat/year, comes from Woods et al. The researchers, having recruited study participants solely from The Mammal Society, allow that they “may have focused on predatory cats,” and ask that their results be “treated with requisite caution.” [16] They also make clear that their estimated predation rates “do not equate to an assessment of the impact of cats on wildlife populations” [16] (more on that shortly)
  4. Finally, there is the—seemingly inevitable—reference to the Wisconsin Study, though for some reason (again, without explanation) Lebbin et al. have adjusted Coleman and Temple’s figures of 28–365 birds/cat/year downward: “between 5.6 and 109.5.” [2]In this case, the details hardly matter. The Wisconsin Study isn’t actually a study at all; no predation data or findings were ever published. Coleman and Temple’s “estimates”—widely circulated as valid research, thanks in part to ABC—were nothing more than back-of-the-envelope calculations. “Our best guesses,” as the authors themselves admit, “at low, intermediate and high estimates of the number of birds killed annually by rural cats in Wisconsin.” [23]

    “Those figures were from our proposal,” Temple told The Sonoma County Independent. “They aren’t actual data; that was just our projection to show how bad it might be.” [24]

    Sixteen years later, though, ABC is still trying to make “actual data” out of “not actual data.” (Granted, they have backed off from Coleman and Temple’s high estimate, but no mathematical adjustments can transform these flawed, biased guesses into valid research findings.)

Cats as Hunters
Contrary to popular myth, evidence suggests that cats are not quite the hunters they’ve been made out to be. Fitzgerald and Turner suggest that the hunting behavior of cats leads to many “failures,” and, as a result, “many cats soon give up bird hunting altogether.” [25]

“Primarily, all cats hunt both birds and rodents with equal zeal,” observed German zoologist Paul Leyhausen, “and many obviously prefer eating birds.” But, argues Leyhausen (1916–1998), who spent the bulk of his career studying the behavior of cats, “they cannot catch them as easily, and for this reason with increasing experience may soon give up hunting birds.” [26]

“However, our town cats today are often compelled, because of the almost total absence of rodents in their territory to concentrate on chasing birds in order to discharge their pent-up hunting propensities. Even in these circumstances, however, cats are not capable of seriously endangering the songbird population of a substantial area. They almost always catch only old, sick or young specimens. But three quarters of the young birds must perish anyway, since the size of the population in an area remains fairly constant on an average over the years… During years in the field I have observed countless times how cats have caught a mouse or a rat and just as often how they have stalked a bird. But I never saw them catch a healthy songbird that was capable of flying. Certainly it does happen, but, as I have said, seldom. I should feel sorry for the average domestic cat that had to live solely on catching birds.” [26]

Although few predation studies have examined the hunting behavior of cats belonging to managed colonies, those that have are revealing. Reporting on their study of free-roaming cats in Brooklyn, Calhoon and Haspel write: “Although birds and small rodents are plentiful in the study area, only once in more than 180 [hours] of observations did we observe predation.” [27]

Castillo and Clarke, though highly critical of TNR (“This method is not an effective means to control the population of unwanted cats and confirms that the establishment of cat colonies on public lands encourages illegal dumping and creates an attractive nuisance.” [28]), documented little predation in the two Florida parks they used for their study (the focus of which was TNR efficacy, not predation). Over the course of approximately 300 hours of observation (this, in addition to “several months identifying, describing, and photographing each of the cats living in the colonies” [28] prior to beginning their research), Castillo and Clarke “saw cats kill a juvenile common yellowthroat and a blue jay.” [28]

“Cats also caught and ate green anoles, bark anoles, and brown anoles. In addition, we found the carcasses of a gray catbird and a juvenile opossum in the feeding area.” [28]

Another study conducted in a public park, this one in Alameda County, California, also reported low levels of apparent predation of birds (though researcher Cole Hawkins makes every attempt to suggest otherwise). Of 120 scat samples found by searching the “cat area” of Hawkins’ study site, “65 percent were found to contain rodent hair and 4 percent feathers.” [2] This finding comes toward the end of the study, when the cat population was at its greatest (22 were sighted)—and still, only 4 percent contained feathers. And this could easily represent one cat and one bird (and, strictly speaking, even this is not evidence of actual predation, as the bird(s) could have been scavenged).

Impact
To arrive at their figure of “532 million birds killed annually by outdoor cats,” Lebbin et al. multiply “the most conservative predation rate (5.6 birds per cats per year) by the most conservative estimate of outdoor and feral cats in the U.S. (95 million).” [2] They go on to suggest that “the actual number” is “likely… much higher,” [2] though, of course, they ignore or overlook all the errors and misrepresentations bound up in their basic calculation.

Even setting all that aside, the question remains: What impact does predation by cats have on bird populations?

Islands and Continents
Here, the authors focus mostly on the extinction of seabirds linked to the presence of feral cats on islands. I’m only vaguely familiar with the examples they cite, but if the case of the Stephens Island Wren is any indication, the stories are far more complex than ABC suggests. [see, for example, 29 and 30]

But, as Fitzgerald and Turner point out, “because the range of prey available on islands differs markedly from that on the continents the two groups, continents and islands, are treated separately.” [25]

And when it comes to the impact of cats on continental bird populations, ABC highlights rare and endangered species—but ignores entirely two key points. First, as was mentioned previously, even high rates of predation do not equate to population declines.

Referring to the estimated 30 percent of House Sparrow mortality attributed to cat predation in the English Village study, Gary Patronek emphasizes the importance of viewing such predation in the larger context. “When the birds were counted,” writes Patronek, former Director of the Center for Animals and Public Policy at the Cummings School, and one of the founders of the Hoarding of Animals Research Consortium, “they represented the postwinter population prior to hatching of spring chicks. By the year’s end, the actual sparrow population in the village numbered in the thousands, and the 130 birds caught represented about 5 percent of that number.” [31]

Compensatory vs. Additive Predation
Then there is the critical distinction between compensatory and additive predation, something Churcher himself alluded to: “I don’t really go along with the idea of cats being a threat to wildlife. If the cats weren’t there, something else would be killing the sparrows or otherwise preventing them from breeding.” [32]

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). [15, 33] 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. Relative to population impacts, then, the “accounting” of bird kills is far more complex than ABC suggests.

Additional Evidence
Many researchers have disputed the kind of broad, overreaching claims Lebbin et al. make about the impact of cats on bird population (and wildlife in general).

Biologist C.J. Mead, 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.” [34]

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.” [25]

In the context of TNR, however, focusing on such figures may be missing the point. “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,” writes Patronek, “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.” [35]

“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 species is an imprecise and contentious process at best. Additional research is clearly needed concerning the welfare of these cats.” [35]

Trap-Neuter-Return
“Many well-intentioned but misguided people,” write Lebbin et al. “exacerbate feral cat problems through a technique called Trap, Neuter, Release (TNR), whereby colony cats are caught, spayed or neutered, and then returned to colonies to be fed by volunteers.” [2] Here, the authors trot out a classic verbal swipe, using the term Release instead of Return, implying a certain lack of planning, or even abandonment (with its legal implications).

They also imply that ABC is a resource for the “misguided.”

Stay Cats (Peep Show)
From The ABC Guide, the caption reads: “Managed feral cat colonies are a hazard to birds and attract the dumping of additional unwanted cats.” In fact, the photographer, Tina Lorien, tells me that these cats were photographed on the Island of Crete, where, it seems, even spayed/neutered pet cats are rather rare.

“Despite its apparent appeal,” Lebbin et al. continue, “few colonies managed under this system shrink, as the program takes more time than most volunteers are able to give, some cats are never caught, and the colonies often become dumping grounds for more unwanted cats.” [2]

Resources
Their claim that TNR programs are ineffective due to limited resources is unsubstantiated. More important, though, they ignore the fact that any feral cat management program is resource-intensive (as is any conservation effort, of course). Several successful TNR programs have been documented (see below), and countless more operate quietly, out of the spotlight.

It’s important to point out, too, that TNR is typically funded through private donations and the out-of-pocket purchases of volunteers. Trap-and-kill, on the other hand, is more likely to rely entirely on local tax dollars.

Sterilization
Their suggestion that all the cats need to be sterilized also lacks support. One often-cited population modeling study—included here more as a reference point than anything else—found that, in order to reduce colony population, approximately 75 percent of fertile cats would need to be sterilized. [36] However, this figure from Andersen, Martin, and Roemer takes into account no adoptions, though the authors point out that adoptions “are similar in effect to euthanasia because these cats are permanently removed from the free-roaming cat population.” [36]

Nor do Andersen et al. consider emigration between cat colonies, though they concede that “a substantial number of owned cats are reported to be adopted strays.” [36] “Substantial” is right—in 2003, Clifton suggested that “up to a third of all pet cats now appear to be recruited from the feral population.” [10]

TNR Successes
Though Lebbin et al. refuse to acknowledge it, TNR has had its share of successes. A 10-year TNR program in Rome, for example, yielded a “16–32 percent decrease on total cat number” across 103 managed colonies. [37] Detractors [38] like to focus on authors’ suggestion that “all these efforts without an effective education of people to control the reproduction of house cats (as a prevention for abandonment) are a waste of money, time and energy.” [37]

In fact, given the 21 percent rate of immigration “due to abandonment and spontaneous arrival,” [37] this colony reduction is quite remarkable. And, as Julie Levy, Maddie’s Professor of Shelter Medicine in the University of Florida’s College of Veterinary Medicine, points out, “such a decline is still beneficial to wildlife if no better alternative is available.” [39] (The “alternatives” ABC proposes—outlined below—are, at best, exactly that: no better.)

Levy, Gale, and Gale reported a 66 percent decline in the population of managed colonies on the University of Central Florida campus between 1991 and 2002, despite the arrival of stray or abandoned cats. [40] (In their paper, Levy et al. cite several other success stories.) And, in their telephone survey of 101 north-central Florida colony caretakers, Centonze and Levy reported “a 27 percent decrease in mean colony size within less than one year of beginning neutering.” [41]

One of the best-known TNR programs is ORCAT, run by the Ocean Reef Community Association, which, according to a 2004 paper, had reduced “overall population from approximately 2,000 cats to 500 cats.” [42] According to the ORCAT website, the population today is approximately 350, of which only about 250 are free-roaming.

Any TNR program contends with the unfortunate (and illegal) dumping of cats. But to suggest that TNR invites abandonment of cats is ridiculous. I’ve seen no research supporting such a claim. If people are determined to abandon their pet cat(s), I fail to see how the presence or absence of a nearby TNR program will affect that decision. On the other hand, cats dumped near a managed colony are far more likely to be adopted and/or sterilized—thereby mitigating their potential impact on the overall population of unowned cats.

Finally, it’s important to note that, although rapid decline—and eventual elimination through attrition—of managed colonies is the goal of TNR (and apparently the only acceptable outcome for the authors of The ABC Guide), reduced growth is not without its benefits. “Population stabilization,” writes Levy, is “a valid metric given that the status quo for unsterilized cats is rapid population growth.” [39]

Alternatives to TNR
Given their ongoing criticism of TNR, one might expect ABC to offer an alternative method of feral cat management—an approach against which to measure TNR (and against which TNR would, presumably, prove inferior). For the most part, though, ABC sidesteps the issue.

“Neutering and spaying pet cats,” write Lebbin et al., “is a humane method for reducing cat over-population.” True enough, but that doesn’t address the sizable population of unowned cats. Although The ABC Guide calls for readers to “make TNR and the feeding of cat colonies illegal,” [2] there’s no recommendation for what should be done with all of these cats.

I put this question to Lebbin and Parr during an ABC webinar celebrating the launch of the book earlier this month. “What we recommend,” said Parr, Vice President of ABC, “as an alternative to [TNR], is not abandoning cats in the first place.” Again, I don’t think there’s any disagreement on this point. Parr continued:

“Other options would be to house those cats in shelters or outdoor sanctuaries which could be managed. Clearly, it’s a huge problem, and the solutions to this are going be things we going to have to work together on for a long period of time, but certainly that would be my first reaction to that question.”

Really, we’re back to sanctuaries? Is this the best ABC has to offer? Almost.

Trap-and-Remove
In their book, Lebbin et al. point out, with obvious pride, that, “By 2004, feral cats had been successfully removed from at least 48 islands worldwide” (there’s another euphemism: removed). [2] A particular “success” is Ascension Island, where, the authors maintain, feral cats had reduced seabird numbers “by 98 percent, from 200 million to 400,000.” [2] As a result of “a multi-year eradication effort that began in 2001,” [2] birds have begun to return.

But, as is often the case, what’s left out of the story is far more interesting than what included.

Detailed accounts of feral cats eradication Marion Island provide a glimpse of the horrors involved. A 1992 paper reports 872 cats shot and 80 more trapped during 14,725 hours of hunting. “Present action” included “mass trapping and poisoning, and the possible use of trained dogs [was] being investigated.” [43] This was after the highly contagious feline panleucopenia virus (feline distemper) had been introduced to the island’s feral cat population, reducing the population by an average 29 percent annually between 1977 and 1982. [44]

On Macquarie Island successful eradication has had “dire” [45] consequences in the form of rapidly increasing rabbit and rodent populations. “In response, Federal and State governments in Australia have committed AU$24 million for an integrated rabbit, rat and mouse eradication programme.” [45]

Given the extent to which conservation efforts backfired on Macquarie Island—less than 50 square miles in size—one can only imagine the consequences and expense (to say nothing of the protests!) of a similar attempt in the continental U.S. But according to ABC, it seems to be either this or sanctuaries—for a population of feral cats they claim to be 60–120 million strong.

(To be fair, Lebbin et al. do offer this concession: “In some cases, invasive or overabundant species may not need to be eradicated, but simply reduced to levels such that they no longer pose a serious threat to native endangered species.” [2] Given their staunch opposition to TNR, however, I suspect this “offer”—which in any case would mean the killing of many millions of cats—does not apply to feral cats.)

The Current Approach
We do have some sense of how ineffective “traditional” feral cat management—a mix of trap-and-kill and inaction—has been. In an interview with Animal Sheltering magazine, Mark Kumpf, President of the National Animal Control Association President from 2007 to 2008, described this approach as “bailing the ocean with a thimble,” suggesting, too, that “the traditional methods that many communities use… are not necessarily the ones that communities are looking for today.” [46]

Clifton goes further, suggesting that trap-and-kill has actually backfired: “Regardless of motive,” writes Clifton, “the effect on the feral cat population replicates natural predation: the most frequent victims are the very young, the old, the disabled, and the ill. The healthiest animals usually escape to breed up to the carrying capacity of the habitat, if they can.” [10]

“Responding to the intensified mortality,” Clifton continues, “felis catus now bears an average litter of four. Nearly seven centuries of killing cats doubled the fecundity of the species.” [10]

Accountability
What Becky Robinson called a “new environmental witch hunt,” [1] I like to think of as a Trojan Horse. Disguised as good advice for responsible cat owners, ABC’s Cats Indoors! campaign has, since 1997, been used more to combat TNR than anything else.

With the publication of The ABC Guide, the authors had a chance to right some past wrongs by coming clean about the research surrounding predation, wildlife impacts, and TNR, as well as the true implications of their call to “make TNR and the feeding of cat colonies illegal.” [2] Instead, they elected for business as usual.

Facts vs. Human Connection
In doing so, ABC missed a golden opportunity to use its enormous influence for moving the discussion forward. (More recently, ABC took another big step backwards by endorsing a deeply flawed and irresponsible paper released by the University of Nebraska-Lincoln, once again sacrificing their integrity for some easy PR.)

But Fenwick, who’s been President and CEO since ABC’s founding in 1994, doesn’t seem to get it. “What have we learned about the opposition?” he asks rhetorically in the book’s preface.

“For one thing, every point of view has its own science and economics to support its contentions, whether it be pro- or anti- pesticide use, free-roaming cats, bird collisions with glass or towers, conflicts with fisheries, land conversion, wind energy, mining, timbering, climate change, or any other issue we consider in addressing bird conservation…” [2]

Fenwick seems to be suggesting that “the opposition” has its own science and economics, whereas ABC has, on its side: Science and Economics (a truly untenable position, in light of a recent ABC press release).

“Facts alone will not win these battles,” he continues, “but human connection might.”

Communication vs. Misinformation
I have to agree with Fenwick that facts alone are insufficient to engage the general public. It’s difficult, for instance, to convey the critical nature of climate change in terms of ocean temperatures rising a couple of degrees Celsius (a figure I use here only to make a point). Explain to people how deep the water may rise in their city or neighborhood, however, and you’re liable to get their attention.

But that’s not what ABC is doing. They have effectively dismissed any and all rigorous science, choosing instead to broadcast as loudly as possible their increasingly dire message—in spite of the science.

Fenwick’s analogy is not climate change, but human health and welfare:

“…no matter the issue, our opposition will unfailingly question our priorities. So, they ask, ‘Why are you blaming __________ when we know habitat loss is the real problem?’ when I am asked these questions, I reply first that we continue to add to our base of knowledge and thus improve decisions affecting bird populations; second, if winning the debate translates to financial gain for the debater, then that position cannot be truly unbiased; and third, isn’t it analogous that if heart disease is the greatest mortality factor in our species, then why do we spend so much money combating cancer and other diseases, poverty and hunger? Solving any single problem—for birds or humans—is insufficient for our cause. Thoughtful people understand that it is critical that we fight for birds and humans across the full, broad front of issues.” [2]

Fenwick’s medical research analogy is an interesting one, but not in the way he intended. Actually, I’m reminded of David Freedman’s profile of John Ioannidis, professor at the University of Ioannina medical school’s teaching hospital, which appeared in last month’s Atlantic. In the piece, Freedman describes a provocative 2005 article that garnered Ioannidis worldwide attention:

“The article spelled out his belief that researchers were frequently manipulating data analyses, chasing career-advancing findings rather than good science, and even using the peer-review process—in which journals ask researchers to help decide which studies to publish—to suppress opposing views.” [47]

Obviously not the image Fenwick was trying to convey—but far more fitting.

Attacking “the full, broad front of issues” simultaneously makes perfect sense, but promoting erroneous and deceptive scientific claims in order to marshal the support necessary is unethical, plain and simple.

We’re not talking about cancer research distracting us from research into heart disease, to use Fenwick’s metaphor. No, what he and ABC are doing—in their relentless persecution of free-roaming cats, at least—is akin to funneling critical resources into the bottling and marketing of snake oil:

There’s no science behind it, and no remedy in its consumption—whatever the dosage.

Literature Cited
1. Sterba, J.P. (2002, October 11). Tooth and Claw: Kill Kitty? Wall Street Journal, p. A.1,

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. APPA, 2009–2010 APPA National Pet Owners Survey. 2009, American Pet Products Association: Greenwich, CT.

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. http://avmajournals.avma.org/doi/abs/10.2460/javma.2003.222.1541

5. Lord, L.K., “Attitudes toward and perceptions of free-roaming cats among individuals living in Ohio.” Journal of the American Veterinary Medical Association. 2008. 232(8): p. 1159-1167. http://avmajournals.avma.org/doi/abs/10.2460/javma.232.8.1159

6. 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

7. Levy, J.K., et al., “Number of unowned free-roaming cats in a college community in the southern United States and characteristics of community residents who feed them.” Journal of the American Veterinary Medical Association. 2003. 223(2): p. 202-205. http://avmajournals.avma.org/doi/abs/10.2460/javma.2003.223.202

8. Patronek, G.J. and Rowan, A.N., “Editorial: Determining dog and cat numbers and population dynamics.” Anthrozoös. 1995. 8(4): p. 199–204.

9. 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.

10. 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.

11. Dauphine, 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. http://www.pwrc.usgs.gov/pif/pubs/McAllenProc/articles/PIF09_Anthropogenic%20Impacts/Dauphine_1_PIF09.pdf

12. Winter, L., “Trap-neuter-release programs: the reality and the impacts.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1369-1376. http://avmajournals.avma.org/doi/abs/10.2460/javma.2004.225.1369

13. Fougere, B. Cats and wildlife in the urban environment—A review. in Urban Animal Management Conference. 2000.

14. 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. http://dx.doi.org/10.1111/j.1365-2907.2005.00071.x

15. 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

16. 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. http://dx.doi.org/10.1046/j.1365-2907.2003.00017.x

17. Churcher, P.B. and Lawton, J.H., “Predation by domestic cats in an English village.” Journal of Zoology. 1987. 212(3): p. 439-455. http://dx.doi.org/10.1111/j.1469-7998.1987.tb02915.x

18. Fiore, C.A., The Ecological Implications of Urban Domestic Cat (Felis catus) Predation on Birds In the City of Wichita, Kansas, in College of Liberal Arts and Sciences. 2000, Wichita State University: Wichita, Kansas.

19. George, W., “Domestic cats as predators and factors in winter shortages of raptor prey.” The Wilson Bulletin. 1974. 86(4): p. 384–396. http://elibrary.unm.edu/sora/Wilson/v086n04/p0384-p0396.pdf

20. 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.

21. 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. http://www.sciencedirect.com/science/article/B6V5X-48D39DN-5/2/d27bfff8454a44161f8dc1ad7cc585ea

22. Crooks, K.R. and Soule, M.E., “Mesopredator release and avifaunal extinctions in a fragmented system.” Nature. 1999. 400(6744): p. 563–566. http://www.nature.com/nature/journal/v400/n6744/abs/400563a0.html

23. Coleman, J.S. and Temple, S.A., On the Prowl, in Wisconsin Natural Resources. 1996, Wisconsin Department of Natural Resources: Madison, WI. p. 4–8. http://dnr.wi.gov/wnrmag/html/stories/1996/dec96/cats.htm

24. Elliott, J. (1994, March 3–16). The Accused. The Sonoma County Independent, pp. 1, 10.

25. 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.

26. Leyhausen, P., Cat behavior: The predatory and social behavior of domestic and wild cats. Garland series in ethology. 1979, New York: Garland STPM Press.

27. Calhoon, R.E. and Haspel, C., “Urban Cat Populations Compared by Season, Subhabitat and Supplemental Feeding.” Journal of Animal Ecology. 1989. 58(1): p. 321–328.

28. Castillo, D. and Clarke, A.L., “Trap/Neuter/Release Methods Ineffective in Controlling Domestic Cat “Colonies” on Public Lands.” Natural Areas Journal. 2003. 23: p. 247–253.

29. Galbreath, R., “The tale of the lighthouse-keeper’s cat: Discovery and extinction of the Stephens Island wren (Traversia lyalli).” Notornis. 2004. 51: p. 193–200.

30. Medway, D.G., “The land bird fauna of Stephens Island, New Zealand in the early 1890s, and the cause of its demise.” Notornis. 2004. 51: p. 201–211.

31. 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.

32. n.a., What the Cat Dragged In, in Catnip. 1995, Tufts University School of Veterinary Medicine: Boston, MA. p. 4–6.

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

34. 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

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

36. 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. http://avmajournals.avma.org/doi/abs/10.2460/javma.2004.225.1871

37. 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. http://www.sciencedirect.com/science/article/B6TBK-4M33VSW-1/2/0abfc80f245ab50e602f93060f88e6f9

38. 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.

39. Levy, J.K., Comments Re: “Critical Assessment”, Personal Communication. July 21, 2010.

40. 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. http://avmajournals.avma.org/doi/abs/10.2460/javma.2003.222.42

41. Centonze, L.A. and Levy, J.K., “Characteristics of free-roaming cats and their caretakers.” Journal of the American Veterinary Medical Association. 2002. 220(11): p. 1627-1633. http://avmajournals.avma.org/doi/abs/10.2460/javma.2002.220.1627

42. Levy, J.K. and Crawford, P.C., “Humane strategies for controlling feral cat populations.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1354-1360. http://avmajournals.avma.org/doi/abs/10.2460/javma.2004.225.1354

43. Bloomer, J.P. and Bester, M.N., “Control of feral cats on sub-Antarctic Marion Island, Indian Ocean.” Biological Conservation. 1992. 60(3): p. 211-219. http://www.sciencedirect.com/science/article/B6V5X-48XKBM6-T0/2/06492dd3a022e4a4f9e437a943dd1d8b

44. Rensburg, P.J.J.v., Skinner, J.D., and van Aarde, R.J., “Effects of Feline Panleucopaenia on the Population Characteristics of Feral Cats on Marion Island.” Journal of Applied Ecology. 1987. 24: p. 63–73.

45. Bergstrom, D.M., et al., “Indirect effects of invasive species removal devastate World Heritage Island.” Journal of Applied Ecology. 2009. 46(1): p. 73-81. http://dx.doi.org/10.1111/j.1365-2664.2008.01601.x

46. Hettinger, J., Taking a Broader View of Cats in the Community, in Animal Sheltering. 2008. p. 8–9. http://www.animalsheltering.org/resource_library/magazine_articles/sep_oct_2008/broader_view_of_cats.pdf

47. Freedman, D.H., Lies, Damned Lies, and Medical Science, in The Atlantic. 2010: Boston. p. 76–86. http://www.theatlantic.com/magazine/print/2010/11/lies-damned-lies-and-medical-science/8269/

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.

Adult Supervision Required III

As I dig deeper into “Feral Cats and Their Management,” I continue to undercover discrepancies between the story Hildreth, Vantassel, and Hygnstrom are telling and what’s actually in the literature.

As I pointed out in my first post on the topic, Olof Liberg did not differentiate between native and non-native prey, as Hildreth, Vantassel, and Hygnstrom suggest. In fact, his reference to “natural prey” [1] was only to distinguish between food provided by humans and any wildlife that cats might consume.

While revisiting Liberg’s paper, though, I found something far more intriguing: it appears Hildreth, Vantassel, and Hygnstrom never made it past the abstract.

In their report, the authors write: “The diets of well-fed house-based cats in Sweden consisted of 15 percent to 90 percent native prey, depending on availability.” [2] But what Liberg is describing here is merely the range of prey brought in by all of the cats in the study, 80–85 percent of which were “well-fed house-based” (the others feral).

Liberg (1984) Figure 1

Moving beyond the abstract, however, the story gets even better. Averaged annually, wildlife makes up just 25–30 percent of the diet of the owned cats (see Fig. 1). Rabbits, being abundant in the area, make up the bulk, with birds—which, we’re made to understand, are of greatest concern for Hildreth, Vantassel, and Hygnstrom—comprising a couple percent at most.

*     *     *

Considering the brevity of the report’s Issues and Impacts section (roughly the same space as was allotted to lethal control methods), the authors managed to squeeze in a surprising amount of misinformation.

Literature Cited
1. Liberg, O., “Food Habits and Prey Impact by Feral and House-Based Domestic Cats in a Rural Area in Southern Sweden.” Journal of Mammalogy. 1984. 65(3): p. 424-432. http://www.jstor.org/stable/1381089

2. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. http://elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

Adult Supervision Required II

In my haste to get my previous post online, I neglected to address a critical point (later brought to my attention by a particularly helpful reader). So, a brief follow-up…

In “Feral Cats and Their Management,” the authors point out—correctly, in this case—that “most feral cats (62 percent to 80 percent) tested positive for toxoplasmosis.” [1] But the rate of cats testing positive—or seroprevalence—is 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.” [2]

“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).

And so, any argument for killing feral cats based on their high T. Gondii seroprevalence is deeply flawed (and, it should be obvious, on very shaky ground ethically). According to this line of reasoning, we might well consider quarantining humans testing positive for flu antibodies.

TNR: The Solution, Not the Problem
If T. gondii in feral cats is really the concern, then the focus should be on removing young cats from “high-risk” environments. Sound familiar? That’s a significant part of what TNR programs do.

As Dubey and Jones point out, T. gondii prevalence tends to be higher in feral cats than pet or owned cats. [2] So, getting kittens adopted—a key feature of TNR—reduces the likelihood of their becoming T. gondii “contributors” in the future.

And adoption numbers seem to be significant. In 2003, Merritt Clifton of Animal People, an independent newspaper dedicated to animal protection issues, suggested that “up to a third of all pet cats now appear to be recruited from the feral population.”

One can actually make the argument that TNR—dismissed more or less out of hand by Hildreth, Vantassel, and Hygnstrom—may well be the best defense currently available against the spread of Toxoplasmosis (not only in terms of stabilizing/reducing population numbers overall, but also in that it reduces number of kittens potentially exposed to T. gondii).

Hunting for Scapegoats
Finally, one more interesting note from Dubey and Jones (whose paper is referenced in “Feral Cats and Their Management”):

“In addition to live prey, eviscerated tissues (gut piles) from hunted deer and black bears would be a source of infection for wild cats… Prevalence of T. gondii in wild game and venison in the USA is very high and hunters need to be aware of the risk of transmission of infection to humans and, more importantly, spread of infection in the environment. The viscera of hunted animals need to be buried to prevent scavenging by animals, especially cats.” [2]

But Hildreth et al. prefer to focus (or, take aim, as the case may be) solely on feral cats. Though their motives aren’t clear to me, there’s no doubt whatsoever that they have little understanding of the key issues surrounding TNR—never mind the relevant science.

Literature Cited
1. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. http://elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

2. 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

3. 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.

Adult Supervision Required

“Have you seen this already? This is awful.”

That’s what somebody posted on the Vox Felina Facebook page late last night—along with a link to an MSNBC news story. The headline was an attention-getter, no doubt about it: “Report: Kill feral cats to control their colonies.”

But beyond that, MSNBC had practically no details. A little digging around, however, led me to New England Cable News (NECN), which has the complete story.

“The report began in an undergraduate wildlife management class, with students writing reports on feral cats based on existing research. The students’ professor and other [University of Nebraska] researchers then compiled the report from the students’ work.” [1]

“Feral Cats and Their Management” claims, straightforwardly enough, to provide “research-based information on the management of feral cats.” [2] Management, in this case, meaning—as is so often the case in such contexts—killing, extermination, eradication, and so forth. Detailed advice is provided (e.g., “Body-gripping traps and snares can be used to quickly kill feral cats”).

And research? In this case, nothing more than a cursory review of all of the usual suspects: Coleman and Temple, Pamela Jo Hatley, Cole Hawkins, The Wildlife Society, Linda Winter. In other words, lots of Kool-Aid drinking.

It’s Like Science, Only Different
Among the research misinterpreted and/or misrepresented (none of which is cited in the text):

“As instinctive hunters, feral cats pose a serious threat to native wildlife, particularly birds.”

It’s no surprise that the authors of the report offer no evidence to support such a sweeping claim. “There are few if any studies,” write Mike Fitzgerald and Dennis Turner in their contribution to The Domestic Cat: The biology of its behaviour, “apart from island ones that actually demonstrate that cats have reduced bird populations.” [3]

Biologist C.J. Mead, reviewing the deaths of “ringed” (banded) birds reported by the British 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.” 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.” [4]

The German zoologist Paul Leyhausen (1916–1998), who spent the bulk of his career studying the behavior of cats, found that cats, frustrated by the difficulties of catching them, “may soon give up hunting birds.” [5]

“During years in the field,” wrote Leyhausen, “I have observed countless times how cats have caught a mouse or a rat and just as often how they have stalked a bird. But I never saw them catch a healthy songbird that was capable of flying. Certainly it does happen, but, as I have said, seldom. I should feel sorry for the average domestic cat that had to live solely on catching birds.” [5]

“Cats kill an estimated 480 million birds per year (assuming eight birds killed per feral cat per year).”

Fitzgerald and Turner (whose work is not referenced in the report) argue that “we do not have enough information yet to attempt to estimate on average how many birds a cat kills each year.” [3] Though, of course, many studies have tried to do exactly that—few, it should be said, involve feral cats.

Unfortunately—and as I have pointed out time and time again—such work typically suffers from a range of methodological and analytical problems (e.g., statistical errors, small sample sizes, and inappropriate/baseless assumptions).

And—as with the UNL report—obvious bias.

“Estimates from Wisconsin indicate that between 500,000 and 8 million birds are killed by rural cats each year in that state…”

How anybody could misquote the numbers from the Wisconsin Study—easily the most widely circulated work on the subject—is a mystery. (On the other hand, the figures were, as Stanley Temple has said, “not actual data” [6] in the first place, so I suppose that does allow for some rather liberal interpretation.)

“The diets of well-fed house-based cats in Sweden consisted of 15 percent to 90 percent native prey, depending on availability.”

How important is it that the prey of feral cats is native, versus non-native? That’s a point of some debate—but not in this case. See, what Liberg actually wrote was this: “Most cats (80-85%) were house-based and obtained from 15 to 90% of their food from natural prey, depending on abundance and availability of the latter.” [7, emphasis mine] He was merely drawing the distinction between food provided by humans and any prey that cats might eat as food.

Liberg goes on to point out that the predation he documented did not, justify a conclusive assessment of the effects of cats on their prey populations, but… indicate[s] that cats by themselves were not limiting any of their prey.” [7] Even high rates of predation do not equate to population declines.

“In California, 67 percent of rodents, 95 percent of birds, and 100 percent of lizards brought home by cats were native species, and native birds were twice as likely to be seen in areas without cats.”

What looks to be truly damning evidence loses much of its impact when it’s seen in context. The reference to Crooks and Soulé’s 1999 paper, for example, omitted the sample size involved: “Identification of 68 prey items returned by cats bordering the fragments indicated that 67% of 26 rodents, 95% of 21 birds and 100% of 11 lizards were native species.” [8] It’s important to note, too, that these researchers asked residents to recall what kind of prey their cats returned—no prey items were collected—thereby raising questions about the accuracy of species attribution.

Furthermore, the cats involved with Crooks and Soulé’s study were all pet cats. How their habits compare with those of feral cats is an open question. Merritt Clifton of Animal People, an independent newspaper dedicated to animal protection issues, suggests, “feral cats appear to hunt no more, and perhaps less, than free-roaming pet cats. This is because, like other wild predators, they hunt not for sport but for food, and hunting more prey than they can eat is a pointless waste of energy.”

The second portion of the quote refers to Cole Hawkins’ PhD dissertation. Hawkins’ research methods and analysis are so problematic that the suggestion of a causal relationship between the presence of cats and the absence of birds (native or otherwise) is highly inappropriate (indeed, Hawkins scarcely investigates predation at all).

Among the key issues: Hawkins had no idea what the “cat” area of his study site was like before the cats were there; he merely assumes it was identical to the “no cat” area in terms of its fauna (though the two landscapes are actually quite different). It’s also interesting to note Hawkins’ emphasis on “the preference of ground feeding birds for the no-cat treatment” while downplaying the fact that five of the nine ground-feeding species included in the study showed no preference for either area. (For a more comprehensive analysis, please see my previous post on the subject.)

“…cats are the most important species in the life cycle of the parasite responsible for toxoplasmosis, and in 3 separate studies, most feral cats (62 percent to 80 percent) tested positive for toxoplasmosis.”

While cats are the “definitive host,” 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.” [9]

“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.” [10]

Toxoplasma gondii has been linked to the illness and death of marine life, primarily sea otters [11], prompting investigation into the possible role of free-roaming (both owned and feral) cats. [12, 13] 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. [13]

However, a 2005 study found that 36 of 50 sea otters from coastal California were infected with the Type X strain of T. gondii [14], a type linked to wild felids (mountain lions and a bobcat, in this case), but not to domestic cats. [13] 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). [15]

[NOTE: Please see follow-up post for additional information about cats and T. gondii.]

“Predation by cats on birds has an economic impact of more than $17 billion dollars [sic] per year in the U.S. The estimated cost per bird is $30, based on literature citing that bird watchers spend $0.40 per bird observed, hunters spend $216 per bird shot, and bird rearers spend $800 per bird released.”

According to this bizarre form of accounting, hunters value an individual bird more than 500 times as much as a birdwatcher does—suggesting, it seems, that dead birds are far more valuable than live birds. This is the kind of estimate that can be developed only through university (or perhaps government) research efforts.

Public Indecency
Stephen Vantassel, a wildlife damage project coordinator who worked on the study, said researchers were aware that some people would be ‘very offended that we offered any type of lethal control method.’ But he said the report was written for public consumption and wasn’t submitted to any science journals for publication.” [1]

For the record, Dr. Vantassel, I’m more offended by the way you’ve allowed such sloppy, grossly irresponsible work to pass for “research.” And the idea that such an undertaking is somehow acceptable because it’s meant for a mass audience is simply absurd!

Naturally, the American Bird Conservancy (ABC) embraced the report immediately, “with one official calling it ‘a must read for any community or government official thinking about what to do about feral cats.’” [1]

“‘Not surprisingly, the report validates everything American Bird Conservancy has been saying about the feral cat issue for many years—namely, TNR doesn’t work in controlling feral cat populations,’ Darin Schroeder, vice president of the Conservation Advocacy for American Bird Conservancy, said Tuesday.”

But validation requires far more than this report provides—beginning with a real interest in scientific inquiry and some basic critical thinking skills. And while we’re at it, a refresher in ethics wouldn’t hurt, either.

*     *     *

In my previous post, I’d indicated that my next post—this post—was going to focus on The American Bird Conservancy Guide to Bird Conservation. Obviously, something came up. Anyhow, the book will keep for a few more days…

Literature Cited
1. n.a. (2010) Report: Kill feral cats to control their colonieshttp://www.necn.com/11/30/10/Report-Kill-feral-cats-to-control-their-/landing_scitech.html?&blockID=3&apID=95afccc4d9564caf8e264f9d087f5732 Accessed December 1, 2010.

2. Hildreth, A.M., Vantassel, S.M., and Hygnstrom, S.E., Feral Cats and Their Managment. 2010, University of Nebraska-Lincoln Extension: Lincoln, NE. http://elkhorn.unl.edu/epublic/live/ec1781/build/ec1781.pdf

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.

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6. Elliott, J. (1994, March 3–16). The Accused. The Sonoma County Independent, pp. 1, 10

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

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10. 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

11. 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

12. 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

13. 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

14. 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

15. 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