Parasite Lost

Until now, my posts have focused almost exclusively on wildlife impacts (real and otherwise) related to predation by cats, a topic I’ll be returning to soon enough. Over the past week or so, however, I’ve been researching the Toxoplasma gondii parasite (another subject that will keep me busy well into the future). As it turns out, there’s big news on the T. gondii front—though in this case, the “news” is actually two years old.

Toxoplasma gondii
Toxoplasma gondii
is found in many mammals and birds, but its definitive host—the animal in which the parasite reproduces—is the cat, both domestic and wild species. Cats pass the mature, infective form of the parasite in their feces—a process called “shedding oocysts.” T. gondii infection, or toxoplasmosis, in humans can be traced to “ingestion of oocyst-contaminated soil and water, from tissue cysts in undercooked meat, by transplantation, blood transfusion, laboratory accidents, or congenitally.” [1]

How often cats shed oocysts, and to what extent, is a complex issue—one I’ll save for later. For now, I will simply note that, in general, it is thought that most cats build up immunity to re-shedding oocysts (though exceptions have been documented in laboratory testing). [2] (For a concise overview of T. gondii’s prevalence in, and risks to, humans, download Toxoplasma gondii: Epidemiology, feline clinical aspects, and prevention.”)

T. Gondii, Cats, and Sea Otters
In recent years, T. gondii has been linked to the illness and death of marine life, primarily sea otters [2], thereby prompting investigation into the possible role of free-roaming (both owned and feral) cats. [3, 4] It’s generally thought that oocysts are transferred from soil contaminated with infected feces to coastal waterways by way of freshwater run-off. [4] And it’s also generally thought that domestic cats are the culprits—or at least it was.

As I was sifting through my growing pile of T. gondii studies, I was rather shocked to find this:

“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.” [4] (italics mine)

Let me explain. There are multiple strains of T. Gondii. Studies of southern sea otters from coastal California found that 36 of 50 otters were infected with the Type X strain. [5] In other words, 72% of the otters were infected with a strain of T. gondii that has yet to be traced to domestic cats.

Now, I’ll be the first to admit that these results are to be treated with caution—as Miller et al. note, “subsequent studies” are in order. For one thing, 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). In addition, this area of research is quite active—and, as this study illustrates, the results can be surprising. Future research intended to confirm or refute this work could just as easily take us off in another direction altogether.

That said, this is still big news. Nearly two years old now, however, it’s not exactly breaking news. So why is this the first I’ve heard about these important findings?

What’s the Story?
For some reason, Miller et al. downplay their findings. Worse, they confuse matters by going into detail about the estimated mass of “feline fecal deposition” created by domestic cats in the communities adjacent to their study site. Suddenly, the focus is back on domestic cats. Given the authors’ findings, I’m not sure how this is relevant, other than as background—previous assumptions being called into question by their results. Perhaps it’s merely the inevitable result of 14 co-authors (one of whom, it should be noted, is David Jessup, of whose work I have been critical in the past) collaborating on a single paper.

But I’m unwilling to give Longcore et al. the same benefit of the doubt. In their essay, Longcore et al. [6] dissemble to such an extent that readers are likely to come away missing the point entirely:

“The large quantity of waste from feral and free-roaming cats containing Toxoplasma oocysts [3, 7] and the correlation between freshwater runoff and toxoplasmosis in marine mammals [8] has led researchers to suspect domestic cats as the source of the infections, although further research is needed to determine the relative importance of native versus exotic felids as sources of this parasite [4].”

While technically correct, Longcore et al. gloss over the fact that, based on the very study they cite, “the relative importance of native versus exotic felids as sources of this parasite” might be something like three-to-one.

And it’s not as if these authors are unwilling to consider speculative findings—such as those by Baker et al. [9] and Hawkins [10]. Longcore et al. even take seriously the Wisconsin Study [11] and its findings that “aren’t actual data.” [12] And they leave out plenty, too—which in the case of the Miller et al. work, might have been a more honorable approach.

Something else they should have omitted:

“Felids, including feral and free-roaming cats, shed Toxoplasma oocysts that infect southern sea otters [8, 5], Pacific harbor seals, and California sea lions.” [6]

In fact, Conrad et al. examined just one harbor seal and one sea lion—and in both cases found the Type X strain of T. gondii. [5] Which, when combined with the results from Miller et al., suggests wild felids as the more likely source, rather than domestic cats.

These two studies not only contradict the specific claims made by Longcore et al., they also challenge the native-good/non-native-bad dichotomy that seems to be at the root of so many feral cat/TNR complaints.

*     *     *

I sent an e-mail to Melissa Miller, lead author of “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,” asking her to comment on my reading of the study. I have not yet received a response.

Literature Cited
1. Elmore, S.A., et al., “Toxoplasma gondii: epidemiology, feline clinical aspects, and prevention.” Trends in Parasitology. 26(4): p. 190-196.

2. Jones, J.L. and Dubey, J.P., “Waterborne toxoplasmosis—Recent developments.” Experimental Parasitology. 124(1): p. 10-25.

3. 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.

4. 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.

5. 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.

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

7. Dabritz, H.A., et al., “Detection of Toxoplasma gondii-like oocysts in cat feces and estimates of the environmental oocyst burden.” Journal of the American Veterinary Medical Association. 2007. 231(11): p. 1676-1684.

8. Miller, M.A., et al., “Coastal freshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters (Enhydra lutris nereis).” International Journal for Parasitology. 2002. 32(8): p. 997-1006.

9. 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.

10. 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

11. 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.

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

More from Michael Hutchins

In his most recent post, Michael Hutchins (CEO/Executive Director of The Wildlife Society) once again misses the point…


As you might imagine, I was disappointed with your response to my post. It was really just more of the same—a vague defense of the peer-review process, scientific publications, and so forth. Meanwhile, you have yet to dispute a single claim I’ve made in my extensive criticism of the feral cat/TNR literature.

But, like you, I have more important things to do. So, just two brief points:

  1. While I generally agree with your claim that “science is among the most self-correcting of all human endeavors,” I would suggest that this is often in spite of, not because of, its peer-review process.As to the “most severe” consequences for “scientific misbehavior,” I will refer you to Daniel Carlat’s book, Unhinged: The Trouble with Psychiatry—A Doctor’s Revelations about a Profession in Crisis. In it, Carlat reveals that about half the articles written about the antidepressant Zoloft where, at one time, actually ghostwritten by non-physicians working for a marketing firm, and funded by pharmaceutical giant Pfizer (the maker of Zoloft). Prominent psychiatrists were then paid to put their names on the bogus work. These articles were published in prominent peer-reviewed journals, such as the New England Journal of Medicine, the Journal of the American Medical Association, and the American Journal of Psychiatry.

    So, what happened when all of this came to light? “You would think that there would be repercussions,” Carlat told Dave Davies, guest host of NPR’s Fresh Air, during an interview week. “However, there have not been any such repercussions.”

  2. Regarding my alleged portrayal of professional biologists, ecologists and conservationists as cat haters, I have neither stated nor implied anything of the kind. On the contrary, I took you at your word when you wrote, “I have also kept many pets during my lifetime and have bonded with individual animals as diverse as fruit bats, dogs, cats, turtles, frogs, snakes, lizards, and tropical fish.” [1]I’m struck once again by the ease with which you—the trained scientist, as you’re quick to point out—arrive at conclusions with so little consideration of the facts. While I hardly expect you to read my blog regularly, you at least ought to familiarize yourself with the material you’re disputing. If you don’t want to read what I’ve written, that’s fine—but please don’t put words in my mouth.

I suppose I owe you a debt of gratitude, Michael. When, as the CEO/Executive Director of a 9,000-member science organization, you use your bully pulpit to publish a response plagued by exaggerations, misrepresentations, and errors—not to mention its arrogant, dismissive tone—you do a far better job of supporting my position than challenging it.

Literature Cited

1. Hutchins, M., “The Limits of Compassion.” Wildlife Professional (Allen Press). 2007. 1(2): p. 42-44.

Sanctuary In Name Only

Although Vox Felina was launched in April of this year, its origins can be traced back to 2007 and the town of Pahrump, Nevada. There, 748 cats were abandoned in the summer heat—left sick, starving, and dehydrated by the very people who claimed to be their rescuers. Were it not for the heroic efforts of Best Friends Animal Society and a tireless team of volunteers (local and from across the country), nearly all of those cats would have died.

Within the organization operating the Pahrump sanctuary—For the Love Of Cats and Kittens, or FLOCK—there was nothing but finger-pointing. Earlier this year, the case against FLOCK’s former board members was dismissed on a technicality—the result of the case having been badly botched from the outset by the Nye County District Attorney’s Office. Anybody familiar with the story knows of D.A. Robert Beckett’s incompetence and questionable judgment (e.g., in a six-hour period, Beckett once rolled two cars—one of which belonged to the county—resulting in a citation for DUI). Then, last week, The Wall Street Journal reported that Beckett’s under investigation for dipping into County funds.

All of this got me thinking—not of Beckett or the D.A.’s Office, but of FLOCK. The organization is still around (although I’m told the leadership has changed). And a few months ago there were reports—which I have been unable to confirm—that FLOCK might be establishing a new sanctuary, this time in neighboring Clark County.

Another FLOCK sanctuary would be a recipe for disaster, and not just because of that organization’s abysmal record. Many cat sanctuaries are overcrowded, underfunded, and—lacking any kind of contingency plan, as is often the case—prone to collapse. And they can be used to cover up institutional hoarding.

Sanctuaries as Alternatives to TNR?
Cat sanctuaries were among the topics discussed at the American Veterinary Medical Association’s 2004 Animal Welfare Forum, “Management of Abandoned and Feral Cats.” Among those suggesting that sanctuaries are a viable alternative to TNR were Linda Winter, former director of the ABC’s Cats Indoors! program:

“Cat sanctuaries, such as those run by Best Friends in Utah, Rikki’s Refuge in Virginia, the Humane Society of Ocean City in NJ, the CCC in California, the Delaware Humane Association in Delaware, and the Habitat for Cats Sanctuary in Massachusetts, keep cats sheltered, safe, and well fed; provide access to routine veterinary care; protect wildlife; and reduce health risks for cats and people. The ABC strongly supports sanctuaries for stray and feral cats as an alternative to TNR that is more humane to both cats and wildlife.” [1]

Former Chief of the U.S. Army Veterinary Corps, Paul Barrows, was another participant in favor of sanctuaries as an alternative to TNR:

“Whether adopted; placed in a confining sanctuary; judiciously used in research, training, or education; or euthanized, removal and not return seems to be the most responsible course of action.” [3]

David Jessup, Senior Wildlife Veterinarian with the California Department of Fish and Game, also weighed in with his own enthusiastic endorsement:

“Recently, another option has become available: enclosed sanctuaries where cats can live out their lives protected from weather and most injury. Large and well-known cat sanctuaries exist in Delaware, Massachusetts, New Jersey, New Mexico, Virginia, and several places in California. Others are being built and operated by individuals and organizations on small and moderate scales similar to other sanctuaries, as described by Winter. This is happening simply because people sense it is the right thing to do. Hopefully, we can all agree this is one thing that truly serves the welfare of both cats and wildlife.” [2]

However, this is the same article in which Jessup alleges—without so much as a single reference to support him—that there are “60–100 million feral and abandoned cats in the United States.” [2] Clearly, there isn’t nearly enough sanctuary space for the number of cats; in fact, sanctuaries are “another option” for only a tiny fraction of the stray, abandoned, and feral cats out there (even when more accurate estimates are considered).

Indeed, in their contribution to AVMA’s 2004 Animal Welfare Forum, Julie Levy and Cynda Crawford suggest as much: “most sanctuary programs that permanently house feral cats are filled to capacity almost immediately after opening.” [5]

And yet, years later, sanctuaries are still being marketed as alternatives to TNR. The ABC, for example, echoes Winter’s 2004 comments in its brochure “Managed” Cat Colonies: The Wrong Solution to a Tragic Problem, and in its short film Trap, Neuter, and Release: Bad for Cats, Disaster for Birds. In the film, produced last year, Steve Holmer, the ABC’s Director of Public Relations, suggests:

“A better solution is to trap, neuter, and remove feral cats, and then relocate them to enclosed cat sanctuaries or shelters, or to adopt them out to safe and comfortable homes.”

Sanctuaries: The Realities and Impacts
Alley Cat Allies opposes sanctuaries for feral cats, citing as concerns the inherent economic and medical challenges, as well as the overall lack of capacity—factors that too often prove insurmountable:

“A number of sanctuaries are forced to close their doors every year due to insufficient funds or an inability to properly care for the cats in the existing confined space.”

FLOCK was a case study, demonstrating in horrific detail that the sanctuary option—even when it’s available—is not always in the best interest of the cats. As one of my Best Friends contacts who was involved in the FLOCK clean-up effort told me, “I’ve got one of the Pahrump cats… I would rather see that cat back on the streets of Vegas, looking for food in Dumpsters, than be where they were at FLOCK.”

Indeed, the FLOCK story is all too familiar to people involved in such large-scale rescue efforts. Consider some of the more dramatic—and therefore “story-worthy”—incidents in recent years:

  • Voice of the Animals Sanctuary (Blanchard, ID, 2006)
    “Disaster responders from The HSUS, working alongside the Idaho Humane Society, found more than 400 cats, and a number of dogs, goats and chickens. Many were in extremely poor health and had to be euthanized.”

    “The animals were housed in and around nine dilapidated mobile homes on the property, according to published reports. Inside the trailers, investigators found that the walls were soaked in urine and the floors caked with feces and filth. Veterinarian and IHS executive director Dr. Jeff Rosenthal described the cats as all being ‘infested with fleas and ear mites. The majority were also in an emaciated state and suffered with upper respiratory illnesses, chronic diarrhea and abscesses,’ among other ailments.” (source:

  • Tiger Ranch (Tarentum, PA, 2008)
    “All told, 380 living cats and 106 dead ones were discovered during a police raid at Tiger Ranch in Frazer Township, which owner and operator Linda Bruno billed as a pet adoption center and Hospice. Since then, many of the cats have died.”

    “‘It’s a death camp,’ said [Howard] Nelson [director of the Philadelphia-based Pennsylvania SPCA, which orchestrated the raid], speaking by cell phone as he helped gather emaciated and diseased cats crammed into trailers and other outbuildings across the 30-acre property. ‘I see cats that can’t walk, and dead cats in litter boxes and lying by food bowls.’” (source:

  • Cats with No Name (Pine Grove Township, PA, 2009)
    “SPCA volunteer Beth Hall said the condition the 148 cats and 10 other animals were found in was unspeakable. ‘Our opinion is that it was heinous. In my opinion, it was like a kitty concentration camp,’ she said. ‘We just don’t understand.’ Mary Ellen Smith, president of the Steinert SPCA board, said the animals were subjected to ‘obvious cruelty and neglect.’”

    In addition, the couple responsible was “accused of stockpiling donated cat food and reselling some of it at auctions to finance drug binges while leaving dozens of animals to go hungry.” (source:

  • 10th Life Sanctuary (LaBelle, FL, 2009)
    “The final statistics tell a story of success and sadness. The closure of the 10th Life Sanctuary represents one of the largest cat rescues in US history. A total of 110 cats were euthanized in the first days of medical triage due to critical medical illnesses, including 17 that were euthanized immediately following the unannounced inspection. Of the remaining 485 cats, 75 of the ferals were euthanized when new placements could not be found for them. This 15% euthanasia rate for the savable cats is in stark contrast to the vast majority of large-scale feline cruelty impoundments in which mass euthanasia is the most common outcome.” (source: Maddie’s Shelter Medicine Program, University of Florida)

*     *     *

To be clear, I’m not opposed to sanctuaries as such. Indeed, I’m a supporter of Best Friends and Shadow Cats Rescue. What I am opposed to is sanctuaries being oversold—generally to an audience that has no knowledge of such matters—as a viable alternative to TNR. To suggest anything of the sort is, at best, disingenuous. Sanctuaries are no more an alternative to TNR than zoos are to the protection of endangered species.

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

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

3. Barrows, P.L., “Professional, ethical, and legal dilemmas of trap-neuter-release.” Journal of the American Veterinary Medical Association. 2004. 225(9): p. 1365-1369.

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

5. 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.

Science Meets Fiction

Unhinged (book cover)

“The reason that we have a peer review process is to assess the quality and likely validity of scientific data and their interpretation… One goal of the peer review process is to assess an author’s command of the existing literature and whether or not it is being cited selectively to support the author’s views, without critical evaluation of contradictory evidence.” —Michael Hutchins, CEO and Executive Director of The Wildlife Society, May 3rd blog post.

Just a week after my previous post—in which I pointed out some high-profile failures of the peer-review process Hutchins defends—I caught this related interview on NPR’s Fresh Air.

In his book Unhinged: The Trouble with Psychiatry—A Doctor’s Revelations about a Profession in Crisis, Dr. Daniel Carlat reveals that about half the articles written about the antidepressant Zoloft where, at one time, actually ghostwritten by non-physicians working for a marketing firm, and funded by pharmaceutical giant Pfizer (the maker of Zoloft). Prominent psychiatrists were then paid to put their names on the bogus work.

Where was the peer-review process—designed to protect against such practices—in all of this? Once again, it seems, the system failed miserably. According to Carlat:

“…these were in journals such as the New England Journal of Medicine, the Journal of the American Medical Association, the American Journal of Psychiatry, etc. So essentially all the top journals that doctors read were publishing unbeknownst, I’m sure, to the journal editors—ghostwritten articles written by an advertising firm, essentially pushing the benefits of Zoloft, and they were being paid to do this by Pfizer.”

The fact that a major drug manufacturer would attempt such a thing is—sadly—not entirely surprising. The fact that these articles were actually published in a number of prestigious journals, though—that is a surprise.

And it highlights a key point I’ve made numerous times already: publication in well-regarded journals is a guarantee of neither the work’s validity nor the authors’ integrity.

Still, the most unsettling part of the story is its epilogue. A recent study cited by Carlat indicates that 10–20% of articles in such journals are still being ghostwritten. And, although the incident prompted some new policies concerning disclosure, there seems to be no accountability for the people responsible. “You would think that there would be repercussions,” Carlat told Fresh Air guest host Dave Davies. “However, there have not been any such repercussions.”

This, too, sounds familiar. Rather than address the misrepresentations, errors, and biases I pointed out in the Longcore paper, for example, Conservation Biology chose to publish more of the same.

Clearly, the “independent peer-review process” Hutchins refers to in his post is the ideal. Its real-world manifestation, however, varies considerably. Too often, it seems, the emphasis is on peers, at the expense of independence and review.

Out-Sciencing the Scientists

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

Hutchins goes on to write:

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

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

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

Dear Michael,

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

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

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

In your post, you write:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Peter J. Wolf

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

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

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

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

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

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

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

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

9. ABC, Human Attitudes and Behavior Regarding Cats. 1997, American Bird Conservancy: Washington, DC.

10. Clancy, E.A., Moore, A.S., and Bertone, E.R., “Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats.” Journal of the American Veterinary Medical Association. 2003. 222(11): p. 1541-1545.

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

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

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

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

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

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

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

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

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

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

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