Complaining of the impacts of free-roaming cats on wildlife and the environment, along with a range of public health threats, dozens of veterinarians in Hillsborough County, Florida, have banded together to fight TNR. Evidence suggests, however, that their real concern has nothing to do with the community, native wildlife, or, indeed, with cats. What the Hillsborough Animal Health Foundation is most interested in protecting, it seems, is the business interests of its members.
This was Take Your Cat to the Vet Week, a time “to raise awareness of the fact that cats need an annual veterinarian examination just as much as dogs,” according to Feline Pine, the litter manufacturer responsible for the occasion’s creation. In Hillsborough County, Florida, however, it was a time for many in the veterinary community to reiterate their opposition to TNR.
“We love cats!” Don Thompson assured me earlier this week via e-mail. “Any person who argues that vets don’t love animals is being foolish.” But, just like David Aycock, chief animal control officer for Pompano Beach, Thompson’s love has its limits—feral cats need not apply.
Thompson’s not a vet himself, but an attorney. He, along with his veterinarian wife, Katie, operate the Veterinary Center at Fishhawk, and he’s also head of the Hillsborough Animal Health Foundation, whose members are, according to the HAHF website, “gravely concerned about Trap-Neuter-Return (TNR).”
To explain the “trouble with trap-neuter-re(abandon!),” HAHF has posted excerpts from, and links to, numerous articles—along with a good deal of commentary—on its extensive website. This, we’re told, allows visitors “to ‘drill down’ into the subject.”
I imagine very few will be taking HAHF up on the offer, though—persuaded by what appears to be overwhelming evidence. But their Potemkin Village approach is an insult to the intelligence of visitors (on either side of the issue) and HAHF members. In fact, drilling down into the subject reveals a host of flaws, both in the studies and reports referenced, and in HAHF’s interpretation of the findings therein.
Their assumption, I suppose, is that nobody will notice.
I won’t address every study and report mentioned on the HAHF website, and I won’t go into too many details—but instead include links to relevant blog posts in which I’ve addressed the topic previously. The categories correspond to those used by HAHF.
TNR Not Working
“When TNR first began,” argues HAHF, “the goal was to reduce the feral cat population humanely.”
“While this goal was admirable, time and scientific studies show that TNR doesn’t work for population control. Perhaps more importantly now, feral cat advocates define ‘success’ without including decreases in numbers, focusing instead on the health of the cats themselves… In a large area like Hillsborough County, TNR will not work, even if there were no other health concerns. Study after study documents that TNR, due to the ability of feral cats to avoid trapping and due to their remarkable ability to breed, is not effective in terms of population control.”
As I explain on TNR Fact Sheet No. 1, several credible studies have documented TNR’s potential for decreasing the number of cats in a particular location. [1–3] Furthermore, the suggestion that lethal control methods would be more effective—implicit in HAHF’s criticism of TNR—simply doesn’t hold up to scrutiny. Indeed, the data from Hillsborough County Animal Services are sobering: “From 1996 to 2008… the county’s public shelter euthanized about 82 percent (over 306,000) of its animal intake. In calendar year 2005, 73 percent of dogs entering the shelter were euthanized, as were 92 percent of cats.” 
Among the studies HAHF cites to support their assertion:
Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return (2009)
This, of course, is the often-cited paper by Travis Longcore that became the focus of one of my first blog posts. As I explain in Reassessment: A Closer Look at “Critical Assessment of Claims Regarding Management of Feral Cats by Trap-Neuter-Return” (PDF), careful scrutiny of the authors’ claims reveals glaring omissions, blatant misrepresentations, and obvious bias.
Analysis of the Impact of Trap-Neuter-Return Programs on Populations of Feral Cats (2005)
“The reality is,” argues HAHF, “TNR doesn’t reduce the population of feral cats.” The evidence? Population modeling based on large-scale TNR programs in Alachua County, FL (11,822 cats), and San Diego County, CA (14,452 cats). As HAHF explains, “the authors, including Dr. Julie Levy, a noted TNR advocate, write, ‘In both counties, results of analyses did not indicate a consistent reduction in per capita growth, the population multiplier, or the proportion of female cats that were pregnant.’”
But those same authors also wrote this: “Retrapping success for feral cats probably was underestimated because cats were marked after neutering by removal of a small distal portion of the pinna and ear-tipped cats usually were released from cages without counting.” 
In other words, the trappers involved didn’t necessarily understand that they needed to return every cat caught to the clinic. Because ear-tipped cats were generally released—standard operating procedure for TNR—the cats were never counted among the “successes.” Nor were any ear-tipped cats that charmed their way into homes (a more common occurrence than most folks think). The problem here was not with the effectiveness of TNR, but with the methodology used to measure it (as Levy acknowledged to me via e-mail).
An Evaluation of Feral Cat Management Options Using a Decision Analysis Network (2010)
“This paper,” claims HAHF, “demonstrates the ineffectiveness of TVNR,* and shows that contrary to advocates [sic] claim, TVNR is the most expensive alternative that currently exists for management of feral cats.”
In fact, that’s not at all what Kerrie Anne Loyd (well known for her recent KittyCam work—see below) and Jayna DeVore found (despite their peculiar choice of research method). “Our model,” they explain in the paper’s abstract, “predicts that Trap-Neuter-Release strategies would be optimal management decisions for small local populations of less than fifty cats while Trap-Euthanize would be the optimal management decision for populations greater than 50 cats.” 
Legal and Ethical Issues
“Simply put, TNR is not legal!” complains HAHF. But the Hillsborough County Board of County Commissioners sees things rather differently. In December of last year, the BOCC passed a resolution (R11-135) that reads, in part:
“The Board of County Commissioners… recognizes TNR programs that both comply with federal, state, and local laws by complying with guidelines established by the American Society for the Prevention of Cruelty to Animals and the Humane Society of the United States for TNR, as another means to reduce the community cat population in addition to trapping and euthanizing.”
HAHF argues that “the Federal Migratory Bird Treaty and the Endangered Species Act negatively implicate TVNR and creates the possibilitity [sic] of legal action against veterinarians engaging in TVNR,” and that “the primary veterinarian medical malpractice carrier will not provide insurance coverage for illegal activies [sic].”
“As a result, the legal risk is substantial for veterinarians participating in TVNR. When coupled with every other piece of scientific fact, the veterinary community of Hillsborough County must reject the notion of county sanctioned TVNR.”
I suppose it’s possible that the many veterinarians across the country—hundreds or thousands of them—involved in TNR are flouting both federal law and the counsel of their malpractice insurers. But where are the court cases? Given the great controversy surrounding the issue—and the ease with which it makes headlines—it’s difficult to imagine such a case going unnoticed.
Not surprisingly, the two papers cited by HAHF make similar claims—also without the mention of a single legal case involving TNR.
Professional, Ethical, and Legal Dilemmas of Trap-Neuter-Release (2004)
“Dr. [Paul] Barrows makes clear that it is unwise to overturn long standing public health policies relating to feral cats,” observes HAHF, “and that the veterinary medical malpractice insurer has determined that many aspects of TVNR are illegal and cannot be insured against.”
But Barrows undermines his own credibility when he endorses, for example, The Wildlife Society, the American Bird Conservancy, PETA, and National Audubon Society, arguing that “veterinarians should carefully review the well-considered and strong foundations upon which these organizations formulated their policies on free-roaming cats and TNR.” 
I agree that careful review is in order—but, as I’ve demonstrated repeatedly, such scrutiny reveals precious little in the way of “strong foundations.”
Like HAHF, Barrows is especially concerned about rabies—in particular, the “minimization of rabies as a risk by some proponents of TNR.” Citing a 1994 CDC report,  he describes a New Hampshire case in which “exposures to a kitten of unknown origin that was subsequently diagnosed with rabies led to the treatment of an estimated 665 individuals and expenses of more than $1.5 million for investigation, laboratory testing, and rabies immunoglobulin and vaccines.” 
But, as a 1996 article in The American Journal of Public Health points out, the incident was truly extraordinary in its scale: “the previously reported record for treatment resulting from exposures to a single rabid animal was 70 persons; that treatment cost $105,790 and was associated with a rabid dog in California.”  Citing such an extreme example, Barrows does little to shed any light on the true risk of rabies exposure posed by free-roaming cats in general, and TNR in particular.
The article also provides some valuable context Barrows overlooks or ignores. The kitten, as it turns out, was not outdoors at all, but for sale in a pet store—and the potential exposures spanned 35 days: “Based on the epidemiologic investigation by health officials, exposures to the rabid cat and to other cats in the store from September 19 to October 23, 1994, were considered potentially communicable.” 
Contrary to what Barrows implies, the real take-away has nothing to do with free-roaming cats, and everything to do with public health policy.
“Details of the exposure histories suggest that many individuals received postexposure treatment as the result of contacts with animals that were unlikely to transmit rabies. Experience has shown that nonbite exposures, such as scratches or abrasions, warrant postexposure treatment only under special circumstances.
The fact that 41 percent of the 375 treated individuals only picked up or petted a pet-store kitten suggests that the CDC Immunization Practices Advisory Committee’s recommendations for administering postexposure treatment were not rigorously applied. The inability of physicians to obtain detailed exposure histories from very young patients and the media hysteria surrounding the incident of the rabid pet-store kitten presumably resulted in liberal treatment recommendations.” 
(I suspect the irony here is lost on HAHF: by contributing to the “media hysteria,” members may actually impede the effective implementation of the very public health policies they claim to endorse.)
In his discussion of “ethical dilemmas,” Barrows encourages supporters of TNR to “mov[e] beyond impassioned debate.”
“…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.” 
To back up his rather sweeping statement, though, 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 (by a reporter whose sourcing is, it turns out, as “selective” as Barrows’):
“…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.” 
Ethical dilemmas, indeed.
Feral Cat Colonies in Florida: The Fur and the Feathers Are Flying (2003)
It’s no surprise that HAHF would embrace the work of Pamela Jo Hatley, whose 2003 report to the U.S. Fish and Wildlife Service (written while Hatley was a law student, and part of the University of Florida Conservation Clinic) is often cited by TNR opponents. (Interestingly, Hatley and nine co-authors—including Dauphiné and Marra—chose not to cite it in their 2010 letter to Conservation Biology,  turning instead to former director of the ABC’s Cats Indoors! program, Linda Winter’s misrepresentation of Hatley’s work.  For a detailed explanation, please see my April 16 post.)
According to HAHF, Feral Cat Colonies in Florida “considers all laws from federal statutes to local ordinances, and is widely cited by other journal articles as the authoritative source for legal considerations.” And Hatley, we’re told, “is one of the national experts on legal issues as they pertain to feral cats.”
Hatley argues that “existing laws could be effective in discouraging the use of TNR and cat colonies as a way to attempt to manage the free-roaming cat population in this country.”  She’s particularly interested in the Endangered Species Act (which, in her words, “has been described as the ‘pit bull’ of environmental laws” ) and the Migratory Bird Treaty Act.
Citing three cases having nothing to do with cats (or any other predators), Hatley argues that such “cases raise the question of whether a person violates the MBTA when that person releases a cat into the wild, and that cat kills a migratory bird.”
“If an accidental chemical leak, aerial application of a pesticide, or failure to install equipment to protect birds from power lines can result in a person being charged with violation of the MBTA, why not release of cats into the environment? It does not take a great stretch of the imagination to conclude that a cat’s impact on birds can be as lethal as any poison.” 
To my knowledge, however, no legal cases have put Hatley’s arguments to the test in the nine years since she submitted her report to USFWS.
Wildlife Predation Issues
“Cats are,” according to HAHF, “recognized as a widespread and serious threat to the integrity of native wildlife populations and natural ecosystems.”
“Wildlife biologists have clearly documented the impact of feral cats on the environment, and feral cat run-ins with wildlife include competition, predation, and disease transmission… feral cats have caused substantial harm to species as diverse as sea otters and marsh rabbits… nothing short of removal from the ecosystem will stop the harm to native wildlife. Cats belong indoors, or contained outdoors; not loose and preying on endangered species outdoors.”
The message would perhaps have greater impact if the accompanying photo—intended, I assume, to depict a menacing predator—were of a cat doing something other than yawning. (Yes, these are veterinary professionals.)
Among the studies included on the HAHF site:
Impacts of Free-ranging Domestic Cats (Felis catus) on birds in the United States: A review of recent research with conservation and management recommendations (2009)
HAHF cites the 2009 paper co-authored by former Smithsonian researcher Nico Dauphiné (who resigned after being found guilty of attempted animal cruelty last year, after rat poison was found in cat food outside her apartment building) as evidence of “the incredible impact of free ranging cats on the bird populations of the U.S.” Among the many flaws in “Impacts of Free-ranging Domestic Cats” was the authors’ estimate of “117 to 157 million exotic predators,” which was based on David Jessup’s inflated (and, not surprisingly, unattributed) “estimate” of “60 to 100 million feral and abandoned cats.”  Accounting for pet cats, the authors ignore or overlook the multiple large-scale surveys demonstrating that about two-thirds of cats are indoor-only, [15–17] thus further inflating their “estimate.”
HAHF also quotes the paper’s mention of “declines and extinctions of birds worldwide.”  But, as I’ve pointed out previously, only eight of the 33 bird extinctions Dauphiné and Cooper refer to (presumably justifying their claim that cats are “one of the most important causes of bird extinctions worldwide”) were attributed to cats exclusively.  Of those, just two are actually extinct: the Stephens Island Wren and the Macquarie Island kakariki (red-crowned parakeet).
The Welfare of Feral Cats and Wildlife (2004)
Citing intake figures from the Lindsay Wildlife Museum (which claims, naturally without any supporting evidence: “Cats kill over four million birds in the U. S. every day”) for roughly the first nine months of 2003, Jessup complains that “24 percent (1,050) of birds, 12 percent (143) of mammals, and 15 percent (11) of reptiles were presented because of cat-related injuries or conditions.” 
“These animals were brought in alive and do not include those that died or were not found… [This] includes 36 [bird] species, many of which are songbirds or locally rare, sensitive, or migratory species; all are supposed to be protected by law from illegal take.” 
As Animal People’s Merritt Clifton pointed out in a 2003 story, the wildlife rehabilitation perspective simply doesn’t provide one with information sufficient to infer much about population dynamics. Birds of the kind Jessup mentioned “are among the few who are rescued by humans, typically because the humans intervene to break off the cat attack.” 
“That changes the predator/prey dynamic. The cat has no opportunity to finish the kill because of the human intervention. Otherwise, the injuries… would impair flight, and would lead to a cat meal. These are not failures of predation, but successes, interrupted, comparable to what happens when a hyena chases a cheetah off a half-dead gazelle and appropriates the meal for himself.
The true failures of predation rise into the air and get away unscathed. The… hypothesis that large numbers of birds are dying in the wild of cat-inflicted injuries and infections is simply not supported by evidence, whereas roadkilled birds and the remains of birds who collide with windows, transmission towers, and power lines, as well as those who succumb to pesticides, have all been collected and studied by researchers in bucketloads.” 
“KittyCam” Reveals High Levels of Wildlife Being Killed by Outdoor Cats (2012)
I suppose it’s no surprise that HAHF would cite Loyd’s overhyped “KittyCam” study as evidence of the impact of cats on wildlife. As I pointed out earlier this month, though, the predation Loyd documented was notable for how little there was—especially where birds were concerned (though, of course, ABC and The Wildlife Society painted a very different picture in their joint media release).
Loyd compiled 2,000 hours of video, from 55 cats—and documented just five birds mortalities. And, more than likely, none of the birds was rare. (No doubt ABC and TWS would have made a point of it were that not the case.) It’s also likely that the birds killed by cats were unhealthy or injured.  and 
As Loyd herself conceded in an April interview with CBS Atlanta, “Cats aren’t as bad as biologists thought.” 
Population Demography of Gray Catbirds in the Suburban Matrix: Sources, Sinks and Domestic Cats (2011)
Peter Marra’s research in the suburbs of Washington, DC, (in which Dauphiné was later involved), observes HAHF, “establishes the predation of stray and feral cats on the (rather ironically) gray catbird. The study shows a predation rate by the cat that is rather appalling.”
As I explained in March of last year, the breakdown goes like this: of the 69 juvenile catbirds monitored over the course of the study, 42 died—33 of them due to predation. Cats (and there’s no reason to think these weren’t pets—Marra, in fact, says at least one of them was) were the cause of six of the 33 mortalities (though Marra tacks on three more, based, I argue, on some dubious claims). The other predators: black rat snake (1 predatory event), red-shouldered hawk: (1), rat or chipmunk (7), and “Avian predation” (1). The remaining 14 mortalities,” write Marra and his co-authors, “could not be assigned to a specific predator.” 
What’s appalling here is HAHF’s use of this small-scale—often misrepresented (mostly by Marra himself)—study to suggest that predation by cats is of any significance in this context.
Public Health Issues
“The public health trouble with TNR,” argues HAHF, “is that even vaccinated stray cats are still carriers of many significant infectious diseases and are able to transmit those diseases to other animals and humans.”
“Although the scientific literature is clear that indoor, owned cats properly cared for are little risk, the literature is equally clear that unowned feral and stray cats are a signficant [sic] risk! Worse, a large burden of the risk lies against our precious children! Anything that increases the risk to our kids is unacceptable.”
This same message was echoed in an e-mail dated August 13, sent by the Veterinary Center at Fishhawk in response to a recent protest:
“Of interest, the extremists are very angry that we are ‘using scare tactics’ by sending an email with the subject line ‘our children are at risk’—while ignoring the fact that 600–700 children in the U.S. go blind every year as a result of roundworms, with too many of those coming from sand boxes. Our local pediatricians report seeing hookworms in children on a weekly basis in Hillsborough County…”
In my research, I’ve found nothing to support these claims. Documenting the late-2010 hookworm outbreak in Miami Beach, The Miami Herald reported: “…an investigation has confirmed seven hookworm infections contracted between July and September. Eight more are under investigation….”  But in Hillsborough County, pediatricians are seeing cases weekly? Were this the case, I would expect the topic to warrant some coverage in the papers, along with at least a mention in the 2010/2011 Hillsborough County Community Health Profile report (PDF). Yet no such evidence exists.
Similarly, I’ve found no support for the HAHF claim about 600–700 children going blind as a result of toxocariasis.
I attempted to contact the Hillsborough County Health Department via e-mail, inquiring about the prevalence of both roundworms and hookworms, but have yet to receive a reply.
Cat Welfare Issues
“The life of a stray, or feral, cat is tough,” argues HAHF. “This hardly constitutes animal welfare, and as veterinarians we are determined to end this needless suffering. Our domesticated buddies do not deserve to die behind the dumpster, they deserve to find homes and be brought in off the mean streets.”
OK, but what about the vast majority of street cats who aren’t good adoption candidates? “Nothing short of removal from the ecosystem,” I suppose. Tens of thousands of them in Hillsborough County alone.
How’s that for ending the needless suffering?
To drive the point home, HAHF posted a few graphic photos “of feral cats recently presented to veterinary hospitals around Hillsborough County this year (2012).” But for every gruesome photo HAHF has, I have many more—of happy, healthy street cats.
While it’s generally acknowledged that more than half of kittens born “in the wild” don’t survive into adulthood,  kittens born into managed colonies (a fairly common occurrence early on) are often adopted by caretakers or homes found through local rescue organizations. Take away TNR—as HAHF proposes—and the chances of those “domesticated buddies” making their way indoors become awfully slim.
And caretakers often report of cats living long, healthy lives in managed colonies. More than half of the 23 cats living continuously on the University of Central Florida campus during an 11-year observation period were estimated to be 6.8 years old or older.  And a 2012 nationwide survey conducted by Alley Cat Rescue revealed similar longevity: one quarter of TNR organizations responding to the survey have colony cats in the 6–8 year range; 35 percent in the 9–12 year range, and 14 percent reported caring for cats 13 years of age or older. 
Obviously, no caretaker wants to see harm come to the cats in their care. But TNR is—as I think everybody acknowledges—a compromise.
Caretakers and TNR supporters largely seem to acknowledge the trade-offs but nevertheless reject lethal control methods. As a 2007 Harris Interactive survey commissioned by Alley Cat Allies (PDF) revealed, such methods are out of step with public opinion. Indeed, 81 percent of the “nationally representative sample of 1,205 adults” agreed that “leaving a stray cat outside to live out his life is more humane than having the cat caught and killed.” 
None of which matters, I suppose, to those who think life outdoors is simply too risky—that preemptive killing (on an unprecedented scale) is ethical—a moral imperative, even. And I don’t image anything I can say is going to change that. But bringing all the science into it—the rigorous and the indefensible alike—is, at best, disingenuous.
But as I’ll discuss in Part 4 and Part 5, the real issue here doesn’t seem to have much to do with cats at all.
• • •
*TVNR, an acronym for trap-vaccinate-neuter-return, seems to be the invention of HAHF; others use TNVR.
• Part 2: Rabies cases in Hillsborough County and across the state
• Part 3: Toxoplasmosis prevalence
• Part 4: Hillsborough County Animal Services: Past, Present, and Future
• Part 5: Would the real HAHF please stand up?
1. 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
2. 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
3. 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
4. Hamilton, F.E., “Leading and Organizing Social Change for Companion Animals.” Anthrozoos. 2010. 23(3): p. 277–292. http://www.ingentaconnect.com/content/berg/anthroz/2010/00000023/00000003/art00006
5. 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. http://avmajournals.avma.org/doi/abs/10.2460/javma.2005.227.1775
6. 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/
7. 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. http://avmajournals.avma.org/doi/abs/10.2460/javma.2004.225.1365
8. n.a., “Mass Treatment of Humans Exposed to Rabies—New Hampshire, 1994.” Morbidity and Mortality Weekly Report. 1995. 44(26): p. 484–486. http://wonder.cdc.gov/wonder/prevguid/m0038110/m0038110.asp
9. Noah, D.L., et al., “Mass human exposure to rabies in New Hampshire: exposures, treatment, and cost.” American Journal of Public Health. 1996. 86(8): p. 1149–51.
10. Sterba, J.P. (2002, October 11). Tooth and Claw: Kill Kitty? Wall Street Journal, p. A.1.
11. 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
12. Winter, L., “Popoki and Hawai’i’s Native Birds.” ‘Elepaio: Journal of the Hawaii Audubon Society. 2003. 63(6).
13. Hatley, P.J., Feral Cat Colonies in Florida: The Fur and the Feathers Are Flying. 2003, University of Florida Conservation Clinic: Gainesville, FL. http://www.animallaw.info/articles/arus18jlanduseenvtll441.htm
14. 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
15. Clancy, E.A., Moore, A.S., and Bertone, E.R., “Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats.” Journal of the American Veterinary Medical Association. 2003. 222(11): p. 1541-1545. http://avmajournals.avma.org/doi/abs/10.2460/javma.2003.222.1541
16. 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
17. APPA, 2009–2010 APPA National Pet Owners Survey. 2009, American Pet Products Association: Greenwich, CT. http://www.americanpetproducts.org/pubs_survey.asp
18. 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
19. Ziswiler, V., Extinct and Vanishing Species: A biology of extinction and survival, ed. F. Bunnell and P. Bunnell. 1967, New York: Springer-Verlag.
20. Clifton, M. (2003, June). Where cats belong—and where they don’t. Animal People, from http://www.animalpeoplenews.org/03/6/wherecatsBelong6.03.html
21. 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/
22. 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
23. Paluska, M. (2012) Kitty cameras show Athens cats on the prowl. http://www.cbsatlanta.com/story/17711012/kitty-cameras-show-athens-cats-on-the-prowl
24. 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
25. Smiley, D. (2010, November 24). Miami Beach deals with hookworm fears. The Miami Herald,
26. n.a. (2012) Alley Cat Rescue’s National Feral Cat Survey. PR Newswire http://www.prnewswire.com/news-releases/alley-cat-rescues-national-feral-cat-survey-157263395.html
27. Chu, K. and Anderson, W.M., Law & Policy Brief: U.S. Public Opinion on Humane Treatment of Stray Cats. 2007, Alley Cat Allies: Bethesda (MD). http://www.alleycat.org/document.doc?id=61