Sanctuary In Name Only

19 Jul 2010•In the News, Sanctuaries

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: www.Pet-Abuse.com)

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: www.Pet-Abuse.com)

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: www.Pet-Abuse.com)

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.

The Work Speaks—Part 4: Mean Spirited

4 Jun 2010•Population Estimates, Research Protocol, Threats to Wildlife

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

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

In fact, “the work”—taken as a whole—is neither as rigorous nor as conclusive as Lepczyk et al. suggest. And far too much of it is plagued by exaggeration, misrepresentations, errors, and obvious bias. In Part 3 of this series, I discussed the distinction between compensatory and additive predation. Here, I’ll focus on how feral cat/TNR researchers often misuse averages to characterize skewed distributions, and how that error overestimates the impact of free-roaming cats on wildlife.

Something’s Askew
When a data set is skewed, it is inappropriate to use the mean, or average, as a measure of central tendency. The mean should be used only when the data set can be considered normal—the familiar bell curve. As Woods et al put it:

“the simple average number of animals brought home is not a useful measure of central tendency because of the skewed frequency distribution of the numbers of prey items brought home…” [2]

Studies of cat predation routinely reveal a positively skewed distribution; a few cats are responsible for many kills, while many of the cats kill few, if any, prey. So when researchers use the mean to calculate the total number of prey killed by cats in a particular area, they overestimate the cats’ impact.

How common is this? Very [see, for example, 3-9]. Of the many cat predation studies I’ve read, only a few [2, 10, 11] properly account for the skewed nature of this distribution. And others [12-17] often take these inflated figures at face value—as evidence of the impact cats have on wildlife. Published repeatedly, the erroneous estimates take on an undeserved legitimacy.

The proper method for handling skewed distributions involves data transformations, the details of which I won’t go into here. The important point is this: in the case of a positively skewed distribution, the back-transformed mean will always be less than the simple mean of the same data set.

Big Deal
Depending on the particular distribution, the difference between the simple mean and the back-transformed mean can be considerable. Let’s use the 2003 study by Woods et al. [2] to illustrate. In the case of mammals killed and returned home by pet cats, the back-transformed mean was 28.3% less than the simple mean. Or, put another way, the simple mean would have overestimated the number of mammals killed by 39.5%. Similarly, when all prey items were totaled (as depicted in the illustration above), the simple mean would have overestimated the total number off all prey (mammals, birds, herpetofauna, and “others”) by 46.9%.

On the other hand, the figures for birds appear to break the rule mentioned above. In this case, the back-transformed mean (4.1) is actually a bit higher than the simple mean (4.0). How can this be? In order to log-transform the data set, Woods et al. had to first eliminate all the instances where cats returned home no prey—you can’t take the logarithm of 0. So, they were actually working with two data sets. Now, the second data set—which includes only those cats that returned at least one prey item—is also highly positively skewed. As a point of reference, its simple mean was approximately 5.6 birds/cat, which, compared to the back-transformed mean, is an overestimation of 37.5%.

By now, it should be apparent that log-transformed means have another important advantage over simple means: because you have to eliminate those zeros from the data set, you are forced to focus only on the cats that returned prey home—which, of course, is the whole point of such studies! And in the case of this study, Woods et al. found that 20–30% of cats brought home either no birds or no mammals. And 8.6% of the cats brought home no prey at all over the course of the study.

Transforming a data set (and then back-transforming its mean) is simpler than it sounds, but Barratt offers a useful alternative, rule-of-thumb method (one echoed by Fitzgerald and Turner [18]):

“…median numbers of prey estimated or observed to be caught per year are approximately half the mean values, and are a better representation of the average predation by house cats based on these data.” [10]

So, whereas Dauphiné and Cooper (and others) suggest increasing such estimates by factors of two and three (“predation rates measured through prey returns may represent one half to less than one third of what pet cats actually kill…” [14]), they should, in fact, be reducing them by half.

Cat Ownership
There are other instances in which simple averages are used to describe similarly skewed distributions—with similar results. That is, they overestimate a particular characteristic—and not in the cats’ favor.

Cat ownership, for example, is not a normal distribution. Many people own one or two cats; a few people own many cats. This is precisely what Lepczyk et al. found in their 2003 study:

“The total number of free-ranging cats across all landscapes was 656, ranging from 1 to 30 per landowner…” [6]

In fact, about 113 (I’m estimating from the histogram printed in the report) of those landowners owned just one cat apiece. About 70 of them owned two cats. Only one—maybe two—owned 30 cats. And yet, Lepczyk et al. calculate an average of 2.59 cats/landowner (i.e., 656 cats/253 landowners who allow their cats outdoors), thereby substantially overestimating cat ownership—and, in turn, predation rates (which calculations are based upon the average number of cats/landowner).

Lepczyk et al. are not the only ones to make this mistake; several other researchers have done the same. [4, 5, 7-9]

Outdoor Access
The amount of time cats spend outdoors is also highly positively skewed, as is apparent from the 2003 survey conducted by Clancy, Moore, and Bertone. [19] Their work showed that nearly half of the cats with outdoor access were outside for two or fewer hours a day. And 29% were outdoors for less than an hour each day.

Among those researchers to overlook the skewed nature of this distribution are Kays and DeWan, who calculate an average of 8.35 hours/day. This greatly overestimates potential predation, and leads them to conclude—erroneously—that the actual number of prey killed by cats was “3.3 times greater than the rate estimated from prey brought home,” [9] as was discussed previously.

Compound Errors
Clearly, these errors are substantial—in some cases, doubling the apparent impact of cats on wildlife. Of course the errors are even more significant when one inflated figure is multiplied by another—as when Lepczyk et al. [6] multiply the average number of prey items returned by the average number of outdoor cats per owner. The resulting predation figures may well be four times greater than they should be! (Actually, there are additional problems with the authors’ predation estimates, which I’ll address in a future post).

* * *

The fact that such a fundamental mistake—one a student couldn’t get away with in a basic statistics course—is made so often is shocking. The fact that such errors slip past journal reviewers is inexcusable.

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

2. 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.

3. 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

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

5. 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.

6. 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.

7. Crooks, K.R., et al., “Exploratory Use of Track and Camera Surveys of Mammalian Carnivores in the Peloncillo and Chiricahua Mountains of Southeastern Arizona.” The Southwestern Naturalist. 2009. 53(4): p. 510-517.

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. 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.

10. 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.

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

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

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

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

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

17. Clarke, A.L. and Pacin, T., “Domestic cat “colonies” in natural areas: a growing species threat.” Natural Areas Journal. 2002. 22: p. 154–159.

18. 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.

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

The Work Speaks—Part 1: Lost in Translation

24 May 2010•Cats and Birds, Research Protocol, The Cat Debate, Threats to Wildlife

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

* * *

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The Things People Say (or Don’t)—Part 3

30 Apr 2010•Cats and Birds, In the News, Legal Issues

The American Bird Conservancy (ABC) is among the most visible organizations to oppose TNR—and put PR ahead of the relevant science (which ABC has been doing for years now).

ABC was one (along with the L.A. Audubon Society and Urban Wildlands Group) of several petitioners in the case that eventually led to an injunction against publicly supported TNR in Los Angeles. Following the court’s decision, 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]… It’s conservatively estimated that they kill about 500 million birds a year.

Days later, I sent Holmer an e-mail, asking for details about his figure of 160 million feral cats (the number of birds killed could, I assumed, be addressed later). To his credit—and unlike the people I tried to contact at the Urban Wildlands Group and L.A. Audubon Society—Holmer actually replied, leading to a cordial but brief correspondence in which he directed me to the work of Nico Dauphiné and Robert J. Cooper.

Sure enough, just two pages into Dauphiné and Cooper’s article [1] (available for download via the ABC website):

There is therefore an estimated total of 117–157 million free-ranging cats in the United States.

But there are a number of significant problems with their estimate—which is calculated by combining an estimated number of feral cats with an estimated number of owned cats having outdoor access. Here, in a nutshell, is a breakdown of their calculation:

Dauphiné and Cooper start with 60–100 million “stray and feral (unsocialized) cats, nearly all of which range freely outdoors” a figure taken from a 2004 paper by David Jessup [2]. But, because Jessup didn’t cite his source(s), this is actually no estimate at all. At best, it’s a guess—and one intended to paint as stark a picture as possible.

Then, citing a 2004 paper (which in turn cites a study commissioned by ABC—the results of which are summarized here) by ABC’s Linda Winter [3], Dauphiné and Cooper suggest that “approximately 65%” of pet cats “are free-ranging outdoor cats for at least some portion of the day.” Taking 65% of 88 million—the number of pets cats estimated by the American Pet Products Association’s 2008 National Pet Owners Survey—the authors arrive at 57 million pet cats with outdoor access.

But what does that mean, to be free-ranging for at least some part of the day?

A 2003 survey conducted by Clancy, Moore, and Bertone [4] suggested that nearly half of the cats with outdoor access were outside for two or fewer hours a day. And 29% were outdoors for less than an hour each day. And a closer look at the study commissioned by ABC indicates similar behavior: “35% keep their cats indoors all of the time” and “31% keep them indoors mostly with some outside access.” [5]

For Dauphiné and Cooper, though, these cats are no different from feral cats. For them to simply add the number of “part-time” outdoor cats to the population of “free-ranging outdoor cats” is highly misleading! The authors have no idea what impact these cats might have on bird populations—which is the stated purpose of their paper.

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

* * *

OK, back to Steve Holmer and the L.A. Times…

Holmer’s estimate of 160 million is not a range, but the high limit of a seriously-flawed estimate (which is itself based on little more than wild guesses). And he refers specifically to feral cats—an error even Jessup, Dauphiné, and Cooper (none of whom, it seems, is likely to give feral cats even the slightest benefit of the doubt) don’t make.

Given the context of the discussion—TNR in Los Angeles—such an error was likely (perhaps intended?) to have serious consequences. To suggest that there are 160 million feral cats in this country—approximately one feral cat for every two human inhabitants—is irresponsible and manipulative. And it raises doubts about the integrity of ABC and its representatives. All of which I told Holmer. His reply read, in part:

We are doing are [sic] best to convey the facts as they become available. The 160 million figure was based on an earlier version of Nico’s latest paper and are now being updated in our materials which should now say:

There are currently 88 million pet cats in the U.S. according to a pet trade association, and that number is growing. In addition, it is estimated that there may be 60–100 million free-ranging feral cats in the U.S., and that these cats may collectively kill more than one million birds each day. Reducing this mortality even a small amount could potentially save millions of birds each year.

I haven’t checked the ABC website to verify Holmer’s claim. In any event, the damage was already done; ABC and the other petitioners had put a stop to publicly supported TNR in Los Angeles. And, from what I’ve seen (I’ve yet to wade through the thousands of pages of discovery documents in the case), they’d done so by selectively overlooking, ignoring, and misrepresenting the scientific research. Or, in the case of Holmer’s comment to the Times, simply “inventing” it.

By the way, I asked Holmer about his revised figure of “more than one million birds each day” killed by cats. He’s stopped replying to my e-mail.

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

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

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

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

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