National Feral Cat Day 2011

National Feral Cat Day 2011 posterAs many of you are no doubt aware, Sunday is National Feral Cat Day, a holiday created 10 years ago by Alley Cat Allies “to raise awareness about feral cats, promote Trap-Neuter-Return, and recognize the millions of compassionate Americans who care for them.” This year, there are more than 320 events planned across all 50 states.

Even so, I’ll bet there are a number of scientists, journalists, and others who—despite devoting a great deal of attention to the topic the rest of the year—have allowed the holiday to sneak up on them, and therefore haven’t made plans. Here, then, are some suggestions for how some of these folks (listed in no particular order) might mark the 10th annual National Feral Cat Day.

•     •     •

Thank you to all those who—whether one day a year or year-round—raise awareness about, and care for, abandoned, stray, and feral cats, and promote TNR.

Demanding (a) Better Service

U.S. Fish and Wildlife Service under fire for proposed roundups of free-roaming cats in the Florida Keys, an out-of-control burn on National Key Deer Refuge land, and participation in anti-TNR workshop.

Many U.S. Fish and Wildlife Service personnel are, I suspect, looking forward to October—or at least putting September behind them. For those involved with USFWS’s “war on cats,” this month’s been a tough one: too much of the wrong kind of attention.

Camera (en)Trap(ment) Project
September got off to a rocky start with readers (myself included) responding to news of camera traps being used in Florida’s National Key Deer Refuge “to document the number of cats stalking prey in the refuge.”

According to Key West Citizen reporter Timothy O’Hara, cats appeared on 5 percent of the “nearly 7,000 [photos] snapped so far,” whereas the endangered Lower Keys Marsh Rabbit appeared on just 3 percent. (Deer and raccoons topped the list, though specific percentages weren’t mentioned.)

Future plans include “a more in-depth study to get a better handle on the number of cats,” which, says USFWS biologist Chad Anderson, who was interviewed for the story, “will give us better insight into the predator management plan [of which I’ve been highly critical]. We want it to be as effective and efficient as possible.”

Five days later, Big Pine Key resident Jerry Dykhuisen took USFWS to task in a letter to the editor calling O’Hara’s article “our quarterly puff piece about how great it’s all going to be when feral cats are trapped and removed from Big Pine Key.” Dykhuisen, vice president of Forgotten Felines, pointed out the incredible expense associated with the proposed roundup (a “government boondoggle that is nothing more than a waste of our tax dollars and job security for U.S. Fish and Wildlife”) and the risk of skyrocketing rodent populations if eradication efforts were actually “successful,” and challenges the “‘best available science’ of which they are so proud” (which “is not really very good science at all, being decades old, using statistical methods that are highly suspect, and not even being conducted on Big Pine.”).

Tax dollars are at a premium in this economy,” wrote Dykhuisen, “and the idea of spending more than $10,000 per cat on a project that has no chance of success is mindless government at its worst.”

The following week, a letter to the editor from Forgotten Felines volunteer Valerie Eikenberg called the camera trap project a lame-brain experiment,” criticizing Refuge personnel for baiting the cameras with cat food. “Why spend thousands of taxpayer dollars to figure out a question that any second-grader could answer,” she asked.

Refuge Manager Anne Morkill disputes Eikenberg’s claim: “extremely small amounts of bait were used at only two camera trap sites located at unauthorized cat feeding stations, where the cats were already lured by food. The purpose was to get the animals to stop and pause for a clear photo for identification purposes.” (I received a similar explanation by e-mail from Anderson.)

Note: I’ve tried to contact O’Hara, who badly misrepresented the science in his story (for example: “Research indicates that cat predation accounts for 50 percent to 77 percent of the deaths of Lower Keys marsh rabbits and Key Largo woodrats.”), but he’s not responded to my e-mail requests.

(Mis)prescribed Burn
Just two weeks later, Refuge personnel once again found themselves defending their actions, this time for a prescribed burn that grew quickly out of control, scorching about 100 acres—five times what was originally planned.

For some, at least, this was the last straw. “Morkill has to go!” read one particularly harsh comment to a Key West Citizen story about the fire.

“Not tomorrow, not next week, not at the end of the fiscal year, NOW!! She is completely over her head and needs to transfer somewhere else. From the complete mishandling of the feral cat situation [to] the out of controlled prescribed burn that threatened both residents AND sensitive wildlife… Ms. Morkill is a complete and total failure at her position. What a travesty. Go back to wherever you came from Anne, you’re a failed experiment in the Keys.”

Earlier this week, USFWS officials met with residents to explain the results of an internal investigation into the fire.

According to USFWS Fire Ecologist Vince Carver, “The review team came up with three findings: One, it was too dry to burn. Two, the [fire] crew that did it, the majority of them did not have enough experience for this type of burn. And three, after they did screw up, they did a fantastic job.” [1]

Refuge fire management specialist Dana Cohen “repeatedly apologized to residents, saying, ‘We made a bad call’ in deciding to burn, but most appeared unmoved.” [1] The “unhappy audience,” as Citizen reporter Adam Linhardt describes them, were short on patience, “speaking out and lambasting” USFWS officials. “One person described the burn as a ‘fiasco’ and called for Cohen’s firing.” [1]

National Feral Cat Policy
A day after the blaze on Big Pine Key, USFWS was trying to tamp down another fire of its own making. This one, too, had gotten out of hand—but on a national scale.

In a post on its Open Spaces blog, USFWS responded to “many expressions of interest and concern regarding participation by U.S. Fish and Wildlife Service employees at an upcoming Wildlife Society conference.” This, of course, is a reference to Informing Local Scale Feral Cat Trap-Neuter-Release Decisions, the day-long workshop being presented by Tom Will, Mike Green (both of USFWS), and Christopher Lepczyk (University of Hawaii).

As part of that conference, two Service biologists are presenting a workshop designed to help wildlife biologists and other conservationists effectively communicate the best available science on the effects on wildlife from free-ranging domestic cats. The Service has no national policy concerning trap-neuter-release programs or feral cats.

If there’s no official policy, it’s not for lack of effort.

In his 2010 presentation to the Bird Conservation Alliance, What Can Federal Agencies Do? Policy Options to Address Cat Impacts to Birds and Their Habitats, Will is pushing for a “Firm policy statement—clear, definitive, easily available—as a tool for partners.” In fact, it looks like he’s suggesting that such a policy already exists, citing, for example, a 2007 “response to inquiry” from the USFWS Charleston Field Office:

Is it still FWS policy to promote legislation banning feeding of wildlife? Yes. The U.S. Fish and Wildlife Service (Service) stands firmly behind its recommendations promoting legislation banning the feeding of wildlife, especially nuisance species such as feral cats. Local governments are better equipped than are Federal and State agencies to regulate feral and free-ranging cats since most local governments have ordinances in place to address domestic animal issues as well as animal control services and personnel to implement those ordinances.

Is it still FWS policy opposing free ranging cats and establishment of feral cat colonies? Yes. The Service continues to oppose the establishment of feral cat colonies as well as the perpetuation and continued operation of feral cat colonies. As an agency responsible for administering the regulatory provisions of the Endangered Species Act (ESA) and the Migratory Bird Treaty Act (MBTA), the Service’s position is that those practicing Trap-Neuter-Release (TNR) could be subject to prosecution under those laws.

Is it still FWS policy opposing TNR programs? Yes… the Service’s New Jersey Field Office correctly states that “a municipality that carries out, authorizes, or encourages others to engage in an activity that is likely to result in take of federally protected species, such as the establishment or maintenance of a managed TNR cat colony, may be held responsible for violations of Section 9 of the ESA.”

Will goes on to cite several more passages from the letter quoted above, sent in November 2009 from the New Jersey Field Office to the New Jersey Department of Environmental Protection Division of Fish and Wildlife “in support of the New Jersey Fish and Game Council’s Resolution on Trap-Neuter-Release (TNR) and free-ranging domestic cats, passed June 19, 2007.”

The Service strongly opposes domestic or feral cats (Felis catus) being allowed to roam freely within the U.S. due to the adverse impacts of these non-native predators on federally listed threatened and endangered (T&E) species, migratory birds, and other vulnerable native wildlife. Therefore, the Service opposes TNR programs that allow return of domestic or feral cats to free-ranging conditions.

Migratory birds are Federal trust resources and are afforded protection under the MBTA, which prohibits the take of a migratory bird’s parts, nest, or eggs. Many species of migratory birds, wading birds, and songbirds nest or migrate throughout New Jersey. Migratory birds could be subject to predation from State municipality, or land manager-authorized cat colonies and free-ranging feral or pet cats. Predation on migratory birds by cats is likely to cause destruction of nests or eggs, or death or injury to migratory birds or their young, thereby resulting in a violation of the MBTA.

All of which looks a lot like a “national policy concerning trap-neuter-release programs or feral cats.” Which might explain why the American Bird Conservancy has the NJ Field Office letter posted on its website (PDF). (ABC and TWS were among the signatories to a letter sent earlier this year to Department of Interior Secretary Ken Salazar, “urg[ing] the development of a Department-wide policy opposing Trap-Neuter-Release and the outdoor feeding of cats as a feral cat management option, coupled with a plan of action to address existing infestations affecting lands managed by the Department of the Interior.”)

To hear USFWS tell it, Will and Green don’t even speak for USFWS.

In order to protect the independence and integrity of their work and the quality of the scientific information generated, the Service does not review or edit their work based on its potential policy implications. Any findings or conclusions presented at this workshop, as well as other scientific papers and presentations by Service employees, are those of the organizers and do not necessarily represent those of the Fish and Wildlife Service.

How exactly does that work? Are taxpayers (who are, like it or not, supporting TWS’s conference: “the Service is a sponsor of the conference as a whole”) expected to believe that Informing Local Scale Feral Cat Trap-Neuter-Release Decisions wasn’t put together “on company time,” using agency resources? Like me, commenter “Mrs. McKenna” isn’t buying it:

“I find it very strange that there would be not be an edit or review of the presentations done by employees/consultants (personnel on your payroll.) Quite frankly, I know of no organization that would allow taxpayer paid employees to present at a conference of this magnitude without a screening of materials to be presented. In fact, one could deem this type of policy quite irresponsible… If there were no interest in presenting a specific viewpoint supported by U.S. Fish & Wildlife for current or upcoming policies, one can be quite certain no such presentation would be sponsored.”

Mrs. McKenna and I are, it turns out, not the only skeptics. At last check, there were 50 comments on the USFWS post (not all of them critical of the Service, of course), a record for the Open Space blog (which, since its inception in late April, has attracted just 140 comments across 97 posts—including the August 2 post about “a recent incident where the Service inadvertently issued a citation in Fredericksburg, Virginia,” which attracted 46 comments).

Uncommitted
Although USFWS is, according to its Office of External Affairs, “committed to using sound science in its decision-making and to providing the American public with information of the highest quality possible,” recent events suggest otherwise.

Actually, past events tell a similar story.

In its Migratory Bird Mortality fact sheet (PDF), published in January 2002, USFWS offers this prediction: “Many citizens would be surprised to learn that domestic and feral cats may kill hundreds of millions of songbirds and other avian species each year.”

“A recent study in Wisconsin estimated that in that state alone, domestic rural cats kill roughly 39 million birds annually. Add the deaths caused by feral cats, or domestic cats in urban and suburban areas, and this mortality figure would be much higher.” [2]

In this case, the Service’s “best available science” can be traced to the infamous Wisconsin Study, [3] and—eventually—to “a single free-ranging Siamese cat” that frequented a rural residential property in New Kent County, Virginia. [4])

Nearly 10 later, Migratory Bird Mortality is still available from the USFWS website. So much for “using sound science in its decision-making and to providing the American public with information of the highest quality possible.”

USFWS is right about one thing, though: many citizens are surprised—just not in the way the Service imagined. The public, to whom USFWS is ostensibly accountable, is surprised at the way their tax dollars are being used to fund a witch-hunt. And, judging by the overwhelming response to the USFWS/TWS workshop (see, for example, Best Friends Animal Society’s Action Alert, blog posts from Alley Cat Rescue and BFAS co-founder Francis Battista, and the Care2 petition), the public has had enough.

With access to both information and “broadcast” technology more accessible than ever, it’s becoming increasingly difficult for USFWS to continue with business as usual. The people the Service is supposed to—well, serve—are demanding better science, more transparency, and greater accountability. People are paying attention like never before.

Think of it as “the new normal.”

Literature Cited
1. Linhardt, A. (2011, September 29). Residents rage about rogue fire—Fed officials apologize: ‘We made a bad call’. The Key West Citizen, p. 1A,

2. n.a., Migratory Bird Mortality. 2002, U.S. Fish and Wildlife Service: Arlington, VA. www.fws.gov/birds/mortality-fact-sheet.pdf

3. 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

4. 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

More Cats, Less Brain Cancer

“Evidence continues to pile up,” writes Michael Hutchins, Executive Director and CEO of The Wildlife Society, in yesterday’s blog post, “that Toxoplasmosis, a disease caused by a parasite (Toxoplasma gondii) that lives in the guts of cats, may be responsible for serious human health problems.”

Hutchins was referring to a recent study in which researchers found “Infection with T. gondii was associated with a 1.8-fold increase in the risk of brain cancers across the range of T. gondii prevalence in our dataset (4–67 percent).” [1]

True to form, Hutchins used the opportunity to call for “doing away with managed cat colonies and TNR (trap-neuter-release) management practices for feral cats,” making a public plea to “public health officials, including the CDC.”

But what exactly does this latest study contribute to Hutchins’ “pile of evidence”?

The Study
According to a news release from the U.S. Geological Survey, “the study analyzed 37 countries for several population factors” and “showed that countries where Toxoplasma gondii is common also had higher incidences of adult brain cancers than in those countries where the organism is not common.”

“The study does not prove that Toxoplasma gondii directly causes cancer in humans, and the study does not imply that an infected person automatically has high cancer risk,” says [Kevin] Lafferty, who is based at the USGS Western Ecological Research Center. “However, we do know that Toxoplasma gondii behaves in ways that could stimulate cells towards cancerous states, so the discovery of this correlation offers a new hypothesis for an infectious link to cancer.”

According to the study’s abstract (I’ve been unable to access the paper), the authors took into account several factors:

“We corrected reports of incidence for national gross domestic product because wealth probably increases the ability to detect cancer. We also included gender, cell phone use and latitude as variables in our initial models. Prevalence of T. gondii explained 19 per cent of the residual variance in brain cancer incidence after controlling for the positive effects of gross domestic product and latitude among nations.” [1]

It will be interesting to compare—once I’m able to review the study in detail—these findings with those published earlier this year in the Journal of the National Cancer Institute (a collaborative effort involving several agencies, including, as it happens, the CDC):

“The relatively low variation in incidence and death rates for cancer of the brain and [other nervous system] nationally and internationally suggests that environmental risk factors do not play a major role in this disease. In fact, other than hereditary tumor syndromes and increased familial risk without a known syndrome, the only known modifiable causal risk factor for brain tumors is exposure to ionizing radiation.” [2, in-line citations removed for readability]

Correlation ≠ Causation
To illustrate the critical difference between correlation and causation, author Charles Seife uses the dramatic example of the mid-1990s NutraSweet scare—which, incredibly, was also linked brain cancer (falsely, as it turns out).

“Lots of people… don’t eat foods that contain the artificial sweetener NutraSweet for fear of developing brain cancer,” writes Seife, tracing the mythical connection to “a bunch of psychiatrists led by Washington University’s John Olney.”

“These scientists noticed that there was an alarming rise in brain tumor rates about three or four years after NutraSweet was introduced in the market.

Aha! The psychiatrists quickly came to the obvious conclusion: NutraSweet is causing brain cancer! They published their findings in a peer-reviewed journal, the Journal of Neuropathology and Experimental Neurology, and their paper immediately grabbed headlines around the world.

But a closer look at the data shows how unconvincing the link really is. Sure, NutraSweet consumption was going up at the same time brain tumor rates were, but a lot of other things were on the rise, too, such as cable TV, Sony Walkmen, Tom Cruise’s career. When Ronald Reagan took office in 1981, government spending increased just as dramatically as brain tumor rates… The correlation between government overspending and brain cancer is just as solid as the link between NutraSweet and brain cancer.” [3]

Sounds eerily familiar, doesn’t it?

Given the numerous factors and interrelationships involved in developing brain cancer—some of which, of course, we don’t even know—Hutchins’ eager indictment of cats is, at the very least, premature. In fact, Hutchins is going to have a difficult time connecting the dots in light of recent research.

More Cats, Less Brain Cancer
If brain cancer is more common where T. gondii is more common, then one might expect rates of brain cancer to increase over time as the prevalence of T. gondii increases. Which would seem to be the case here in the U.S., if cats are indeed the culprit.

According to data compiled last year in Conservation Biology, the population of pet cats tripled over the past 40 years, from approximately 31 million in 1971 to more than 90 million today. [4]

So what about brain cancer?

In 2006, researchers using data from the Surveillance, Epidemiology, and End Results Program for 1973–2001 were surprised to find incident rates decreasing. Following an increase of 1.68 percent between 1973 and 1987, the incident rate began to drop off by 0.44 percent annually (as indicated in the chart below; EAPC = estimated annual percentage of change).

“The cause for this decline,” suggest the study’s authors, “is unclear because of the paucity of definitive knowledge on the risk factors of brain cancer, but solace can be taken from the fact that brain cancers are not rising in this era of increasing environmental toxic exposures.” [5]

More recently, a report published by the Central Brain Tumor Registry of the United States (PDF) found “no statistically significant trend in incidence rates of all primary brain tumors from 2004 through 2007.” [6]

•     •     •

Lafferty and his colleagues concede that their work is “correlational,” a jumping-off point for further investigation. Again, I haven’t been able to read the paper yet, but I’m skeptical that their line of inquiry is headed anywhere productive. Cast a net as wide as they did—surveying the prevalence of T. gondii and incidence of brain cancer across 37 countries—and you’re bound to catch something.

Of course, something is all Michael Hutchins needs for his witch-hunt.

Hutchins refers to piles of evidence without taking the trouble to examine any of it, simply ignoring what doesn’t fit neatly into his narrative—declining brain cancer rates in the U.S., for example. Or, some rather interesting comments from Lafferty himself (which, strangely, were omitted from USGS’s news release, but were mentioned by several other news outlets, including LiveScience and Fox News):

“…one shouldn’t be panicking about owning cats… The risk factors for getting Toxoplasma are really hygiene and eating undercooked meat. One should be more concerned about those than pets.”

That sounds familiar, too. It’s the same advice the CDC provides on its Website.

Literature Cited
1. Thomas, F., et al., “Incidence of adult brain cancers is higher in countries where the protozoan parasite Toxoplasma gondii is common.” Biology Letters. 2011.

2. Kohler, B.A., et al., “Annual Report to the Nation on the Status of Cancer, 1975, Featuring Tumors of the Brain and Other Nervous System.” Journal of the National Cancer Institute. 2011. http://jnci.oxfordjournals.org/content/early/2011/03/31/jnci.djr077.abstract

3. Seife, C., Proofiness: The Dark Arts of Mathematical Deception. 2010: Viking Adult.

4. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627–629. www.abcbirds.org/abcprograms/policy/cats/pdf/Lepczyk-2010-Conservation%2520Biology.pdf

5. Deorah, S., et al., “Trends in brain cancer incidence and survival in the United States: Surveillance, Epidemiology, and End Results Program, 1973 to 2001.” Neurological Focus. 2006. 20(April): p. E1. thejns.org/doi/pdf/10.3171/foc.2006.20.4.E1

6. n.a., CBTRUS Statistical Report: Primary Brain and Central Nervous System Tumors Diagnosed in the United States in 2004-2007. 2011, Central Brain Tumor Registry of the United States: Hinsdale, IL. www.cbtrus.org/2011-NPCR-SEER/WEB-0407-Report-3-3-2011.pdf

MoJo Losing Its Mojo

Mother Jones, according to its Website, “is a nonprofit news organization that specializes in investigative, political, and social justice reporting.”

“…smart, fearless journalism” keeps people informed—“informed” being pretty much indispensable to a democracy that actually works. Because we’ve been ahead of the curve time and again. Because this is journalism not funded by or beholden to corporations. Because we bust bullshit and get results. Because we’re expanding our investigative coverage while the rest of the media are contracting. Because you can count on us to take no prisoners, cleave to no dogma, and tell it like it is. Plus we’re pretty damn fun.

Right up my alley. Until now.

With “Faster, Pussycat! Kill! Kill!,” published in the July/August issue, articles editor Kiera Butler fails rather magnificently all the way around.

(The article isn’t available directly from MotherJones.com yet, but you can read it (print it, too) simply by signing up for the magazine’s e-mail updates. Enter your e-mail address and click “Sign Up.” In the next window, click on “ACCESS THE ISSUE NOW”—the full issue will then open automatically in Zinio, a digital magazine reader. “Faster, Pussycat! Kill! Kill!” begins on p. 72.)

Cover Art: "Faster, Pussycat! Kill! Kill!"

The title, by the way, comes from a 1965 cult classic in which “Three strippers seeking thrills encounter a young couple in the desert.” Sadly, the film is a better reflection of reality than the information in Butler’s article is.

Population of Cats
The most obvious blunder: Citing what seems to be the same data set (“the US feline population has tripled over the last four decades”) I referred to in my “Spoiler Alert” post, Butler arrives not at 90 million or so, as indicated in the original source [1], or even the bogus 150 million figure the U.S. Fish and Wildlife Service’s Tom Will tried to sell last year to the Bird Conservation Alliance.

No—according to Butler, there were 600 million cats in this country in 2007.

At that time, the human population was 301.3 million. For the sake of easy math, then, let’s call it two cats for every human (talk about “hip-deep in cats”!). This, I believe, sets a new record for absurd population claims—far surpassing the previous record held by Steve Holmer, senior policy advisor for the American Bird Conservancy.

And from here, it only gets worse. While her grossly inflated population figure might be attributed a simple mistake. These things happen (though, of course, one expects such things to be caught by somebody on the editorial staff). However, the misinformation, misrepresentations, and missteps that make up the bulk of “Faster, Pussycat!” betray either willful ignorance or glaring bias. Or both.

Smart, fearless journalism it is not.

One Billion Birds
Butler’s litany of complaints against feral cats is all too familiar: wildlife impacts (birds, in particular), public health threats, the “failures” of TNR, the powerful feral cat lobby, and the emotional/irrational nature of feral cat advocates (i.e., the classic “crazy cat lady” label). Her sources, too, include all the usual suspects; though few are cited, many others are obvious.

Sources of Mortality
Butler claims that domestic cats (“officially considered an invasive species”) top the list of mortality sources, killing perhaps one billion birds annually in the U.S. (Her tabulated comparison of seven mortality sources bears the familiar title “Apocalypse Meow.”)

The source of Butler’s “highest reliable estimates” is the U.S. Fish and Wildlife Service, though the one-billion-birds claim has been made by others, including Nico Dauphine and Robert Cooper, [2, 3] and Rich Stallcup. [4] (In fact, Dauphine refers specifically to Stallcup’s wild-ass guess back-of-the-envelope calculation in her infamous “Apocalypse Meow” presentation.)

Yet even ABC, never one to go easy on cats—or to let science get in the way of their message—ranks building collisions ahead of cats. (Interestingly, neither USFWS nor ABC mentions the most direct human-caused source of bird mortality—hunting—which may account for 120 million avian deaths annually in the U.S. [5])

The one-billion-birds claim hinges upon an inflated estimate of outdoor cats (Dauphine and Cooper, for example, ignore published survey results [6–8], in effect doubling the number of pet cats allowed outdoors) and inflated predation rates (typically extrapolated from small, flawed studies). Multiplying one by the other, the result is impressive (hence, it’s “stickiness”).

Unfortunately, it’s also meaningless.

Still, such aggregate figures are useful for providing a scientific veneer to what is, at its core, little more than a witch-hunt. All of which makes it an easier sell to the media and the general public.

But sound bites ignore the importance of context. Aggregate predation rates, for example, fail to differentiate across vastly different habitats (e.g., islands, forests, coastlines, etc.), species (e.g., songbirds, seabirds, etc.), conditions (e.g., sick and healthy, young and old, etc.), and levels of vulnerability (e.g., ground-nesting and cavity-nesting species, rare and common species, etc.).

Predators—cats included—catch what’s easy. Indeed, at least two studies [9, 10] have found that cat-killed birds tend to be less healthy than those killed in non-predatory events (e.g., the other six mortality sources shown in Butler’s table).

Island Extinctions
In asserting that cats are “responsible for at least 33 avian extinctions worldwide,” Butler overlooks or ignores a critical detail: those extinctions involve primarily—perhaps exclusively—island species, with “insular endemic landbirds [being] most frequently driven to extinction” [11] And even this point is a matter of some debate. “Birds (both landbirds and seabirds) have been affected most by the introduction of cats to islands,” writes Mike Fitzgerald, one of the world’s foremost experts on the subject, “but the impact is rarely well documented.” [12]

“In many cases the bird populations were not well described before the cats were established and the possible role of other factors in changes in the bird populations are treated inadequately.” [12]

So what’s the impact of cats on continents?

In 2000, Fitzgerald and co-author Dennis Turner published a review of 61 predation studies, concluding unambiguously: “there are few, if any studies apart from island ones that actually demonstrate that cats have reduced bird populations.” [13]

Catbird Mortalities
Referring to research conducted by the Smithsonian Migratory Bird Center’s Peter Marra, Butler contends that “cats caused 79 percent of deaths of juvenile catbirds in the suburbs of Washington, DC.” In fact, Marra and his colleagues documented just six deaths attributable to cats, of 42 overall (then justified another three on dubious grounds). [14]

That 79 percent figure comes from dividing the number of deaths attributed to all sources of predation (33) by the total number of deaths documented over the course of the study (42). Butler’s misreading overstates predation by cats by more than 500 percent.

Public Health Threats
“Feral cats,” writes Butler, “can carry some heinous people diseases, including rabies, hookworm, and toxoplasmosis, and infection known to cause miscarriages and birth defects.” Her omission of infection rates—remarkably low in light of the frequent contact between humans and cats—suggests an interest more in fear-mongering than anything else.

Hookworms
A hookworm outbreak in the Miami Beach area in late 2010 made headlines, prompting officials to create a “cat poop map” (cats can pass hookworm eggs in their feces).

Meanwhile, Floridians were dying of influenza or pneumonia by the hundreds. In fact, according to the Florida Department of Health, 100–140 or so die each week during the winter months. (Actually, that figure accounts for only 24 of the state’s 67 counties, so the total is likely much higher.)

My point is not to dismiss the risk of “heinous people diseases” (or the suffering of those who become infected) but to put that risk into perspective. (In terms of public health, we’re better off focusing on frequent hand washing, sneezing into our sleeves, and, in the case of hookworms on the beach, wearing flip-flops—as opposed to, say, exterminating this country’s most popular companion animal by the millions.)

Toxoplasmosis
According to the Centers for Disease Control and Prevention’s Website, “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.”

(The same is true of feeding feral cats, by the way. While it’s true that their infection rates tend to be higher, [15] our frequent, close contact with pet cats more than offsets these differences.)

TNR
“In theory,” writes Butler, “TNR sounds great. If cats can’t reproduce, their population will decline gradually. Unfortunately, it doesn’t work. To put a dent in the total number of cats, at least 71 percent of them must be fixed, and they are notoriously hard to catch.”

In Los Angeles, adds Butler, “it failed miserably in the past.”

Contrary to Butler’s claims, however, there are numerous well-documented examples of TNR programs reducing colony size.

Perhaps the best-known TNR success story in this country is ORCAT. As of 2004, ORCAT, run by the Ocean Reef Community Association, had reduced its “overall population from approximately 2,000 cats to 500 cats.” [16] According to the ORCAT Website, the population today is approximately 350, of which only about 250 are free-roaming.

Other examples include a TNR program on the campus of the University of Florida University of Central Florida,
Orlando, in which caretakers found homes for more than 47 percent of the campus’ socialized cats and kittens, helping them reduce the campus cat population more than 66 percent, from 68 to 23. [17]

In North Carolina, researchers observed a 36 percent average decrease among six sterilized colonies in the first two years (even in the absence of adoptions), while three unsterilized colonies experienced an average 47 percent increase. [18] Four- and seven-year follow-up censuses revealed further reductions among sterilized colonies. [19]

A survey of caretakers in Rome revealed a 22 percent decrease overall in the number of cats through TNR, despite a 21 percent rate of “cat immigration.” [20]

And in South Africa, researchers recommended that “a suitable and ongoing sterilization programme, which is run in conjunction with a feral cat feeding programme, needs to be implemented” [21] on the campus of the University of KwaZulu-Natal’s Howard College—despite its proximity to “conservation-sensitive natural bush habitat and a nature reserve on the northern border.” [22]

The Cost of TNR
“Cash-strapped cities,” argues Butler, “can’t afford to chase down, trap, and sterilize every stray—a process that costs $100 per kitty.” So, can these cities afford to round up and kill the cats?

Mark Kumpf, past president of the National Animal Control Association doesn’t think so. “There’s no department that I’m aware of,” says Kumpf, “that has enough money in their budget to simply practice the old capture-and-euthanize policy; nature just keeps having more kittens.” Traditional control methods, he says, are akin to “bailing the ocean with a thimble.” [23]

The Cat Lobby
If TNR is so ineffective, why is it becoming the feral cat management approach of choice across the country (adopted in “at least 10 major cities,” according to Butler)? It must be the powerful cat lobby.

Alley Cat Allies, “whose budget was $5.3 million last year,” writes Butler, “has enjoyed generous grants from cat-food venders like PetSmart and Petco.”

It’s a play straight out of Dauphine’s playbook: paint the avian-industrial complex TNR opponents as victims of the powerful cat lobby. (In The Wildlife Professional’s recent special issue, “The Impact of Free Ranging Cats,” Dauphine complains: “The 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])

Alley Cat Allies
How generous were these grants, exactly? According to ACA’s 2010 Annual Report (PDF):

“Alley Cat Allies received more than $5.2 million in support between August 1, 2009 and July 31, 2010: more than 69,000 individuals contributed $4.8 million, including over $1 million in bequests. An additional $245,000 came from Workplace Campaigns, and over $14,000 came from foundation grants.”

Roughly 0.2 percent of their “total public support” came from all foundations combined. In 2009, grants and foundations accounted for 1.7 percent; in 2008, 1.0 percent.  (Maybe Butler never got the memo re: MoJo’s commitment to bullshit-busting.)

New Jersey Audubon
Another of Dauphine’s complaints that found its way into “Faster, Pussycat!”:

“Pro-feral groups—there are 250 or so in the United States—have used their financial might to woo wildlife groups. Audubon’s New Jersey chapter backed off on its opposition to TNR in 2005, around the same time major foundations gave the chapter grants to partner with pro-TNR groups.”

What Butler (like Dauphine before her) fails to acknowledge is the important role NJAS plays in the New Jersey Feral Cat & Wildlife Coalition, which has developed a set of model protocols and ordinances designed to help municipal TNR programs in ensuring the protection of any vulnerable native wildlife (DOC).

This is exactly the kind of collaborative effort that should be supported.

For what it’s worth: it’s not clear that NJAS was easily wooed with grant funding. A quick visit to Guidestar.com reveals that NJAS brought in $6.8 million in 2008, and had $25.6 million in “net assets or fund balances” on its books. (I’ve been unable to determine the amount of grant funding NJAS received for “this important initiative,” as CEO and VP of Conservation and Stewardship Eric Stiles described it in a 2008 newsletter. [25])

Mental Health
Butler frames the TNR debate using what’s come to be standard form: rationale scientists on one side; on the other, cat advocates fueled by emotion. And mental illness, too, apparently: “There’s also speculation that [toxoplasmosis] can trigger schizophrenia and even the desire to be around cats—some researchers blame the crazy-cat-lady phenomenon on toxo.”

A Heated Debate
It’s a dangerous combination, according to Butler.

“Many of the biologists I spoke with say they’ve been harassed and even physically threatened when they’ve presented research about the effect cats have on wildlife.”

Is it really so one-sided?

Why didn’t Butler mention the case of Jim Stevenson, the Galveston birder who, in 2006, shot and killed (though not immediately) a feral cat within earshot of the cat’s caretaker? [26]

Or, more recently, the charges of attempted animal cruelty filed by the Washington Humane Society against Dauphine? (Or, for that matter, the stream of toxic comments almost guaranteed to accompany nearly any online story about feral cats or TNR.)

Clearly, the “cat people” don’t have a monopoly on emotional—even violent—responses to the issue.

Sustaining a Killer
When Butler tells an ecologist she knows that she’s feeding a feral cat, she’s told: “Basically, you’re sustaining a killer.” Which is essentially Butler’s intended take-away:

“Until they do [invent a single-dose sterilization drug], biologists recommend a combination of strategies. For starters, quit feeding ferals: Beyond sustaining strays, the practice often leads to delinquent pet owners to abandon their cats outdoors, assuming they will be well cared for.”

Are we to believe that abandonment is reduced or eliminated where the feeding of feral cats is prohibited? Owners (delinquent, I agree) interested in dumping their cats can, unfortunately, do so easily.

The far greater incentive for dumping comes from local shelters, most of which euthanize kill the majority of cats brought in. Many require a surrender fee.

I’m just about the last person to defend the dumping of cats, but shouldn’t we acknowledge the aspects of “animal control” policy that contribute to it?

But back to this idea that “no food” means “no ferals.” It sounds reasonable enough, but doesn’t hold up very well to scrutiny. For one thing, where there are humans, there’s food to be found. In fact, even where there are no people, cats don’t starve.

On Marion Island—barren and uninhabited—it took 19 years to eradicate approximately 2,200 cats. Their only human provision: “the carcasses of 12,000 day-old chickens” each injected with the poison sodium monofluoroacetate. [27] (The rest—the vast majority—were killed through the introduction of feline distemper, intensive hunting and trapping, and dogs. [28, 27])

Is Butler suggesting that the cats in her neighborhood would have it tougher than the Marion Island cats? Even setting aside the cruelty involved, we’re not likely to starve our way out of the “feral cat problem.” Unlike TNR, such an approach only drives the cats (and their caretakers) underground.

This, of course, is roughly the same approach that’s proved ineffective failed so spectacularly at addressing so many other complex issues, including drug enforcement, immigration policy, gays in the military, and so forth.

•     •     •

Since I launched Vox Felina last year, I’ve been critical of articles appearing in any number of publications: scientific journals (e.g., Conservation Biology), major newspapers (e.g., The Washington Post and The New York Times), an alt-weekly, and more.

None of which bothered me in the least, as I feel no particular connection to any of them. This is not to say that I don’t value, admire, and respect much of the work found, for instance, in the Times—only that I’ve no affinity for, or loyalty to, the paper itself.

But Mother Jones is different. Maybe it’s that whole bullshit-busting, take-no-prisoners, tell-it-like-it-is business—I’d like to think that’s something we share in common.

This time around, though, the magazine served up bullshit by the shovelful, swallowed in one gulp the misinformation churned out by ABC, The Wildlife Society, and other TNR opponents, and… well, told it like it isn’t.

With the publication of “Faster, Pussycat!,” Mother Jones failed miserably in its promise to readers. Which, I have to think, isn’t a lot of fun.

Literature Cited
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627–629. www.abcbirds.org/abcprograms/policy/cats/pdf/Lepczyk-2010-Conservation%2520Biology.pdf

2. 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

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

4. 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

5. Klem, D., “Glass: A Deadly Conservation Issue for Birds.” Bird Observer. 2006. 2. p. 73–81. http://www.massbird.org/BirdObserver/index.htm

6. 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

7. 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

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

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. 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://www.ingentaconnect.com/content/bsc/ibi/2008/00000150/A00101s1/art00008

11. 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

12. 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.

13. 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.

14.  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

15. 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

16. 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

17. 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

18. 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

19. 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. http://www.carnivoreconservation.org/files/thesis/nutter_2005_phd.pdf

20. 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

21. Tennent, J., Downs, C.T., and Bodasing, M., “Management Recommendations for Feral Cat (Felis catus) Populations Within an Urban Conservancy in KwaZulu-Natal, South Africa.” South African Journal of Wildlife Research. 2009. 39(2): p. 137–142. http://dx.doi.org/10.3957/056.039.0211

22. Tennent, J. and Downs, C.T., “Abundance and home ranges of feral cats in an urban conservancy where there is supplemental feeding: A case study from South Africa.” African Zoology. 2008. 2: p. 218–229. http://login.ezproxy1.lib.asu.edu/login?url=http://search.ebscohost.com/login.aspx?direct=true&db=eih&AN=47391224&site=ehost-live

23. Hettinger, J., “Taking a Broader View of Cats in the Community.” Animal Sheltering. 2008. September/October. 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

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

25. 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

26. Barcott, B. (2007, December 2, 2007). Kill the Cat That Kills the Bird? New York Times, from http://www.nytimes.com/2007/12/02/magazine/02cats-v–birds-t.html

27. 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

28. 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

Spoiler Alert

Coming up this Wednesday: “Impacts of Free Roaming Cats on Native Wildlife,” a Webinar sponsored by the U.S. Fish and Wildlife Service. Registration, from what I can tell, appears to be open to the public—though I’m still awaiting a confirmation e-mail (which will include, I hope, some clarification re: time zone for this “2:00–3:00 pm” event).

The USFWS Website lists the agency’s own Tom Will as the scheduled speaker, and includes the following description:

A rapidly growing feral and unrestrained domestic cat population kills an average of at least 1.5 million birds in the U.S. every day—and even greater numbers of small mammals and herptiles. Every small songbird species is vulnerable at some stage of its life cycle. Despite ample peer-reviewed science documenting the failure of trap-neuter-release (TNR) programs to reduce cat populations or address wildlife depredation, TNR and outdoor cat feeding colonies continue to be marketed to city councils, county boards, and state legislatures as a viable option. As a result, TNR feeding colonies are proliferating across the landscape at such an alarming rate that wildlife conservation programs intended to create source habitat are being rendered ineffectual in many areas. In this presentation, I briefly review the science on the effects of outdoor cats on wildlife and the ineffectiveness of TNR programs. Then, examples of the decision making process leading to community endorsement of TNR provide some insight into the roadblocks to effective conservation action. Finally, I offer a suite of strategic conservation actions at national agency, community, and home scales whereby the Service and its partners might work effectively to reduce the negative effects of irresponsible civic TNR decisions on wildlife trust resources.

I expect, given Will’s apparent interest in the science surrounding this issue, that he’ll shed some light on the origins of that 1.5 million birds/day predation rate—which, translated to an annual figure, is pretty close to what the American Bird Conservancy uses in The American Bird Conservancy Guide to Bird Conservation: “532 million birds killed annually by outdoor cats.” [1]

This Webinar, then, could be our chance to see the science behind the number. Or not—if this week’s presentation is anything like the one Will gave in 2010 to the Bird Conservation Alliance (which, according to its Website, is “facilitated by” ABC). Last year’s show, “What Can Federal Agencies Do? Policy Options to Address Cat Impacts to Birds and Their Habitats,” available (downloadable PDF) via the Animal Liberation Front Website, was short on science and long on rhetoric (and plenty of misinformation, too).

Now, I’ve no way of knowing what Will is going to present this week. So, although these things tend to be remarkably predictable, I’ll reserve judgment.

That said, it seems like a good time for a quick look at his 2010 material.

Birds of a Feather
As it happens, Tom Will is among those Nico Dauphine thanks “for helpful information, advice, ideas, and discussion in researching this subject” in her 2009 Partners In Flight conference paper. [2] And much of the material Will used last year was shown a year earlier by Dauphine, in her infamous “Apocalypse Meow” presentation. (The similarities are uncanny, actually: identical background color, many of the same images, etc.)

Death by (Faulty) Statistics
Like Dauphine, Will includes the graph (shown below) from the second edition of Frank Gill’s Ornithology, suggesting, apparently, that predation by cats far exceeds all other sources of mortality combined (a claim Dauphine made in her 2008 letter to the editor of the St. Petersburg Times).

But, as I’ve explained previously, Gill’s cat “data” aren’t data at all, but the indefensible (in terms of its lack of scientific merit, but also its almost palpable bias) guesswork of Rich Stallcup, co-founder of the Point Reyes Bird Observatory.

All of which raises serious doubts about USFWS’s commitment “to using sound science in its decision-making and to providing the American public with information of the highest quality possible.”

Counting Cats
The more intriguing visual, though, in Will’s 2010 presentation (shown below) is meant (it seems) to illustrate the relationship between the increasing population of cats and the decreasing populations of bird species over the past 40 years or so.

But, of course, correlation is not the same as causation. I’ll bet that, like cat ownership, membership in the National Audubon Society has risen steadily over the past 40 years—but somehow, I don’t imagine anybody suggesting that bird populations decline as NAS membership climbs.

What first caught my eye was not the the implied relationship between cat numbers and bird numbers, however, but the red dots themselves. The same data were plotted (as shown below) in “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.,” [3] published last year in Conservation Biology, (among the paper’s 10 co-authors, by the way: Nico Dauphine and Peter Marra).

Look closely at the two graphs, and you’ll see that Will has gotten creative here. His data points (which, I believe, come primarily from the U.S. Census and APPA) are identical to those used in the letter to Conservation Biology, but the vertical scale’s been changed. In Will’s version, the upper right portion of the graph has jumped from 90 million to 150 million cats! (His horizontal axis is shifted slightly, but the impact is nothing by comparison.)

Apparently, Will is combining population data for pet cats with data for feral cats. Trouble is, his “data” for feral cats doesn’t exist. It looks as if Will simply borrowed from Dauphine, who borrowed from David Jessup—whose “estimate” is unattributed.

So much for “using sound science” and “providing the American public with information of the highest quality possible.”

Roaming Charges May Apply
What if Will stuck to what the data actually show? It seems the message is pretty clear: since 1971, the number of pet cats in the U.S. has nearly tripled.

OK, but what does that mean for the nation’s wildlife? Keep in mind: the country’s human population swelled by 43 percent over the same period, taking an enormous toll on wildlife—either directly (e.g., loss of habitat via development, birds colliding with buildings, etc.) or indirectly (e.g.,  increased pollution and pesticide use).

Let’s set all that aside for the moment, though, and get back to pet cats. Even if the graphs accurately reflect the upward trend of cat ownership in the U.S. (and I’m not sure they do), they grossly misrepresent the threat to wildlife—which, presumably, is the point.

Simply put, there are not three times as many pet cats outdoors today.

The data I have, from the American Pet Products Association, [4] go back only to 1998. At that time, 56 percent of cat owners responding to APPA’s National Pet Owners Survey indicated that their cats were indoors-only; in 2008, that figured had climbed to 64 percent.

With an estimated 89.6 million pets cats in the U.S. in 2010, then, that means that about 32.4 million cats are outdoors for at least some part of the day (and approximately half of those are outside for less than three hours each day [5, 6]).

What was the proportion in 1971? Unfortunately, I’ve been unable to find any survey results from the 1970s or 1980s. All we can do it guess.

Let’s say that in 1971 just one-third of pet cats were kept indoors exclusively (the very situation Dauphine would have us believe we’re facing today). That means 21.5 million cats were free-roaming for at least some part of the day.

Again, this is a guess—not an unreasonable one, but a guess anyhow. Still, the implications are significant. While it’s true that the number of pet cats has tripled over the past 40 years, the number that are free-roaming has probably increased by only 50 percent or so.

Prosecution or Persecution?
Finally, I’m curious to see if Will’s “suite of strategic conservation actions” will include, as his 2010 presentation suggests, threatening those who conduct or officially endorse TNR with prosecution under the Endangered Species Act (ESA) and the Migratory Bird Treaty Act (MBTA).

This has become a common tactic in recent years (see, for example, the Florida Keys National Wildlife Refuges Complex Integrated Predator Management Plan/Draft Environmental Assessment, released earlier this year), though it goes back to at least 2003, when Pamela Jo Hatley, then a law student, suggested the possibility.

(One wonders if USFWS, the agency responsible for drafting the Keys Predator Management Plan, could be prosecuted under the ESA and MBTA in the event—not unlikely—that a large-scale round-up of feral cats resulted in a population explosion of rats, which in turn decimate the very species the Plan claims to protect.)

•     •     •

As a say, I’m not going to critique Will’s presentation until he’s had the chance to give it. Indeed, he may very well deliver on the science review, policy insights, conservation actions, etc. If what he provided the BCA is any indication, though, the man’s got his work cut out for him.

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. 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

3. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627–629. www.abcbirds.org/abcprograms/policy/cats/pdf/Lepczyk-2010-Conservation%2520Biology.pdf

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

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. 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

Apocalypse Meow: A Brief Review

Although Nico Dauphine has yet to be suspended from her duties at the Smithsonian’s Migratory Bird Center, it seems all the attention she’s received over the past week-and-a-half is making life rather uncomfortable for her supporters.

Last week, the National Zoo removed Dauphine’s online application for recruiting field assistants from its Website; this week, the University of Georgia’s Warnell School of Forestry and Natural Resources pulled her infamous “Apocalypse Meow” presentation from its site.

Which is understandable, given the circumstances. Far more puzzling is what it was doing there in the first place. The content is, not surprisingly, remarkably “selective” in terms of the science. What is surprising, though, is Dauphine’s delivery: she looks and sounds like a person without the least bit of conviction in the material she’s presenting. (Actually, she’s mostly reading to the audience—for 41 minutes.)

Dauphine (whose status hearing, originally scheduled for June 1, has been postponed until the 15th) presented “Apocalypse Meow: Free-ranging Cats and the Destruction of American Wildlife” in March of 2009, at Warnell (where she earned her PhD). Although she tells the audience that her goal “is to review and present the best available science that we have,” what she delivers is essentially no different from what she presented in her Partners In Flight conference paper [1]  (much of which is recycled in the current issue of The Wildlife Professional in a special section called “The Impact of Free Ranging Cats” [2]).

In other words: lots of exaggerated and misleading claims—and plenty of glaring omissions (i.e., the distinction between compensatory and additive predation).

Included in the section on predation are all the usual suspects: Longcore et al., [3] Coleman and Temple, [4] Crooks and Soulé, [5] PhD dissertations by both Christopher Lepczyk [6] and Cole Hawkins, [7] along with references to Linda Winter, David Jessup, [8] Pamela Jo Hatley, and others.

Among the highlights:

Invasive Species (of All Kinds)
Referring to island extinctions, Dauphine references a 2008 paper by Dov Sax and Steven Gaines—the same one the U.S. Fish and Wildlife Service cite (again, as “evidence” of island extinctions caused by cats) in their Florida Keys National Wildlife Refuges Complex Integrated Predator Management Plan/Draft Environmental Assessment, released earlier this year. As I point out in my response to the Keys plan, though, the Sax & Gaines paper isn’t about cats at all, but invasive plants. [9]

Magic Multipliers
For Dauphine, Lepczyk’s estimated 52 birds/cat/year predation rate simply isn’t enough. Studies using “prey returns,” she argues, underestimate the real damage. “Some studies using radio-collars and other techniques have shown that, typically, cats will return maybe one in three kills that they make, and sometimes not at all—so this is, again, a very conservative estimate of the actual number of kills.”

But Lepczyk’s PhD work wasn’t based on “prey returns” at all. He used a survey (one of many flaws), asking landowners, “how many dead or injured birds a week do all the cats bring in during the spring and summer months?” [6]

And the idea that cats return only one in every three kills? That’s based on some wonky analysis by Kays and DeWan, who studied the hunting behaviors of just 24 cats: 12 that returned prey home, and another 12 (11 pets and 1 feral) that were observed hunting for a total of 181 hours (anywhere from 4.8–46.5 hours per cat). [10]

The Selective Generalist
Dauphine stretches Hawkins’ conclusions (which Hawkins himself had already stretched past the point of being defensible) to suggest “a sort of preferential prey take for native species in some cases, by cats.” In other words, the cats might target native species.

Or not. Less than two minutes later, Dauphine’s making the case for hyperpredation—the devastating impact on native prey species (e.g., seabirds) brought about by a large population of cats supported largely by predation on an introduced prey species (e.g., rabbits).

From Millions to Billions
It’s difficult not to see Dauphine’s assertion that “it’s not productive to argue about the numbers”—which comes fairly early in her presentation—as disingenuous when she tries repeatedly to quantify predation levels (each of which is then qualified as “conservative”). Her use of a graph included in the second edition of Frank Gill’s Ornithology (shown below) is particularly interesting.

Now, the original source of Gill’s cat “data,” as Dauphine acknowledges, is Rich Stallcup’s 1991 article, “A reversible catastrophe”—inexplicably, the only source Gill cites when he refers to predation by cats: “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…” [11]

And where does Stallcup’s “data” come from?

“He simply argued—he didn’t do a study—he just argued that if one in ten of those cats kills one bird per day, already then we have 1.6 billion cat-killed birds per year,” explains Dauphine. “We actually know that the numbers are much larger. For instance, he’s starting out with 55 million pet cats; we know there are over 100 million outdoor cats in this country, and possibly far more. We also know from some studies that 80 percent of cats hunt, and the number of birds killed per year are probably much higher. So again, just to emphasize: this is a conservative estimate.”

In fact, Stallcup’s “estimate” is even flimsier than Dauphine suggests:

“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).” [12]

Shocking, yes. True? Why would anybody think so? (I can see the appeal for Dauphine, though: like her, Stallcup grossly overestimates the number of pet cats allowed outdoors.)

(The fact that this absurdity made it—however well disguised—into a standard ornithology textbook may explain a great deal about the positions frequently taken by today’s wildlife managers and conservation biologists regarding feral cats/TNR.)

Apocalypse Now
Perhaps the strangest—almost surreal—part of “Apocalypse Meow” comes when, to illustrate her point that the (over)heated TNR debate can “result in a lot of misunderstandings, misinformation, and hard feelings,” Dauphine refers to an e-mail sent out to the university’s CATSONCAMPUS listserv during the fierce TNR debate in Athens, which read in part:

“There are some folks in the area (and all over) who are not only Anti-TNR, they also hate felines so much that some of them want to round up the cats in the area and kill them.”

Two years later, this is pretty much what Nico Dauphine stands accused of.

Literature Cited
1. 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

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

3. 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

4. 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

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. 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

7. 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

8. 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

9. 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

10. 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. http://dx.doi.org/10.1017/S1367943004001489

www.nysm.nysed.gov/staffpubs/docs/15128.pdf

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

12. 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

Perfectly Comfortable? I’m Not.

As many of you know, the National Zoo has shown no signs of suspending Nico Dauphine, despite her recent arrest on charges of attempted animal cruelty. As a result, at least two petitions are being circulated—one by Alley Cat Rescue, and another by Alley Cat Allies.

I encourage readers to sign both petitions, and also to send letters (an online form is available here). Below is my letter to National Zoo director Dennis Kelly:

Dear Dennis Kelly,

As you know, the National Zoo’s mission emphasizes leadership—in animal care, science, and education—as well as “the highest quality animal care.” But recent events indicate that Zoo management has lost sight of this noble mission.

Indeed, allowing Dr. Nico Dauphine—recently charged with attempted animal cruelty in connection with the poisoning of cats in her neighborhood—to continue her work for the Zoo’s Migratory Bird Center demonstrates a profound lack of leadership, and suggests a remarkably narrow view of “animal care.”

Comments made last week by the Zoo’s associate director of communications, Pamela Baker-Masson, only made matters worse—suggesting that Zoo management isn’t even aware of the research Dauphine is conducting. Baker-Masson told ABC News:

“We know what she’s doing would in no way jeopardize our animal collection at the National Zoo or jeopardize wildlife, so we feel perfectly comfortable that she continue her research.”

But, according to the Migratory Bird Center’s Website, Dauphine’s “current project examines predator-prey dynamics in an urban matrix in collaboration with citizen scientists at Neighborhood Nestwatch.”

The predators in this case are, of course, house cats. And, according to an online application form she’s been using to recruit field assistants (the form was recently removed from the Migratory Bird Center’s Website), Dauphine is asking participating citizen scientists to put cameras on their cats.

And still, the National Zoo feels “perfectly comfortable that she continue her research.” What kind of message does this send to the local community, and to the nation as a whole?

The Smithsonian’s 2009 Annual Report indicates that 75 percent of the organization’s revenue comes from “federal appropriations” (63 percent) and “government grants and contracts” (12 percent). One way or another, these are tax dollars. In standing by Dauphine, then, the National Zoo is violating the trust of its primary funding source: the American people (among whom, 38.9 million households own cats).

Finally, the National Zoo should use the current crisis as an opportunity to review its hiring practices. I think it’s safe to say that Dauphine’s reputation preceded her when she joined your organization. Her extreme position against TNR—and free-roaming cats in general—is well documented. As is her habit of misrepresenting the science surrounding the issue.

In her February 10, 2008, letter to the editor of the St. Petersburg Times, for example, Dauphine—who identifies herself as “a scientist who has studied this issue”—makes an outlandish claim:

“In North America, cats may be the single biggest direct cause of bird mortality, far outnumbering all other causes (including human hunters) put together!”

Not even the American Bird Conservancy—which has, for the past 15 years, taken every opportunity to demonize free-roaming cats—goes this far.

And yet, the National Zoo has Dauphine, together with Dr. Peter Marra (who, in a letter co-authored with Dr. Dauphine, has called TNR “cat hoarding without walls.”), [1] researching the hunting habits of house cats. All of which raises questions about the rigor and validity of the research being conducted—not to mention the integrity of those involved.

As the National Zoo’s director, you have the responsibility to address these issues. I am, therefore, asking you to start by suspending Dr. Dauphine until the charges of attempted animal cruelty are dropped, proven to be unfounded, or in some other way resolved.

Respectfully,

Peter J. Wolf
Independent Researcher/Analyst
Vox Felina

Literature Cited
1. Lepczyk, C.A., et al., “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” Conservation Biology. 2010. 24(2): p. 627–629. www.abcbirds.org/abcprograms/policy/cats/pdf/Lepczyk-2010-Conservation%2520Biology.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

Catbirds, Cats, and Scapegoats

Gray CatbirdA Gray Catbird in Madison, Wisconsin, USA. Photo courtesy Wikimedia Commons and John Benson.

Once again, the Smithsonian has apparently put marketing (and perhaps politics, too) ahead of science, reviving a story first posted on the Smithsonian Migratory Bird Center’s (SMBC) Website in October of last year (which has since been removed).

“Alarming number of fledgling, suburban catbirds fall prey to domestic cats, study finds,” reads the headline of the most recent version—posted not on the SMBC site, but as a feature story on Science at the Smithsonian, “a new Website from the Smithsonian Office of Public Affairs.” So what’s changed in the four months since I first commented on the story? Only the publication of the research involved: “Population demography of Gray Catbirds in the suburban matrix: Sources, sinks and domestic cats” by Anne L. Balogh, Thomas B. Ryder, and Peter P. Marra (all of whom are affiliated with the Migratory Bird Center) appeared in the January issue of the Journal of Ornithology.

Whoever wrote the piece for the Smithsonian, though, doesn’t seem to have read the paper.

Indeed, it seems the people responsible for its publication are far more interested in making scapegoats out of the cats than they are in science, or science journalism.

Predation: Real and Imagined
According to the Smithsonian, “Nearly half (47 percent) of the [juvenile catbird] deaths were attributed to domestic cats in Opal Daniels and Spring Park.”

In “Population demography of Gray Catbirds,” the authors report that the Opal Daniels and Spring Park sites accounted for 34 of 42 total juvenile mortalities. [1] The presumption, then, is that 16 (47 percent) are due to cats. However, cats accounted for—at most—just nine of the 42 total mortalities (no breakdown regarding cat kills/site is provided in the paper).

Something doesn’t add up here—and I suspect it’s no accident.

But attributing even nine kills to cats is highly questionable; only six were actually observed. The researchers then attributed three additional kills to cats, claiming: “we are unaware of any other native or non-native predator that regularly decapitates birds while leaving the body uneaten.” [1]

As I’ve pointed out previously, though, a survey of several credible sources [2–5] turns up no supporting evidence. Anderson, describing “predation and its identification,” goes into some detail:

“Domestic cats rarely prey on anything larger than a duck, pheasant, or rabbit. Einarsen (1956) noted their messy feeding behavior. Portions of their prey are often strewn over several hundred square feet in open areas. The meaty portions of large birds are almost entirely consumed leaving loose skin with feathers attached. Small birds are generally consumed, with only the wings, and scattered feathers remaining. Cats usually leave teeth marks on every exposed bone of their prey.” [6]

Raccoons, writes Anderson, are also known to “prey on birds and their eggs. The heads of adult birds are usually bitten off and left some distance from the body (Anon. 1936).” [6]

And it seems to be common knowledge within the birding community that certain species of birds decapitate their prey:

“In urban and suburban settings grackles are the most likely culprits, although jays, magpies, and crows will decapitate small birds, too. Screech-owls and pygmy-owls also decapitate their prey, but, intending to eat them later, they usually cache their victims out of sight.” [7]

“There is little you can do to discourage screech-owls if only because they do their killing under cover of darkness. However, you can recognize their handiwork by looking for partially plucked carcasses of songbirds with the heads missing… Corvids—crows, ravens, jays, and magpies—are well known for their raids on birds’ nests to take eggs and nestlings.” [8] (Interestingly, the author, David M. Bird, was among Marra’s nine co-authors on “What Conservation Biologists Can Do.”)

Balogh, Ryder, and Marra also point out that another “potential nest predator,” the gray squirrel, was more common at the Opal Daniels and Spring Park sites than at the Bethesda site. [1] And roughly three to five times as abundant as cats, based on researcher sightings. Yet the squirrels aren’t mentioned at all in the Smithsonian story.

Populations and Ecological Traps
In addition, Marra’s suggestion that “these suburban areas [are] ecological traps for nesting birds” is contradicted by the results of bird surveys in Maryland.

The Atlas of the Breeding Birds of Maryland and the District of Columbia, for example reports: “during the Atlas period [1983–87], gray catbirds were found throughout the state, including the most heavily urbanized blocks.” The Atlas goes on to note the bird’s “high tolerance for human activity,” concluding that “the gray catbird’s future in Maryland seems secure.” [9]

Data from the Atlas indicate that Maryland’s gray catbird population declined perhaps 7 percent between 1966–1989, a period during which the state’s human population grew approximately 35 percent. (Note: In my previous post on this topic, I mistakenly suggested that the Atlas used Breeding Bird Survey (BBS) data, which is not the case.)

The North American Breeding Bird Survey indicates that Maryland’s gray catbird population has increased about 9 percent between 1966–2009, a period during which the state’s human population grew approximately 57 percent. And data from BBS Route 46110, the nearest to the research sites, also trend upward in recent years. (Note: It’s important to point out that “the survey produces an index of relative abundance rather than a complete count of breeding bird populations.”)

Maryland Catbirds 1966-2007Caption: BBS Data: Gray Catbird Counts Across Maryland, 1966–2007

The Migratory Bird Center’s Website, too, suggests the outlook for the catbird population is quite good:

“To thrive in these [fragmented] habitats birds must have special adaptations such as the ability to respond to frequent nest predation and parasitism and to forage on a wide variety of seasonally available foods. Armed with these adaptations, catbirds are well prepared for the disturbed habitats of the 21st century’s fragmented landscape.”

•     •     •

Marra revealed his position on free-roaming cats last year in that letter to Conservation Biology opposing TNR. Among the “highlights” were the authors’ assertion that “trap-neuter-return is essentially cat hoarding without walls,” and a demand for “legal action against colonies and colony managers.” The authors also call on conservation biologists to “begin speaking out” against TNR “at local meetings, through the news media, and at outreach events” (a message Marra has obviously taken to heart).

In the past couple of months, the Smithsonian has raised questions about its own stance on free-roaming cats, first with its World’s Most Invasive Mammals story, and now this. In both cases, their reporting has been either careless or intentionally misleading.

According to its Website, the Smithsonian Migratory Bird Center is a “national and international leader in the biology and conservation of migratory birds.” In this case, though, it seems the SMBC—and, by extension, Science at the Smithsonian—have abdicated any leadership role in order to participate in the shameful witch hunt against free-roaming cats.

The Institution’s supporters—and the public at large—expect and deserve better.

Literature Cited

1. 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

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

3. Leyhausen, P., Cat behavior: The predatory and social behavior of domestic and wild cats. Garland series in ethology. 1979, New York: Garland STPM Press. xv, 340 p.

4. 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.

5.  Turner, D.C. and Meister, O., Hunting Behaviour of the Domestic Cat, in The Domestic Cat: The Biology of Its Behaviour, D.C. Turner and P.P.G. Bateson, Editors. 1988, Cambridge University Press: Cambridge. p. 222.

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

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

8. Bird, D.M., Crouching Raptor, Hidden Danger, in The Backyard Birds Newsletter. 2010, Bird Watcher’s Digest.

9. Robbins, C.S. and Blom, E.A.T., Atlas of the breeding birds of Maryland and the District of Columbia. Pitt series in nature and natural history. 1996, Pittsburgh, PA: University of Pittsburgh Press. xx, 479 p.

Freedom of the Press (Release)

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

And what’s the impact of this predation?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

That does sound heartbreaking. But is it true?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

And, it just keeps on coming.

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

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

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

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

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

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

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

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

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.

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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.

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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.

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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.

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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

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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.

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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/

Rap(tor) Sheet

Perhaps it’s an act of desperation, this “kitchen sink” approach favored by some free-roaming cat/TNR opponents. Throw everything—including the kitchen sink—into the anti-cat argument, and perhaps something will stick. Their impact on wildlife and the environment, for instance, or their threat to public safety—it seems there’s something for everybody. (Surely it’s only a matter of time before beach erosion, ozone depletion, and climate change are added to this growing rap sheet.)

But for those of us willing to sort through this quantity-over-quality smokescreen, such arguments rarely prove substantive.

I touched on this point in one of my first Vox Felina posts, referring to how the now-classic predation study conducted by William G. George has been misread, misinterpreted, and misrepresented. This work, perhaps more than any other, has been used to suggest an indirect impact of free-roaming cats on raptors.

George was very cautious about drawing such a connection, acutely aware of the speculative nature of his own work. In recent years, however, the details of George’s work—and his well-tempered conclusions—have given way to a kind of mythology, having been co-opted by scientists more interested in their own agendas than in rigorous scientific inquiry.

The Study
Over four years, from January 1, 1968 through December 31, 1971, George monitored and recorded with meticulous care the various small mammals his three cats killed on his “fallow farmland” property in rural Cobden, Illinois. “As predators on rodents,” writes George, “cats inevitably compete for prey with many of our declining raptors, and therein may lie a serious problem.” (emphasis mine) [1].

“I am not suggesting a cause-and-effect relationship exists between the historical increase of cats and the historical decrease of raptors; however, cats, which are as efficient in their way as guns and DDT, accompany and add another dimension to man’s encroachment into wildlife areas.” [1]

The trouble, of course, is that so many scientists citing George’s work have suggested exactly that.

The Myth
“Cat predation on mammals,” write Longcore et al., is “cause for concern because of direct impacts to native species and competition with native predators (George 1974).” [2] “Human-subsidized cats,” warn Guttilla and Stapp, “can spill over into less densely populated wildland areas where they reduce prey for native predators (George 1974).” [3]

Of course anybody who grew up, as I did, watching Wild Kingdom, knows that competition is a central theme of many stories played out in the natural world. But competition for prey is one thing; having an impact on the population of competitors is something else altogether.

Which is precisely what Loyd and DeVore—citing only George’s research—suggest: “Feral cats can also have a considerable impact on the broader health of ecosystems by outcompeting native predators (George 1974)…” [4]

Dauphiné and Cooper, too, interpret George’s work rather loosely, but also seem to offer additional evidence of the indirect impacts about which he speculated:

“In addition to having direct impacts on prey, cats compete with avian predators, such as American Kestrels (Falco sparverius), Northern Harriers (Circus cyaneus), and Redtailed Hawks (Buteo jamaicensis) (George 1974, Mosher 1989, Lepczyk et al. 2004). George (1974) estimated that cats killed 5.5 million rodents and other vertebrates in a 26,000 square mile area in Illinois, effectively depleting the prey base for wintering raptors and other native predators.” [5]

What did Lepczyk add to the conversation? Nothing, actually; he merely cited George’s study:

“… cats may be directly competing with avian predators, such as American Kestrels (Falco sparverius), Northern Harriers (Circus cyaneus) and Red-tailed Hawks (Buteo jamaicensis; George, 1974).” [6]

And Mosher? This one’s far more interesting. According to Dauphiné and Cooper, Mosher’s research reveals some compelling evidence:

“In a study in Maryland of Cooper’s Hawks (Accipiter cooperii) that depended heavily on eastern chipmunks (Tamias striatus) to feed nestlings, Mosher (1989) found that these raptors altered their diet to prey more on songbirds in an area where chipmunks were eradicated by cats. The resulting increase in hunting time and difficulty for Cooper’s Hawks was associated with a decrease in nestling survival.” [5]

But Mosher’s paper includes no mention of cats at all. In fact, he suggests only “that reproductive performance, especially in studies encompassing relatively small areas, may reflect natural phenomena such as dependence on a particular prey species that undergoes population fluctuations.” [7] I found an earlier paper by Mosher, also mentioning chipmunks and Cooper’s Hawks [8]—but again, no mention of cats.

It’s possible this is an honest mistake, that Dauphiné and Cooper merely included the wrong reference. However, I was unable to find a hint of any such research in my (admittedly brief) online sleuthing. And, given the sloppiness and bias that permeates the rest of their paper, nothing these two might do would surprise me.

(If, as Dauphiné and Cooper suggest, the real problem is that raptors are preying on songbirds rather than chipmunks, then shouldn’t we be doing everything in our power to increase the chipmunk population? It’s an absurd suggestion, of course—but only slightly more so than many accepted wildlife “management” practices.)

Getting back to George’s research, the winner for most distorted version undoubtedly goes to David Jessup, who writes with a certitude generally reserved for politicians, marketers, and novelists. Gone is the trepidation 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.” [9]

Local/Regional Raptor Update
So, how have those raptors fared in the subsequent 40 years? Certainly there are factors other than cats that would likely contribute to their decline—habitat fragmentation and destruction, for instance. Such environmental impacts have the potential to affect the birds themselves, clearly, but also their prey.

Research into the population trends of Red-tailed Hawks, Northern Harriers, and American Kestrels—three raptors identified specifically by George—suggests that his concerns were largely unfounded.

BBS Routes and Data
Only one Breeding Bird Survey (BBS) route runs into Union County, Illinois, where George’s property was located. Unfortunately, count data for BBS Route 34080 go back only to 1993. However, data for neighboring routes are available from the time of George’s study through 2006. Surveys along two nearby routes in Illinois (34059 and 34061) began in 1970; surveys of two others, along the eastern edge of Missouri (52001 and 52007), date back to 1967.

Selected BBS Routes: Missouri and Illinois

No BBS count data from the routes in question are available for Northern Harriers, suggesting that perhaps this species was, for one reason or another, simply not included. Data sets for other birds—the Red-shouldered Hawk, for example—exist despite frequent counts of zero (in the case of the Red-shouldered Hawk, just one bird was recorded along Routes 52001 from 1967 through 2006).

BBS data for Red-tailed Hawks indicate a rather dramatic population increase for the two southwestern Illinois routes, and slight increases for the same period across the two eastern Missouri routes, as indicated in the following graphs.

Red-tailed Hawks Four BBS RoutesBBS Data: Red-tailed Hawks for two Illinois and two Missouri routes (adapted from North American Breeding Bird Survey website)

Populations of American Kestrels (along the same routes and for the same period) remained mostly stable.

American Kestrels Four BBS RoutesBBS Data: American Kestrels for two Illinois and two Missouri routes (adapted from North American Breeding Bird Survey website)

The bottom line? If the area’s cats are out-competing the raptors for prey, there’s no evidence in the BBS count data.

Prairie Voles
Of particular interest to George were prairie voles, which made up “more than 41 percent of all captured vertebrates and 45 percent of the captured mammals.” [1] And whose reduced numbers, suggested George, “could well pose the principal threat to the success of wintering hawks in my area of study.” [1] But maybe the voles weren’t as important as George surmised.

In Minnesota, the declining population of prairie voles—significant enough to warrant “special concern species” status beginning in 1984—seems to have had no effect on the populations of Northern Harriers, Red-tailed Hawks, and American Kestrels. Indeed, BBS data indicate that these raptors’ numbers have fluctuated little over the past 40 years or so. (And, according to the Minnesota Department of Natural Resources, the reason for the state’s declining vole numbers has nothing to do with cats, but “is due almost exclusively to the destruction of its prairie habitat through plowing and over-grazing.”)

BBS Data: Three Raptors across MinnesotaBBS Data: Three raptor species across Minnesota (adapted from North American Breeding Bird Survey website)

Raptors Across the Country
Of course, isolating the relationship between the population of a predator and that of its preferred prey species is incredibly difficult; there are simply too many additional—often interdependent—factors that must be considered. Zooming out for a big-picture view of population dynamics across the U.S. only blurs such relationships, thereby complicating any subsequent analysis.

Nevertheless, I think it’s worth a look. George claimed (unfortunately, without referring to a specific source, and without specifying whether he was referring only to owned/pet cats) that there were 31 million cats in the U.S. at the time of his study. [1] Today, according to the American Pet Products Association’s 2009–2010 National Pet Owners Survey, there are 93.6 million.

Direct comparisons over this 40-year time frame are difficult for a number of reasons (e.g., lack of reliable data, the increasing proportion of indoor-only cats in recent years, etc.). But if, as some suggest, cats are having an negative impact on raptor populations—and there are now three times as many of them (not accounting for feral cats, whose numbers have also likely increased)—well, one might expect find these birds in dire straights by now.

Hawk Mountain Sanctuary
To see for myself, I turned to Hawk Mountain Sanctuary’s Conservation Status Reports. Located in east-central Pennsylvania, Hawk Mountain Sanctuary is, according to its website, “the world’s first refuge for birds of prey.”

The outlook for the Northern Harrier and Red-tailed Hawk is mostly good. “The Northern Harrier is considered secure in most of North America,” notes its 2007 conservation report, “but it is a species of concern regionally in many of the [Bird Conservation Regions] west of the Mississippi River.”

The Red-tailed Hawk, too, “is considered secure throughout most of its range in North America.

“Migration counts have declined in eastern North America since 1995, but concurrent increases in [Breeding Bird Surveys] and [Christmas Bird Counts] suggest that these migration trends may be the result of changes in migration geography or behavior. Elsewhere in North America, population monitoring generally indicates increasing or stable populations of this common raptor.”

American Kestrels, on the other hand, seem to be in trouble: “Overall, the data suggest substantial declines in populations… across much of North America, and consequently strong cause for conservation concern.” The factors affecting these declines are unknown and, the report notes, “warrant further investigation.” However, some patterns have been observed—“factors exerting negative influences on populations are strongest along the Atlantic coast,” for example. Also: “More recent declines in western North America… appear to have occurred in concert with a prolonged drought.”

The Cornell Lab of Ornithology’s website paints a rather different picture, noting that the population of American Kestrels “increased greatly with historical deforestation of North America. No significant trend across North America, but some local increases and decreases.”

*     *     *

All of which adds up to… what? Like the BBS data, the Hawk Mountain Sanctuary Conservation Status Reports reveal population trends perhaps best described as “mixed.” Nowhere is there any indication that declining raptor numbers can be linked to the success of competing predators—including cats.

For George, the idea was nothing more than a hypothesis anyhow. But rather than put it to the test (ostensibly the role of scientists), Longcore, Dauphiné, Jessup, and the rest, have instead tried to elevate its status through nothing more than repetition—thereby betraying an agenda that has little to do with science at all.

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. elibrary.unm.edu/sora/Wilson/v086n04/p0384-p0396.pdf

2. 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.

3. 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

4. Loyd, K.A.T. and DeVore, J.L., “An Evaluation of Feral Cat Management Options Using a Decision Analysis Network.” Ecology and Society. 2010. 15(4). http://www.ecologyandsociety.org/vol15/iss4/art10/

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. 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

7. Mosher, J.A., Accipiters, in Northeast Raptor Management Symposium and Workshop, B.A.G. Pendleton, Editor. 1989, National Wildlife Federation Scientific and Technical Series No. 13.: Syracuse, NY. p. 47–52.

8. Mosher, J.A., “Breeding Biology of Raptors in the Central Appalachians.” Raptor Research. 1982. 16(1): p. 18–24.

9. 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

A Tale of Two Cities

Gray Catbird (Dumetella carolinensis)A Gray Catbird in Madison, Wisconsin, USA. Photo courtesy Wikimedia Commons and John Benson.

According to its website, the Smithsonian Migratory Bird Center is a “national and international leader in the biology and conservation of migratory birds.” When it comes to cats and their potential impact on birds, however, the SMBC apparently has a lot to learn.

Actually, they could use some pointers on professionalism, too—and maybe a refresher on the difference between correlation and causation.

Summarizing a recent study of gray catbird fledglings in the Washington, DC area, the SMBC claims that cats were responsible for “alarmingly high rates of nest predation and fledging [sic] mortality.” But there’s no mention of how such a connection was made. Indeed, “Baby Catbird Survival” offers very little in the way of details. Instead, readers are treated to sophomoric commentary:

“… several guilty-looking cats were found in close proximity to dead birds. Our guess is that closer examination would have revealed feathers in their whiskers.”

This is the Smithsonian? What I wouldn’t give to have been in the marketing meeting where “predation humor” was first proposed as an innovative, sure-fire scheme for attracting new donors and research funding.

Catbird Mortality
The study, spanning two summers, was conducted at three sites, two in Takoma Park, MD, and another—apparently less populated with cats—in Bethesda, MD. Somehow—again, no details are given—radio-tracking technology was used to monitor the mortality of young catbirds.

Results indicate that 85% of nests at the Bethesda site were “successful” (i.e., young catbirds survived long enough to leave the nest), compared to only 34% of nests at the Takoma Park sites. At the Bethesda site, 29% of fledglings survived to eight weeks of age, versus 14% at Takoma Park.

Given the rather dramatic nature of these findings, one might expect some explanation of the research methods and analysis techniques employed. Among the numerous questions left unanswered:

  • How was radio-tracking used to distinguish predation from other forms of mortality—or, more to the point, predation by cats from other forms of predation?
  • How were the sites selected, and the cats at each site counted?
  • What other factors (e.g., population density of humans, abundance of other predators, habitat availability and condition, etc.) might have been at work here?
  • What were the sample sizes employed?

At best—and this is being very generous—the results suggest correlation. But, of course, this is very different from causation.

In Proofiness, author Charles Seife uses the relationship between a country’s energy consumption and the life expectancy of its citizens to illustrate the difference. Plot the data and there is an unmistakable trend: as energy consumption increases, so does life expectancy.

“Yes, it’s true that the more power a society uses, the longer its citizens live, on average. It’s equally true, however, that the more garbage a society produces, the longer its people live. The more automobiles people in a society drive, the more newspapers people in a society read, the more fast food people consume, the more television sets people have, the more time people spend on the Internet…” [1]

So, are the Takoma Park cats the cause of catbird mortality? Who knows.

Who’s In Charge?
Exactly who’s responsible for “Baby Catbird Survival” is another mystery (though anonymity is understandable in this case, as it’s difficult to imagine any respectable scientist claiming ownership of something so flimsy and irresponsible). The researcher who oversaw the project, though, is Peter Marra, the SMBC scientist at the center of a recent Washington Post column (of which I was highly critical).

This, of course, is the same Peter Marra who, along with nine of his colleagues, has argued that “trap-neuter-return is essentially cat hoarding without walls,” and called for “legal action against colonies and colony managers.” [2] The authors also call on conservation biologists to “begin speaking out” against TNR “at local meetings, through the news media, and at outreach events.” [2] It’s a message Marra has obviously taken to heart.

There’s no doubt Marra has an agenda. The question is: how might this bias his research?

Untangling the Research
With so few details to go by, it’s difficult to scrutinize Marra’s catbird study. If it’s published, of course, greater transparency will be required. In the meantime, we do have some useful clues that—along with a little detective work—provide some insight.

Counting Cats
As I indicated previously, it’s hard to imagine that the only difference between the Takoma Park and Bethesda sites was the number of cats. Even if that were the case, though, absolute numbers are hardly the whole story. Numerous studies have demonstrated that predation success varies widely among domestic cats: some catch lots of prey while others catch very few—or none at all. [3–7]

That’s assuming they can get at the prey, of course.

Marra is clear in the Post piece that the (alleged) killers “aren’t feral cats; they’re domestic cats allowed to go outside.” But, contrary to what columnist Adrian Higgins suggests, studies have shown that about two-thirds of cats are indoor-only. [8–11] And of those allowed outside, approximately half spend less than three hours outdoors each day. [9, 10]

How sure can Marra be, then, that the areas’ pet cats are responsible for the deaths of young catbirds?

Predatory Habits
The author of “Baby Catbird Survival” claims that “domestic cats typically only decapitate birds and leave the carcass.” Now, I’ve become quite familiar with the research on the hunting behavior of cats over the past year or so, and recall seeing nothing to this effect. I recently revisited some key sources [12–15] just to be sure, and again found nothing to support this assertion. However, it was brought to my attention that some birds will decapitate their prey:

“In urban and suburban settings grackles are the most likely culprits, although jays, magpies, and crows will decapitate small birds, too. Screech-owls and pygmy-owls also decapitate their prey, but, intending to eat them later, they usually cache their victims out of sight.” [16]

“There is little you can do to discourage screech-owls if only because they do their killing under cover of darkness. However, you can recognize their handiwork by looking for partially plucked carcasses of songbirds with the heads missing… Corvids—crows, ravens, jays, and magpies—are well known for their raids on birds’ nests to take eggs and nestlings.” [17] (Interestingly, the author, David M. Bird, was among Marra’s nine co-authors on “What Conservation Biologists Can Do.”)

Again, how can Marra be so sure the cats are the culprits?

Catbird Population
And finally, what about Marra’s claim, as reported by Higgins, that “catbirds in cat-heavy areas are not able to reproduce at a rate that is sustainable”?

Data from the North American Breeding Bird Survey suggest that Maryland’s gray catbird population declined perhaps 7% between 1966–1989, a period during which the state’s human population grew approximately 35%.

BBS Data: Catbirds Across MarylandBBS Data: Gray Catbirds Across Maryland (adapted from the Atlas of the breeding birds of Maryland and the District of Columbia)

Even so, the Atlas of the Breeding Birds of Maryland and the District of Columbia—which includes the aforementioned BBS data in its assessment—reports that, “during the Atlas period [1983–87], gray catbirds were found throughout the state, including the most heavily urbanized blocks.” The Atlas goes on to note the bird’s “high tolerance for human activity,” concluding that “the gray catbird’s future in Maryland seems secure.” [18]

Indeed, the SMBC itself echoes the Atlas’ assurances:

“To thrive in these [fragmented] habitats birds must have special adaptations such as the ability to respond to frequent nest predation and parasitism and to forage on a wide variety of seasonally available foods. Armed with these adaptations, catbirds are well prepared for the disturbed habitats of the 21st century’s fragmented landscape.”

Still, statewide figures such as those complied in the Atlas can obscure as much as they reveal. Better to look at the detailed counts from individual survey routes. And it turns out data from BBS Route 46110, the nearest to the Takoma Park and Bethesda sites, actually trend upward in recent years. (Note: It’s important to point out that “the survey produces an index of relative abundance rather than a complete count of breeding bird populations.”)

BBS Data: Gray Catbirds Along Route 46110BBS Data: Gray Catbirds Across Route 46110 (adapted from North American Breeding Bird Survey website)

All of which has me wondering about Marra’s rather dire forecast for the area’s gray catbirds—in terms of the underlying science, of course, but also the possible motives behind such a statement.

*     *     *

Publishing dodgy science within the scientific community is one thing—hardly excusable, but there is at least a reasonable expectation that one’s peers are in a position to critically evaluate such research—but to package this kind of work for public consumption is truly irresponsible. Like Higgins’ column, “Baby Catbird Survival” is a Trojan Horse: unsubstantiated—and, potentially, highly damaging—claims “wrapped up” as valid science.

Brilliant from a marketing standpoint, maybe—but it’s hardly my idea of leadership.

I’ve attempted to contact both the SMBC and Peter Marra—expressing my concerns with “Baby Catbird Survival,” but also my interest in a more complete accounting of the study’s findings. Unfortunately, neither has responded.

SPECIAL THANKS once again to Louise Holton and Maggie Funkhouser at Alley Cat Rescue for bringing the Washington Post article to my attention.

Literature Cited
1. Seife, C., Proofiness: The Dark Arts of Mathematical Deception. 2010: Viking Adult.

2. 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.

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

4. 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.

5. 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.

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

7. 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.

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

9. 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.

10. 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.

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

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

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

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.

15. Turner, D.C. and Meister, O., Hunting Behaviour of the Domestic Cat, in The Domestic Cat: The Biology of Its Behaviour, D.C. Turner and P.P.G. Bateson, Editors. 1988, Cambridge University Press: Cambridge.

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

17. Bird, D.M., Crouching Raptor, Hidden Danger, in The Backyard Birds Newsletter. 2010, Bird Watcher’s Digest.

18. Robbins, C.S. and Blom, E.A.T., Atlas of the breeding birds of Maryland and the District of Columbia. Pitt series in nature and natural history. 1996, Pittsburgh, PA: University of Pittsburgh Press.

Garden Tool

The timing was uncanny. Four days after my post “Inside Job,” Washington Post columnist Adrian Higgins reported incorrectly that two-thirds of pet cats are allowed outdoors. Higgins doesn’t mention where he got that figure, but considering the sources he used for the piece—including the American Bird Conservancy (ABC), The Wildlife Society, and Dauphiné and Cooper’s 2009 Partners in Flight paper—it’s not hard to sort out.

Ditto for his matter-of-fact assertion that “the cumulative effect on birds is significant, according to experts.” Higgins relies on Dauphiné and Cooper for estimates of both the number of “stray and out-and-out feral cats” (“there may be as many as 100 million such cats in the country”) and birds killed by free-roaming cats (“at least one billion birds are killed by cats annually, ‘and the actual number is probably much higher.’”). [1]

Higgins’ column appeared exactly one week after the release of Charles Seife’s book Proofiness: The Dark Arts of Mathematical Deception. Proofiness, writes Seife, is “the art of using bogus mathematical arguments to prove something that you know in your heart is true—even when it’s not.” [2]

Many—perhaps most—of the scientific claims made by opponents of free-roaming cats/TNR are textbook cases of proofiness. Nevertheless, they are often accepted at face value by the media, which—simply by passing them along for public consumption—gives these assertions unwarranted credibility.

Pete Marra
The central character in Higgins’ story is Pete Marra, a fellow gardener and a research associate at the Smithsonian Conservation Biology Institute. Marra’s name rang a bell.

Sure enough, this is the same Peter P. Marra who, along with nine others (including Dauphiné and Cooper), authored a comment in Conservation Biology earlier this year, entitled “What Conservation Biologists Can Do to Counter Trap-Neuter-Return: Response to Longcore et al.” (the publication of which prompted a series of Vox Felina posts, beginning with this one).

What Marra and his co-authors penned is an unapologetic call to action:

Proponents of TNR are well organized and push for TNR-friendly policies in communities and shelters around the United States, often with little opposition from the conservation biology and wildlife ecology communities… Regardless of why the scientific and management communities have remained relatively silent, it is imperative that we now begin speaking out. [2]

As I have argued, the silence that so frustrates Marra and the others may simply reflect the fact that so much of the work he and his colleagues defend is largely indefensible. Indeed, “What Conservation Biologists Can Do” is, in its own way, representative. Consider the authors’ comparison of TNR with hoarding:

The animal welfare community opposes “cat hoarding,” whereby people care for more pets than they can adequately support, because it is considered inhumane. Trap-neuter-return is essentially cat hoarding without walls. Considering that most communities have laws banning animal hoarding, we should consider the same standard for outdoor cats as those that are in a person’s home. [3]

But their interest in using the law to put a stop to TNR doesn’t end there. Marra and his colleagues continue:

…it may become incumbent upon us to take legal action against colonies and colony managers, particularly in areas that provide habitat for migratory birds or endangered species. [3]

The authors quote a 2003 article written by Linda Winter, the former director of the ABC’s Cats Indoors! campaign, for the Hawaii Audubon Society newsletter:

“…releasing cats into the wild and supporting feral cat colonies is a violation of the Migratory Bird Treaty Act and the Endangered Species Act, as well as laws prohibiting animal abandonment.” (her emphasis, not mine) [4]

As a frequent critic of Winter’s writing, I was eager to read the newsletter (which can be downloaded here). It turns out Winter was referring to a 2003 report submitted by Pamela Jo Hatley—then a student in the University of Florida’s Levin College of Law and part of its University of Florida Conservation Clinic—to the U.S. Fish & Wildlife Service.

Winter—and by extension, Marra and his colleagues—are unambiguous on this point: TNR is a clear violation of both the Migratory Bird Treaty Act and the Endangered Species Act. But, of course, law students don’t make legal decisions; that’s what we have courts for (which might explain why, years later, Travis Longcore and his Urban Wildlands Group took a rather different approach in their TNR-related lawsuit against the City of Los Angeles).

But back to Hatley—there’s another familiar name. In fact, I’d seen it right beside Marra’s earlier this year. See, Pamela Jo Hatley is one of the 10 co-authors of “What Conservation Biologists Can Do.”

So why didn’t the authors just cite Hatley’s work directly, rather than turning to Winter’s version of it? Simply put, Winter’s version is a better story—short and sweet, and brimming with certitude.

But if Marra and the others—Hatley included—wanted to distance themselves from the original, it’s understandable. Though her legal arguments are somewhat compelling, Hatley’s report is a minefield of misrepresentations, flawed estimates, and unsubstantiated claims where the science is concerned (e.g., extrapolating the Wisconsin Study to Florida, and then suggesting that “the actual number [of birds killed by cats in the state] may be much higher” [5]). In other words, more proofiness.

Its title, Feral Cat Colonies in Florida: The Fur and the Feathers Are Flying, is a good indication of how seriously the report—ostensibly a formal document submitted to a federal agency—should be taken.

Getting Dirty
To read Higgins’ column in the Post, one gets the idea that he and Marra are merely fellow gardeners, perhaps having bumped into each other at the local nursery or hardware store. And that’s where the story began. It could be.

But there’s a sentence in “What Conservation Biologists Can Do” that’s been bothering me ever since I read Higgins’ piece:

Conservation biologists have just as much opportunity to make their points at local meetings, through the news media, and at outreach events as do TNR proponents. (emphasis mine) [2]

I have no idea whether Higgins and Marra knew each other before Higgins began work on his column, or how Higgins feels about cats. And I’m not one to go in for conspiracy theories, either.

What I am sure of is that Higgins—as a journalist—should have done his homework. He did not. (To be fair, Higgins did speak with Alley Cat Allies; but “equal time” is a poor substitute for accuracy.) And the consequences of his carelessly scattering a few figures around a column devoted to gardening are considerable: the seeds of proofiness!

Maybe readers don’t expect Higgins to know (or care, even) how many free-roaming cats there are in the U.S. Or how much time pet cats spend outdoors. Still, though, Higgins is an avid gardener—he, of all people, should be able to recognize bullshit.

*     *     *

SPECIAL THANKS to Louise Holton, founder of Alley Cat Rescue, who brought the Washington Post article (along with countless other news items over the past few months!) to my attention. She and Maggie Funkhouser, ACR’s Director of Communications and Public Relations, have become invaluable resources.

Literature Cited
1. Higgins, A., Bird lovers see roaming cats as a major threat to many species, in The Washington Post. 2010: Washington, DC. http://www.washingtonpost.com/wp-dyn/content/article/2010/09/28/AR2010092803999.html

2. Seife, C., Proofiness: The Dark Arts of Mathematical Deception. 2010: Viking Adult.

3. 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.

4. Winter, L., “Popoki and Hawai’i’s Native Birds.” ‘Elepaio: Journal of the Hawaii Audubon Society. 2003. 63(6).

5. Hatley, P.J., Feral Cat Colonies in Florida: The Fur and the Feathers Are Flying. 2003, University of Florida Conservation Clinic: Gainsville, FL.

Inside Job

Results from the American Pet Products Association’s 2009­­–2010 National Pet Owners Survey suggest that cats in this country are spending more time indoors than ever before. Although the proportion of owners keeping their cats inside at night has remained relatively steady since 1998 (at approximately 66%), their has been a 14% increase in daytime confinement (from 56% to 64%) over the same period. [1]

Indoor&Outdoor Access-APPA

It must be noted that owners were asked where they usually kept their cat(s), thereby raising some doubts about the accuracy of their responses. (There are actually two issues here: first is the level of truthfulness—did owners, intentionally or not, provide accurate information? But there is also the obvious ambiguity surrounding the term usually.) Nevertheless, these results correspond reasonably well with those of two earlier surveys: one commissioned by the American Bird Conservancy (ABC) in 1997, [2] the other conducted by Clancy et al. in 2001 [3] (the only other surveys I’ve found that investigated this issue specifically).

The ABC’s study (in which 250 cat owners participated in a telephone survey) indicated that “35% keep their cats indoors all of the time,” while “31% keep them indoors mostly with some outside access.” [2]

The 2001 survey included 168 cat owners, each of whom was part of the Feline Health Study, conducted at the Foster Hospital for Small Animals, Cummings School of Veterinary Medicine, Tufts University. Sixty percent of these cats were “strictly indoor cats,” while 40% “had some level of outdoor access.” [3] Probing further, Clancy et al. discovered that nearly half of the cats with outdoor access were outside for two or fewer hours a day. And 29% of them were outdoors for less than an hour each day. [3]

Considering the differences in sampling (most notably the fact that participants in the 2001 survey were all clients of a veterinary hospital, whereas APPA survey results for 2000 indicate that 27% of cat owners did not visit the vet in the previous 12 months), and the inherent uncertainty surrounding the terms mostly, usually, and some, the results of these three surveys are remarkably similar.

Counting Cats
Such findings are critical for developing accurate estimates of the number of birds killed by cats (assuming a reasonable level of accuracy is achievable, given the complexity of the issue). Simply put, cats that don’t go outside can’t kill birds.

Recognizing this, some researchers have inflated their figures for cats allowed outdoors. [4–6]

Dauphiné and Cooper, [6] for instance, cite the APPA’s 2007–2008 survey when referring to the number of owned cats in the U.S., but either ignored or overlooked its findings about confinement: 63% of owners reported that they kept their cat(s) indoors during the day, 70% during the night. (It’s also possible that the authors consulted only the APPA’s online summary, which probably didn’t include this information.)

By contrast, Dauphiné and Cooper claim that 65% of pet cats “are free-ranging outdoor cats for at least some portion of the day,” [6] citing not the APPA survey, but Linda Winter’s 2004 paper, “Trap-neuter-release programs: the reality and the impacts” (which can be downloaded here). Indeed, Winter, the former director of the ABC’s Cats Indoors! campaign, had suggested as much—misrepresenting the findings of a study commissioned by her own organization:

“A 1997 nationwide random telephone survey indicated that 66% of cat owners let their cats outdoors some or all of the time.” [7]

Double the proportion of cats allowed outdoors, and—just like that—the number of birds killed by pet cats doubles too. (Dauphiné and Cooper actually go much further, employing some grossly inflated predation rates as well.)

Counting Birds
Of course, such estimates do not necessarily relate directly to population impacts. The predation may be largely compensatory, for example; and there are source-sink dynamics to be considered as well.

Nevertheless, researchers persist—more often, it seems, in pursuit of staggering, media-friendly figures than a better understanding of what’s actually going on (e.g., Dauphiné and Cooper’s bumper-sticker-worthy “one billion birds”). As a result, the scientific literature is plagued with some rather spectacular failures where predation numbers are concerned (e.g., The Wisconsin Study, Christopher Lepczyk’s dissertation, Carol Fiore’s thesis, etc.).

*     *     *

The surprising level of agreement among the three “outdoor access” studies provides researchers a rare opportunity to agree among themselves. Which, in turn, could move us closer to an honest debate of the larger issues—arguing about which action is most appropriate, for instance, rather than about whose numbers are most valid.

Despite how results of these surveys have been—as recently as last year—overlooked, ignored, and misrepresented, I remain cautiously optimistic. As Patronek has suggested, “predation of songbirds tends to be noticed because it takes place during the day.” [8] It’s time predation research received the same kind of visibility. Sunlight, after all, is said to be the best of disinfectants.

Note: There is a an amendment to this post here.

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

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

3. 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.

4. 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

5. 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.

6. 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.

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

8. 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.

Red Herrings, White Lies, and Blue Birds

A pair of Eastern Bluebirds in Michigan, USA. Photo courtesy Wikimedia Commons and Sandysphotos2009

As I sift through my growing collection of studies, news stories, press releases, and anything else relevant to the free-roaming cats/TNR debate, it’s not unusual for me to be diverted by a seemingly minor item—a claim, interpretation, or reference that simply doesn’t sit right with me. (The subsequent investigation of which helps explains the almost alarming rate at which the collection continues to grow.) Sometimes these diversions snowball, taking on a momentum all their own and, ultimately, evolve into their own blog post(s). Others remain largely in the background—overshadowed by more pressing issues—but are too compelling to be ignored for long.

This was the case with some comments Lepczyk et al. made about “two species of conservation concern” in their 2003 paper “Landowners and Cat Predation Across Rural-to-Urban Landscapes,” [1] which I discussed some time ago. The study, in which surveys were distributed across three southeastern Michigan landscapes (rural, suburban, and urban) corresponding to established breeding bird survey (BBS) routes, asked respondents to recall the number of birds their cat(s) brought home April through August 2000. Among the authors’ conclusions:

“The fact that both Eastern Bluebirds and Ruby-throated Hummingbirds were listed [among those killed by cats] indicates that some species of concern are being captured.” [1]

Eastern Bluebirds
Of the 137 birds (representing an estimated 23 species) identified by landowners (approximately one-third were not identified), six (4.4%) were Eastern Bluebirds. What piqued my curiosity was not the tally itself, but the authors’ subsequent comment that “the location of the three landscapes represents an area of Michigan where the species is rarest and not always identified on bird atlas survey routes.” [1]

Wait a minute. The people conducting bird counts along these routes rarely, if ever, locate Eastern Bluebirds—but the cats that live nearby managed to find at least six of them over the course of just five months? Where Lepczyk et al. see reason for concern, I see reason for (cautious) optimism: There are, as the cats demonstrated, more Eastern Bluebirds than we thought!

Just to be clear: I don’t mean to dismiss conservation concerns for uncommon or rare species. Nor am I criticizing the efforts of the many dedicated professionals and volunteers responsible for bird counts. But in trying to reconcile these seemingly contradictory findings, one can’t help but wonder: How many birds are there, really?

To find out, I began by consulting The Atlas of Breeding Birds of Michigan, the very source Lepczyk et al. cite, where, sure enough, a map indicates that no more than two Eastern Bluebirds are typically found along survey routes in the southeastern part of the state. Indeed, even in the most abundant parts of Michigan, no more than four of this species are reported. [2] But this atlas was published in 1991, more than 10 years prior to Lepczyk’s dissertation research.

To look at more recent data—and long-term trends—I referred to the website for the North American Breeding Bird Survey, where the survey is explained this way:

“The BBS is a large-scale survey of North American birds. It is a roadside survey, primarily covering the continental United States and southern Canada, although survey routes have recently been initiated in Alaska and northern Mexico. The BBS was started in 1966, and the over 3,500 routes are surveyed in June by experienced birders.”

The BBS site allows visitors to investigate trends (spanning roughly 40 years) by species, region, and survey route. What I found for Eastern Bluebirds along the three routes employed by Lepczyk et al. (49053, 49167, and 49168) was rather surprising. In all three cases, the abundance of Eastern Bluebirds trends upward—in some cases dramatically.

Eastern Bluebird BBS Data
BBS Data: Eastern Bluebirds for Three Michigan Routes (adapted from North American Breeding Bird Survey website)

Route 49053 is of particular interest for a couple reasons. First of all, it is the only one of the three for which data going back to the BBS’s inception is available, allowing the best long-term perspective. Secondly, the increase in Eastern Bluebird abundance corresponds almost perfectly to publication of The Atlas of Breeding Birds of Michigan. Between 1991 and 2000 (the year Lepczyk was conducting his research), the picture changed considerably.

The other two routes—to a lesser degree, certainly—also exhibit notable increases. Why Lepczyk referred to the Atlas rather than to this more recent data is unclear.

Bird Counts
It’s important to recognize that bird counts are not intended to quantify, in any absolute sense, the number of birds in a particular area, a point made clear on the BBS website:

“The survey produces an index of relative abundance rather than a complete count of breeding bird populations.”

In addition, the use of roadside surveys has been criticized for its potential biases. Roadside habitats may not reflect—and/or may change at rates different from—an area’s overall habitat, for example. [3] Also, a number of factors affect an observer’s ability to detect or identify a particular species. Some—sight, hearing, and training, and even clothing color, for example—are associated with the surveyors, while others (e.g., plumage, body size, coloration, and density) have to do with the birds being surveyed. [4] Rosenstock et al. suggest that such impediments raise serious questions about index counts in general:

“Measures of relative abundance derived from index counts… represent an uncertain, confounded combination of detectability and density. Given these weaknesses, index counts should not be expected to provide reliable information or a valid basis for inference.” [4]

All of which makes weighing the six Eastern Bluebirds in Lepczyk’s study against those detected along the survey routes a dodgy proposition. (Dodgier still is the more expansive claim made by Longcore et al. that Lepczyk’s work is “evidence indicat[ing] that cats can play an important role in fluctuations of bird populations.” [5])

House Sparrows
To reiterate, I’m not discounting conservation concerns for rare or protected species (the Eastern Bluebird, it should be noted—and Lepczyk et al. acknowledge—is neither “extremely rare” nor a “species of state or national concern.” [1]) I’m merely pointing out some of the complexities involved in trying to connect predation levels of one species to population levels of another.

Which brings me back to The Atlas of Breeding Birds of Michigan, where I discovered an interesting twist in this story. The Eastern Bluebird, it seems, probably peaked in Michigan during the late 1800s.

“A gradual decline occurred in the early 1900s as the House Sparrow advanced, and favorite nesting places such as wooden fenceposts and old apple orchards were eliminated.” [2]

As it turns out, House Sparrows were at the top of the list in Lepczyk’s study, making up 38% of the identified species of birds taken by cats.

“Although the species group of Sparrows could not be broken down into species, it is very likely that the dominant species observed was the House Sparrow (Passer domesitcus). Sparrows were also the most commonly observed depredated species found in England and Australia [6, 7].” [1]

While I’m not prepared to suggest that the cats’ heavy predation of House Sparrows is responsible for the increasing numbers of Eastern Bluebirds, perhaps it’s not as far-fetched as it sounds. Similar assertions have been made regarding the role of cats in the larger ecosystem (though such claims are rarely in defense of the cats).

Nature’s interconnectedness rarely makes for punchy sound bites or bumper sticker aphorisms. Then, too, such complex relationships are often overlooked, ignored, or dismissed simply because they don’t fit cleanly into one’s argument.

Literature Cited
1. 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.

2. Brewer, R., McPeek, G.A., and Adams, R.J., The atlas of breeding birds of Michigan. 1991, East Lansing, MI: Michigan State University Press.

3. Keller, C.M.E. and Scallan, J.T., “Potential Roadside Biases Due to Habitat Changes along Breeding Bird Survey Routes.” The Condor. 1999. 101(1): p. 50-57.

4. Rosenstock, S.S., et al., “Landbird Counting Techniques: Current Practices and an Alternative.” The Auk. 2002. 119(1): p. 46-53.

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.

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

7. 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.

False Confessions

Whether the latest iteration of reality TV— Animal Planet’s Confessions: Animal Hoarding—is more education, entertainment, or exploitation is a matter of debate. But it’s a safe bet that by streaming “an unflinchingly honest look at a human condition that affects people and animals” into living rooms across the country, a problem too rarely acknowledged (not to mention taken seriously) is now receiving unprecedented attention.

Even if I were a cable subscriber, though, I don’t think I’d be tuning in. Although I was nowhere near the “front lines” of the Great Kitty Rescue, I’ve seen and heard plenty where animal hoarding is concerned. But in reading about Confessions, I was reminded of some remarks included in a comment published earlier this year in Conservation Biology. There, Christopher 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 compared TNR to animal hoarding:

“The animal welfare community opposes ‘cat hoarding,’ whereby people care for more pets than they can adequately support, because it is considered inhumane. Trap-neuter-return is essentially cat hoarding without walls. Considering that most communities have laws banning animal hoarding, we should consider the same standard for outdoor cats as those that are in a person’s home.” [1]

This strikes me as almost desperate—the latest volley in the kitchen-sink/something-for-everybody approach taken by some TNR opponents. Nevertheless, the analogy—however incongruous—is not new. In 2004, David Jessup made essentially the same comparison:

“Some people are compelled to own and care for excessive numbers of cats. This psychological illness is referred to as ‘collectors psychosis.’ How is the person who must save 25 to 30 cats in their home different from the person who sees themselves [sic] as the savior of 25 to 30 cats in a park? Some ‘cat people’ may be ‘collectors,’ and it is possible that TNR is enabling and supporting some people who need psychologic counseling and assistance.” [2]

Jessup doesn’t burden himself or his audience with even the slightest support for his assertions; his claims are as much conjecture as anything else, his question largely rhetorical. Five years later, Dauphiné and Cooper revisited Jessup’s query, but—despite a handful of references—do no better in terms of its resolution:

“In many cases, the characteristics and behavior of people involved in TNR are suggestive of the psychiatric disorders described in problematic animal hoarding [3]. When presented with alternatives to TNR, such as enclosed sanctuaries, no-kill shelters, and traditional animal control, many such people can be “fiercely protective, retaliatory, and uncooperative,” [4] and will subject public officials and other citizens opposing TNR to harassment and threats [5, 6].” [7]

Animal Hoarding
Dauphiné and Cooper’s argument presupposes that enough is known both about “people involved in TNR” and “the psychiatric disorders described in problematic animal hoarding” for a valid comparison to be made. In fact, very little is known about either one. Randy Frost, whose 2000 article the authors cite, begins by noting, “almost no psychiatric literature exists on this topic.” [3] A year earlier, Gary Patronek (a collaborator of Frost’s, whose work Frost cites throughout his paper) observed: “Unlike the hoarding of inanimate objects, which may be linked with a variety of psychiatric conditions, animal hoarding has not yet been linked with any specific disorder.” [8]

Nevertheless, both Patronek and Frost describe—based on some of the earliest research on the subject—some common characteristics of, and explanatory models for animal hoarding. And provide this definition:

“someone who accumulates a large number of animals; fails to provide minimal standards of nutrition, sanitation and veterinary care; and fails to act on the deteriorating condition of the animals (including disease, starvation and even death) or the environment (severe overcrowding, extremely unsanitary conditions), or the negative effect of the collection on their own health and well-being and on that of other household members.” [8]

This seems to have been the framework for the definition adopted by the Hoarding of Animals Research Consortium (with which Patronek and Frost were involved), which places greater emphasis on two key elements: denial, and accumulation and control:

  • Having more than the typical number of companion animals;
  • Failing to provide even minimal standards of nutrition, sanitation, shelter, and veterinary care, with this neglect often resulting in illness and death from starvation, spread of infectious disease, and untreated injury or medical condition;
  • Denial of the inability to provide this minimum care and the impact of that failure on the animals, the household, and human occupants of the dwelling;
  • Persistence, despite this failure, in accumulating and controlling animals.

“Saving” 25 or 30 cats, then—whether in one’s home or in the park—does not constitute animal hoarding. As Patronek pointed out during a recent interview on NPR’s Radio Times, “numbers alone don’t define hoarding… you’ve got to have these functional deficits and denial, in combination with the numbers.”

Opponents of TNR (and of free-roaming cats in general) will likely seize upon that second point, arguing that feral cat colonies—by definition—lack adequate care. But the very fact that these cats are part of a TNR program means they’ve been evaluated by veterinary professionals, requiring a concerted effort—sometimes bordering on the heroic—on the part of the trappers and caregivers involved. Some programs perform vaccinations (that this is not standard practice, is, admittedly, a controversial issue); at a minimum, cats deemed too sick to be returned are euthanized.

A 1999 survey of survey of “101 individuals or couples who cared for 132 colonies of free-roaming cats in north central Florida” illustrates the importance caregivers place on health:

“More than a third of the caretakers reported that they had provided some kind of veterinary care (not including being neutered at the TNR clinic) for the cats in the past or would provide veterinary care if it was necessary in the future. This type of care included booster vaccinations, parasite control, antibiotic treatment, ear medication, veterinary examinations, and emergency treatment.” [9]

In addition, 96% provided food, and 75% provided shelter. It’s important to note, too, that these numbers are conservative relative to the care received by the cats, in that (1) some caregivers were responsible for multiple cats, and (2) respondents to the survey were not necessarily the individuals who provided food, shelter, and so forth.

Such findings are certainly consistent with my own experience. The TNR networks I’m tapped into (mostly by way of e-mail or online bulletin boards) are typically buzzing with requests from, and recommendations to, caregivers committed to maintaining and improving the health of feral cat colonies.

On the other hand, it’s not clear from Dauphiné and Cooper’s paper that their reference to animal hoarding has anything to do with the behavior’s defining characteristics at all. More than anything else, the authors seem to be suggesting that resistance to TNR “alternatives” constitutes some psychiatric disorder—a possible reference to animal hoarders’ “reluctance to remove any animals, even when adequate homes were available.” [3]

Alternatives to TNR
Respectable sanctuaries, as I’ve already discussed, are few and far between, and typically at operating at capacity. In any case, such environments are not in the best interest of unsocialized cats. No-kill shelters, too, are scarce, and—recognizing realities Dauphiné and Cooper (and veterinarian Christine Storts, whose letter they cite) overlook or ignore—generally endorse TNR as their feral cat management approach. [10]

And as for “traditional animal control,” that’s nothing more than a rather cowardly euphemism for trap-and-kill.

What about the harassment and threats? Here, Dauphiné and Cooper cite Paul Barrows’ 2004 article “Professional, Ethical, and Legal Dilemmas of Trap-Neuter-Release,” and Pamela Jo Hatley’s 2004 paper, “Will Feral Cats Silence Spring in Your Town?” “During the past several years,” writes Barrows:

“as debate regarding abandoned and feral cats has become more heated, concerns have emerged regarding the extent to which some activists will go to promote their cause. Those supporting trap and removal of abandoned and feral cats, rather than TNR, have reported verbal abuse, personal threats, disruption of public forums, and interference with the conduction of their businesses.” [5]

Dauphiné and Cooper buy into Barrows’ account without bothering to check out his source (actually, these two make a shameful habit of such shortcuts throughout their paper, thereby raising questions about their numerous assertions, and, more problematically, their capabilities and integrity as researchers). In fact, Barrows cites a 2002 Wall Street Journal story in which exactly one of “those supporting trap and removal”—Frank Spiecker, of Garden State Pest Management—was interviewed:

“…property managers, fearing health complaints or lawsuits, hire Mr. Spiecker to trap and remove stray cats… Cat jobs have gotten him screamed at, threatened and jostled. His truck has been jumped on and pounded, his traps run over, and his trapped cats freed… To cat lovers, he abets feline mass murder, since most of the cats he traps end up dead.” [11]

All of which seems remarkably flimsy for describing and condemning—as Dauphiné and Cooper do—the behaviors of “many such people.” Until it’s compared to the even flimsier “evidence” provided by Hatley:

“Many citizens and public officials have voiced concerns about the public health issues and wildlife issues involved in hoarding large numbers of cats in the wild. Some who have resisted the extreme efforts by proponents of TNR and cat colonies have been subjected to verbal abuse and threats.” [6]

Dodgy research practices aside, the notion that one’s preference for TNR over “enclosed sanctuaries, no-kill shelters, and traditional animal control” is indicative of some psychiatric disorder remains a mighty hard sell. Dauphiné and Cooper’s so-called alternatives are simply not—in a very literal sense—viable options.

*     *     *

To compare TNR to animal hoarding betrays either a profound lack of knowledge about either one, or a desperate attempt to taint the former by association with the latter. I suspect that, like the most despicable political strategists, Jessup, Dauphiné and Cooper, and Lepczyk et al., threw it out there just to see if it would stick—the connection they’re attempting to make certainly has nothing to do with science.

I’ve a friend who jokes that the only thing feral cats aren’t being blamed for these days is climate change. Well, not yet, anyhow.

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

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. Frost, R., “People Who Hoard Animals.” Psychiatric Times. 2000. 17(4).

4. Storts, C.M., “Discussion on TNR programs continue (letter).” Journal of the American Veterinary Medical Association. 2003. 222: p. 711–712.

5. 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.

6. Hatley, P.J. (2004) Will Feral Cats Silence Spring in Your Town? www.pamelajohatley.com/Articles/ABA.pdf Accessed August 8, 2010.

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. 2009. p. 205–219.

8. Patronek, G.J., “Hoarding of animals: An under-recognized public health problem in a difficult-to-study population.” Public Health Reports. 1999. 114(1): p. 81–87.

9. 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.

10. Winograd, N.J., Redemption: The myth of pet overpopulation and the no kill revolution in America. 2007: Almaden Books.

11. Sterba, J.P., Tooth and Claw: Kill Kitty?, in Wall Street Journal. 2002: New York. p. A.1

Out-Sciencing the Scientists

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

Hutchins goes on to write:

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

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

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

Dear Michael,

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

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

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

In your post, you write:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Peter J. Wolf
www.voxfelina.com

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The Work Speaks—Part 7: Leaky Sink

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 6 of this series, I critiqued Christopher Lepczyk’s paper Landowners and cat predation across rural-to-urban landscapes, published in 2003. Here, I’m going to examine two studies conducted by Philip J. Baker and various collaborators.

The Studies
In the first study, Baker et al. distributed questionnaires to 3,494 households across a 4.2 km2 area of northwest Bristol (UK), and used responses to estimate cat ownership and predation levels (via prey returned home). [2] This work served as a pilot study for the subsequent study.

The second study, conducted August 2005–July 2006, was also conducted in Bristol. Added to the original 4.2 km2 site were nine 1 km2 sites. The researchers used very similar sampling methods, but, based on results of their pilot study, had somewhat more specific objectives:

  1. To quantify cat density
  2. To quantify the various species of birds killed by cats.
  3. To estimate the impact of cat predation by species and site.
  4. To determine whether the predation observed was compensatory or additive. [3]

Sources and Sinks
Among the authors’ conclusions from the pilot study was that, at least for three of the ten bird species surveyed:

“…it is possible that cat predation was significantly affecting levels of recruitment and creating a dispersal sink for more productive neighboring areas.” [2]

Dispersal sinks or habitat sinks, are patches of low-quality habitat that are unable to sustain a population of a particular species were it not for immigration from higher quality habitat patches—called sources—nearby. So, what Baker et al. are suggesting is that predation by cats may be extensive enough to deplete populations of certain bird species at their study site, such that at least some of the birds observed there were immigrants from nearby habitat.

But the authors also point out that, “despite occurring at very high densities, the summed effects on prey populations appeared unlikely to affect population size for the majority of prey species.” [2] And even for House sparrows, which were among the three species of concern (and, apparently, in decline throughout the UK’s urban areas), Baker et al. note that their “numbers appear to be stable in Bristol as a whole.”

So, is the area a habitat sink or not?

A cursory look at the theory and empirical measurement of source-sink dynamics reveals great complexity. Variations across time and geography must be taken into account—the ebb and flow of local populations might easily be overlooked or misunderstood by applying a short time horizon (i.e., 12 months) and arbitrary boundaries (i.e., those that define the study site). Annual rainfall, for example, can dramatically influence yearly population levels on a local scale. And it’s been shown that source-sink dynamics can occur over distances of 60–80 km. [4] In fact, the determination of sinks and sources in the field can be problematic enough that sources sometimes appear to be sinks and vice-versa. [5]

Given the complex nature of source-sink dynamics, the suggestion by Baker et al. that cat predation may be creating a habitat sink seems rather premature. Such assertions—despite the requisite disclaimers (the authors note only that “it is possible”)—tend to attract attention and gain traction. Longcore et al., for example, cited the pilot study in their 2009 essay, “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return.” [6]

Of greater interest to me, though, are the assumptions Baker et al. used to estimate the impact of cat predation.

Counting Cats and Counting Birds
In both studies, the authors quantified the impact of cat predation on bird populations by comparing different levels of predation with different bird densities. Their maximum impacts, for example, assumed that all cats were hunters—despite the fact that 51–74% of the cats included in the two studies brought home no prey at all—and that bird productivity was zero (i.e., no young birds survive to adulthood). As the authors admit:

“This was clearly not realistic, as the estimated maximum numbers of birds killed typically exceeded breeding density and productivity combined, such that the prey populations studied would probably have gone extinct rapidly at a local level or acted as a major sink for birds immigrating from neighbouring areas.” [3]

But how realistic are their other estimates?

A detailed examination of a single species at a one site (taken from the second study, for which such information is available) illustrates some flaws. I looked at House sparrows for the 1 km2 site designated as ST5277. Here, 18 participants reported that their 22 cats returned a total of 30 prey items, nine of which were birds (two of them “unidentified”). Of the birds returned home, two were House sparrows.

When it comes to estimating impacts, though, Baker et al. use figures of 332–1,245 House sparrows killed by the cats of ST5277. The maximum, we already know, is “not realistic,” but even the minimum seems awfully high. So, where are these birds coming from?

To start with, two adjustments have to be made to the original predation figure. First, the two unidentified birds are “distributed” across the categories of bird species that were identified. Then, we have to account for participant drop-out; not all of the 22 cats were surveyed for the entire year of the study. Now we’re up to an average of 8.7 House sparrows brought home annually by the cats at this site.

But of course there are more than 22 cats at ST5277. Baker et al. estimate that there are 314 of them (although we know very little about the factors that affect their hunting ability and success—for example, their access to the outdoors, age, etc.). We also know that only seven of the 22 cats included in the study brought home prey. In other words, 32% of the cats surveyed were documented hunters. Based on these numbers, then, we can estimate the yearly predation rate of House sparrows at ST5277 to be roughly 125—well short of the minimum proposed by Baker et al. (and just a quarter of their intermediate rate).

There are some minor differences between their method for estimating predation rates and mine. For the most part, though, the “missing” sparrows can be found in the authors’ use of a correction factor (3.3) proposed by Kays and DeWan to account for prey killed but not returned home. [7] Undoubtedly, cats fail to bring home all the prey they catch (though they also undoubtedly bring home prey they didn’t kill), but there is good reason to doubt Kays and DeWan’s “correction.” Among the flaws in their analysis were small, dissimilar samples of cats, and a failure to account for highly skewed data sets.

So, even setting aside the complexities of source-sink dynamics, these inflated predation rates, combined with the fact that “the estimates of breeding density presented in this manuscript should be regarded as minima,” [3] raise serious doubts about whether the site is in fact a habitat sink (or, if so, to what extent).

Compensatory and Additive Predation
As I’ve discussed previously, even accurately predicted levels of predation can be deceptive. There’s compensatory predation (in which prey would have died even in the absence of a particular predator, due to illness, starvation, other predators, etc.) and additive predation (in which healthy prey are killed). It’s the difference between, as Beckerman et al. put it, the “doomed surplus hypothesis” and the “hapless survivor hypothesis.” [8]

When it comes to relating predation to population levels, it’s critical to understand the difference, and know the extent to which each type is occurring.

To get at this critical issue, Baker et al. compared the physical attributes (e.g., muscle mass score, mean fat score, etc.) of 86 birds killed by collisions (e.g., with cars, windows, etc.) to those of 48 birds killed by cats. Although the authors point out, “the relationship between body mass and quality (i.e., likelihood of long-term survival and therefore reproductive potential) in passerines is complex,” they nevertheless conclude that the birds killed by cats “were likely to have had poor long-term survival prospects.” [3] (An earlier study comparing spleen mass arrived at essentially the same conclusion: that birds killed by cats “often have a poor health status.” [9])

Still, Baker et al. express caution about their findings:

“The distinction between compensatory and additive mortality does, however, become increasingly redundant as the number of birds killed in a given area increases: where large numbers of prey are killed, predators would probably be killing a combination of individuals with poor and good long-term survival chances. The predation rates estimated in this study would suggest that this was likely to have been the case for some species on some sites.”

But their inflated predation rates and low estimates of breeding density combine to diminish the apparent level of compensatory predation. Were these estimates adjusted to better reflect the conditions at the site, the “redundancy” the authors refer to would be reduced considerably.

*     *     *

It’s not clear why Longcore et al. cited the pilot study their essay, but left out any mention of the much larger subsequent study. Perhaps it was just a matter of timing—“Cats About Town” was published in August of 2008, while “Critical Assessment” was published in August of 2009. A year is not much time in the world of scientific journals, and it’s possible that the two manuscripts more or less crossed in the mail. On the other hand, the pilot study fits more neatly into the argument put forward by Longcore et al.—an argument that doesn’t even recognize the distinction between compensatory and additive predation.

Of course, Baker et al. did themselves no favors, either. By using inflated predation rates—the result of some peculiar, unjustified assumptions—they virtually buried the most important findings of their study.

References
1. 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.

2. 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.

3. 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.

4. Tittler, R., Fahrig, L., and Villard, M.-A., “Evidence of Large-Scale Source-Sink Dynamics and Long-Distance Dispersal among Wood Thrush Populations.” Ecology. 2006. 87(12): p. 3029-3036.

5. Runge, J.P., Runge, M.C., and Nichols, J.D., “The Role of Local Populations within a Landscape Context: Defining and Classifying Sources and Sinks.” The American Naturalist. 2006. 167(6): p. 925-938.

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. 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.

8. Beckerman, A.P., Boots, M., and Gaston, K.J., “Urban bird declines and the fear of cats.” Animal Conservation. 2007. 10(3): p. 320-325.

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

Learning Your ABC

According to an AP story posted on MSNBC, city officials in Barre, VT, are considering a leash law for cats—effectively prohibiting them from roaming. Such stories tend to vary only in their specifics; quotes from embattled citizens, and feline references that are more dismissive than clever (e.g., in Barre, the debate “sparked a hissing match”) are pretty much a given. And, more often than not, there’s a statement from the American Bird Conservancy (ABC) about the threat free-roaming cats pose to wildlife. This story was no exception:

“Scientists estimate that free-roaming cats kill hundreds of millions of birds, small mammals, reptiles and amphibians each year,” the Virginia-based American Bird Conservancy, which runs a “Cats Indoors!” campaign, says on its website. “Cat predation is an added stress to wildlife populations already struggling to survive habitat loss, pollution, pesticides, and other human impacts.”

Although I don’t know anybody who would argue with ABC’s second point, that first one bears closer inspection.

I discussed a similar claim by ABC’s Senior Policy Advisor, Steve Holmer, in one of my first Vox Felina posts. In January, 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.”

Late last year, an article in Audubon Magazine had published nearly identical figures, citing ABC as its source. [1]

The feral cat estimate comes from a conference paper written by Nico Dauphiné and Robert J. Cooper, available for download via the ABC website. When I pressed Holmer about the authors’ “creative accounting,” he backed off, assuring me that ABC’s materials “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 never received a reply, though, to my inquiries about that “more than one million birds each day” claim. Such incidents are, unfortunately, not uncommon; when it comes to assertions about cat predation and its impact on wildlife, ABC has a rich—and rather shameful—history.

Cats Indoors!
Holmer’s comment to the L.A. Times is just one example of ABC’s concerted effort to use the (largely unquestioning) media in getting their message out. Last year, at a news conference about the “The U.S. State of the Birds” report, ABC’s Darin Schroeder told the press, “education is urgently needed to make the public aware of the toll of pet cats.” Which is precisely what ABC’s Cats Indoors! campaign—launched in 1997—aims to do.

The question is, what kind of education is the public getting from ABC?

  • A 1997 report by ABC claimed, “extensive studies of the feeding habits of domestic, free-roaming cats… show that approximately… 20 to 30 percent [of their diet] are birds.” [cited in 2] In fact, as Ellen Perry Berkeley points out in her book, TNR Past Present and Future: A history of the trap-neuter-return movement, the 20–30% figure was not based on “extensive studies” at all. [2]ABC’s Linda Winter, writing to Berkeley, cited just three sources. Two of them—the now-classic “English village” study by Peter Churcher and John Lawton, and the “Wisconsin Study” by John Coleman and Stanley Temple—have been widely discredited. [3–5] And the third, Mike Fitzgerald’s contribution to “Diet of domestic cats and their impact on prey populations,” [6] was misinterpreted and/or misrepresented by ABC. (As Berkeley notes, Fitzgerald’s data “would put birds, as a portion of the diet of cats, at roughly 7 to 10.5 percent—nowhere near the ‘20 to 30 percent’ figures unleashed on the unscientific public by ABC!” [2])
  • Winter, director of Cats Indoors! (assuming she’s still at ABC; their website does not list her among the staff), and ABC president George Fenwick were among those thanked “for helpful and constructive reviews” in the Acknowledgements section of Christopher Lepczyk’s 2003 paper, “Landowners and cat predation across rural-to-urban landscapes.” As I detailed in my previous post, Lepczyk’s study is flawed both in terms of its method and analysis, and his predation estimates are highly inflated as a result. The fact that Winter and Fenwick were involved in such as study—at any level—raises questions about ABC’s credibility (and its possible influence on research outcomes).
  • In 2004, Winter misrepresented the results of a survey commissioned by ABC. In “Trap-neuter-release programs: The reality and the impacts,” published in the Journal of the American Veterinary Medical Association, she suggested, “66% of cat owners let their cats outdoors some or all of the time.” [7]In fact, the survey indicated that “35% keep their cats indoors all of the time” and “31% keep them indoors mostly with some outside access.” [9] While Winter’s claim isn’t exactly untrue, it certainly paints a very different picture: rather than one-third, two-thirds of cats are free-roaming. Which, apparently, is exactly how Dauphiné and Cooper read it, combining this with an inflated figure for the number of feral cats to come up with their estimate of “117–157 million free-ranging cats in the United States.” [8] (It’s difficult not to see a certain coziness here: Dauphiné and Cooper citing Winter’s “interpretation” of her own survey results, and Holmer’s reliance on Dauphiné and Cooper’s conference paper.
  • To this day, ABC refers to the highly-criticized Wisconsin Study in its brochure Domestic Cat Predation on Birds and Other Wildlife: “Researchers… estimated that rural free-roaming cats kill at least 7.8 million and perhaps as many as 217 million birds a year in Wisconsin. Suburban and urban cats add to that toll.” [9]And, despite Berkeley’s efforts to untangle their erroneous dietary figures, ABC has backed off only slightly: “In an ongoing, but unpublished, study of cat prey items including stomach contents, scat analysis, observations of kills, and prey remains, birds were 19.6% of 1,976 prey captured by 78 outdoor cats (Temple, S.A, Univ. of WI, personal communication, 1/22/04).”

    [Note: Download Laurie D. Goldstein’s Addressing the Wisconsin Study for a comprehensive critique of this work.]

*     *     *

Don’t get me wrong; I’m all for keeping cats indoors. But what about the feral and stray cats out there—what happens to them? Here, ABC doesn’t seem to have a lot of answers. At least not any they’re willing to be up-front about.

In fact, by disseminating information that is at best misleading—and often, just plain wrong—ABC is doing whatever it can to shape policy in such a way that many of these cats will, one way or another, be killed. Intentional or not, Cats Indoors! has become a kind of Trojan horse for those determined to eliminate all free-roaming cats. Attention can very quickly shift from the impact of a proposed leash law, for example, to the “cat problem” in general.

Although it’s packaged as sound advice for cat owners, the Cats Indoors! campaign has probably had a far greater (deadly) impact on unowned cats than on pet cats.

References
1. Williams, T., Felines Fatale, in Audubon Magazine. 2009, National Audubon Society: New York, NY. http://www.audubonmagazine.org/incite/incite0909.html

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

3. Goldstein, L.D., O’Keefe, C.L., and Bickel, H.L. Addressing “The Wisconsin Study”. 2003.  http://www.straypetadvocacy.org/html/wisconsin_study.html.

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

5. 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.

6. 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. p. 123–147.

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

8. 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.

9. ABC, Domestic Cat Predation on Birds and Other Wildlife. n.d., American Bird Conservancy: The Plains, VA. www.abcbirds.org/abcprograms/policy/cats/materials/predation.pdf