Anti-TNR Letter to Tulsa Animal Welfare Commission and City Councilors

Dear Tulsa Animal Welfare Commission and City Councilors.

Many Tulsa citizens are not in favor of Trap/Neuter/Release (TNR) and ‘community’ feral cats colonies, but that does not mean that we are against providing cats with good welfare and humane options. We believe that we have a responsibility to cats as domestic animals to do our best to get them into loving homes where they will be cared for, receive medical care and kept safe. Our overall goals are the same as other interested parties in that we want strong spay/neuter (S/N) programs - programs that have consequences for those Tulsans that choose to ignore these ordinances. We want feral cats to be trapped, S/N, and vaccinated, but, if not adopted, to be sent to contained cat sanctuaries, not released to the streets to live in a feral state. Those animals that cannot be adopted or confined should be considered for humane euthanasia. We are trying to be realistic in that we do not expect there to ever be Zero feral cats but we do not see dumping cats on the street and feeding them as a feasible, humane or responsible policy. In the Tulsa Animal Welfare Commission survey, over 50% of respondents were against the establishment of feral cat colonies, via the use of TNR. We’d like to illustrate some of our points on what feral cats experience and what their feeding can cause within our community.

  1. Feral cats do not experience good welfare. They die of disease, trauma, and predation. We do not believe that being hit by a car (Figure 1) or killed by a predator (Figure 2) are humane ways of trying to control the overpopulation of feral cats.

Figure 1. Brookside area of Tulsa, cat hit and killed by car.

Figure 2. Outdoor roaming cat captured by coyote.

  1. We want cats to be treated like other domestic animal pets, i.e.. dogs, and not allowed to roam, so that owned cats are S/N, vaccinated for rabies and have a license /tag just like dogs in the City of Tulsa (COT). This requires enforcement, such that for owned cats that are trapped in the City there is a fine just like when your dog is picked up running loose. Identification can require a microchip and or collar with tag. 40 years ago, it was common to allow pet dogs to roam, S/N was not that common for dogs and it took education and enforcement of fines to control feral dogs. Now it is widely accepted that feral dogs are a threat to the public safety and public health; feeding them is not allowed. People who own dogs assume that they will be confined, S/N, licensed and tagged. This can happen for cats as well, and for the benefit of the cats, their owners and the public. The local environment and wildlife will benefit as well. This public education takes time and effort. Pet ordinance rules can be included in every COT utility bill, along with billboards and PSAs about which pets must be S/N and licensed, as well as that violations will lead to progressive fines.

  2. Outdoor feeding of cats should be outlawed via city ordinance, due to its potential public health issues, attraction of wildlife and the further promotion of feral cat recruitment by way of the dumping of unwanted cats by owners. The cats themselves shed parasites such as Toxoplasma gondii, round worms and hookworms in their feces. These parasites can cause various diseases in humans. Toxoplasma infection has serious ramifications for human health and many people are infected unknowingly. Symptoms may only appear later when the person is immunocompromised or it can cause birth defects or miscarriage if women become infected while pregnant. The amount of dirt under one’s fingernail from the garden, if that soil is contaminated with Toxoplasma cysts from cat feces, is enough to cause infection.

Outdoor feeding of feral cats promotes the artificial concentration of wildlife such as skunks, raccoons, rats and opossums that share food with feral cats. In doing so, they share their feces, saliva and possibly blood (in a USA equivalent of a Wuhan ‘Wet Market’ situation) where parasites, viruses and bacteria can be transferred much more readily among animals and then people.

Outdoor feeding promotes the concentration of cats to an area, which also draws predators in that feed upon those cats, especially foxes and coyotes. These predators do not stay where there is not enough food. This artificial concentration of a food sources (both cat food and the cats themselves) brings predators into areas that otherwise might not encourage or support their presence. There will always be urban wildlife in some population, but feeding them increases their sustainable population. Along with skunks and raccoons, both foxes and coyotes can become infected with Rabies. They also spread Leptospirosis, parasites and Canine Distemper virus.

Figures 4 A & B are camera trap images of a TNR feeding station in another state being used by raccoons, where the food is placed in covered cat litter boxes to protect it from the weather.

A. Raccoons are common urban wildlife in Tulsa and one of the reservoir hosts of the Rabies virus; they also spread Leptospirosis, Canine distemper, roundworms, fleas, and ticks. Striped skunks are also common visitors to such free food sources; the striped skunk is the primary vector of Rabies in the state of Oklahoma. Note high concentration of these animals sustained by nutritious high protein cat food.

B. Cats and raccoons together sharing food at feeding station. Excellent opportunity to share pathogens. Note 3 raccoons to 1 cat in this instance.

Night vision camera trap photo of coyote visiting TNR feeding station. It has options - eat the cat food or a cat, if available.   Feral cats are also a threat to birds and other wildlife. Cats can cause local extinctions of wildlife and have contributed to 33 global extinctions. In the United States, a peer-reviewed study by scientists from the Smithsonian and the U.S. Fish & Wildlife Service estimated that approximately 2.4 billion birds (Figure 3) and 12.3 billion mammals are killed in the United States by cats every year. While both owned and feral cats contribute, feral cats are responsible for over two-thirds of these bird deaths and nearly 90 percent of mammal deaths.

Figure 3. Feral cat killing a bird

Closing points:

Feral cats do not experience good welfare and die violent but unseen deaths by cars, other cats, diseases and predators. Humane euthanasia is a witnessed controlled death. No-kill cat colonies trade that humane death for unwitnessed cruel and often violent death unseen in the bushes, drains and roads of our community. We are NOT advocating for euthanizing all feral cats. We agree that strong and continuous efforts at trapping, S/N and aggressive adoption efforts are needed to save those cats that can make good pets. What we are advocating for is humane treatment that can include euthanasia for those that are not adoptable, or can’t be placed in enclosed sanctuaries. We feel that roaming pets and S/N ordinances have not been enforced regularly or with real consequences for Tulsa citizens to take them seriously. Good educational opportunities abound in materials the COT already uses to communicate with its citizens; utility bill notices, billboards and websites. For those Tulsa citizens who do not want feral cats on their property, feral cat excrement and urine in their gardens, yards and businesses, what recourse do they have? Will the COT just tell them too bad, feral cats are not our problem? Fed up residents will take matters into their own hands at the ballot box and on their property to alleviate the situation, again cats will suffer. The idea of emptying the shelters and releasing feral cats just kicks the can down the road and the citizens of Tulsa and the cats themselves will pay the price.

Please see extensive scientific references below because science does matter with regard to feral cat management, not just our emotions. This information was compiled through an exhaustive study recently done by another city with regard to its feral cat dilemma. There is a great deal of research that has been done with regard to feral cats, their impacts, their control and the efficacy of various methods of that control. It overwhelmingly shows that TNR is NOT an effective means of controlling feral cat populations, despite its good intentions.

Sincerely,

Tulsa Audubon Society
(Representing over 800 Tulsa area members)

Kay Backues, DVM
Tulsa Resident, Voter District 4

Zach Poland
Tulsa Resident, Voter District 9


SCIENTIFIC EXCERPTS BY TOPIC OF CONCERN

These are excerpted from City of Saratoga Springs, Utah City Council Meeting’s Research on the Science and claims of TNR, October 1, 2019. Note: they decided against having TNR in their community.

TNR DOES NOT REDUCE THE POPULATION OF FERAL CATS IN THE COMMUNITY

“Overwhelmingly, the scientific literature indicates that Trap, Neuter, Release (TNR) programs fail to reduce feral cat populations and negatively impact people and wildlife.”

“Data contradicted the assertion that managed cat colonies decline in size over time and suggested that trap, neuter, and release programs are not an effective method to help control the population of unwanted feral and free-roaming cats.”

American Bird Conservancy (2019). The evidence against trap, neuter, release. www.abcbirds.org
“TNR was not effective at reducing free roaming cat numbers…”

Schmidt, P. M., Swannack, T. M., Lopez, R. P., Slater, M. R., (2009). Evaluation of euthanasia and trap-neuter-return programs in managing free-roaming cat populations. Wildlife Research 36, 117-125.
“A 1 year study of TNR programs…revealed that well-fed cat colonies encouraged illegal abandonment…the arrival of new cats prevented the reduction of the colonies…”

Levy, J. K., Crawford, P. C., (2004). Humane strategies for controlling feral cat populations. JAVMA 225, 1354-1360.
“Our analysis indicated that any population-level effects were minimal…which indicated ongoing population growth…”
“…no plausible combinations of life history variables would likely allow for TNR to succeed in reducing population size…”
“Although causes of loss from the population included euthanasia of sick cats, adoption, and deaths (often vehicular trauma), increases in population were attributable to immigration…”

Foley, P., Foley, J. E., Levy, J. K., Paik, T., (2005) Analysis of the impact of trap-neuter-return programs on the populations of feral cats. JAVMA 227, 1775-1781.
“…virtually no information exists to support the contention that neutering is an effective long-term method for controlling freeroaming cat populations.”
“Immigration or abandonment of new cats may be a frequent event, and free-roaming cats do not appear to have sufficient territorial activity to prevent new arrivals from permanently joining colonies. These new arrivals could substantially limit the success of TNR…”

Levy, J. k., Gale, D. W., Gale, L. A., (2003) Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population. JAVMA 222, 42-46.
“Overall, we did not find any significant differences in population counts across years.”
“…we counted more than twice as many cats in 2012 as we did in 2011.”
“…while we did find a statistically significant increase in the proportion of sterilized individuals…this increase was not enough to expect any decline in population numbers.”

Kilgour, R. J., Magle, S. B., Slater, M., Christian, A., Weiss, E., DiTullio, M., (2017) Estimating free-roaming cat populations and the effects of a one year Trap-Neuter-Return management effort in a highly urban area. Urban Ecosyst 20, 207-216
“Neither study reduced cat numbers.”
“Reducing cat survival (by increasing euthanasia rates) would likely have a greater effect on cat population growth than reducing fecundity (by increasing sterilization rates).”
“A 50% increase in annual euthanasia rates would likely result in a population decline of 10% per annum; whereas a 75% increase in annual sterilization rates would likely result in an increasing population.”
“Trap-euthanize strategies have proven effective at reducing cat populations…In contrast, TNR programs alone have never been shown to stabilize a feral cat population in the scientific literature.”

Gotsis, T., (2014) Feral cats: Do trap-neuter-return programs work? NSW Parliamentary Research Service 18/2014, 1-19
“…numerous scientific studies have found that trap-neuter-release operations fail to reduce populations within a colony.”

Bies, L., (2019) Feral cats: impacts of an invasive species. The Wildlife Society Fact Sheet, wildlife.org
“It cannot be stated definitively that the total number of cats on campus decreased…”

Hughes, K. L., Slater, M. R., (2002) Implementation of a feral cat management program on a university campus. Journal of Applied Welfare Science 5(1), 15-28
“Free-roaming cat populations have a high intrinsic growth rate, and euthanasia is estimated to be more effective at reducing cat populations than trap-neuter-return programs.”
“Thus, TNR programs are not likely to convert increasing cat populations into declining populations or even stable populations…”

Andersen, M. C., Martin, B. J., Roemer, G. W., (2004) Use of matrix population models to estimate the efficacy of euthanasia versus trap-neuter-return for management of free-roaming cats. JAVMA 225, 1871-1876
“The model suggested that TNR…will not lead to long-term reduction in the numbers of cats because colonies can re-establish due to immigration.”

Stoskopf, M., Nutter, F. (2004) Analyzing approaches to feral cat management – one size does not fit all. JAVMA 225, 1361-1364
“…all these (TNR) efforts…are a waste of money, time, and energy.”

Natoli, E., et. al. (2006) Management of feral domestic cats in the urban environment of Rome (Italy). Preventative Veterinary Medicine 77, 180-185
“Stray dogs, cats, and ferrets should be removed from the community…”
“Stray and feral cats serve as a significant source of rabies exposure risk.”

Brown, C. M., Slavinski, S., Ettestad, P., Sidwa, T. J., Sorhage, F. E., (2016) National Association of Public Health Veterinarians Compendium of animal rabies prevention and control. JAVMA 248, 505-517
“…free-roaming cats are not native to any environment in the United States. Many scientific studies report that non-lethal (TNR) programs do not reduce the numbers of feral cats in the environment.”

Frey, N., (2015) Stray cats in your neighborhood. Utah State University Extension, Featured Animal September 2015
“A study of TNR implemented countywide in San Diego showed that feral cat populations had not decreased after 10 years, and a similar result was found after 7 years in Alachua County, Florida, where feral cat populations increased (Foley et al. 2005). ”
“Two colonies subject to TNR in Florida were tracked for over a year and population size of both colonies increased owing to the influx of new cats dumped at the highly visible sites (Castillo & Clarke 2003).”

Longcore, T., Rich, C., Sullivan, L. M., (2009) Critical assessment of claims regarding management of feral cats by trap-neuter-return. Conservation Biology 23(4), 887-894
“TNR programs require consistent funding and commitment and cannot be expected to lead to eradication as long as the environment is hospitable to cats and cats are available for immigration into the area.”

Kustritz, M.V.R., (2011) Managing feral cat colonies. DVM Proceedings May 01, 2011
“In a survey of 101 cat feeders…the total surveyed cat population was reportedly 920 before participation in TNR and 678 after TNR. However, the total number of cats (n=920) minus deaths (151), disappearances (149), and adoptions (238) and plus births (498) and immigrations (103) equals 983, not 678.”

Winter, L., (2004) Trap-neuter-release programs: the reality and the impacts. JAVMA 225, 1369-1376.
“The practice of trapping, neutering, and then re-releasing cats into managed cat colonies does not effectively control cat populations and their adverse impacts on wildlife and should be opposed…”
“The most effective and humane method of dealing with feral cats is to remove them through trapping followed by adoption or euthanasia”
“…eradication is the only real answer, however unpleasant…”
“…studies and practical experience with cat colonies have shown that they are the wrong solution to cat overpopulation.”

Wallace, G., Ellis, J., (2003) Impacts of feral and free-ranging domestic cats on wildlife in Florida.
Issue Assessment- Florida Fish and Wildlife Conservation Commission. FERAL CATS SPREAD DISEASE TO HUMANS “Unowned free-roaming cats pose important threats to human health. Zoonotic concerns include the rabies virus, Toxoplasma gondii, Bartonella species, Toxocara cati, Microsporum canis, Cryptosporidium species, Campylobacter species, Yersinia pestis, Cheyletiella species and Francisella tularensis.”

Folfer, W. R., Lovelace, K., Robertson, S., Rose, C., (2013) American Association of Feline Practitioners: Freeroaming, abandoned and feral cats. Journal of Feline Medicine and Surgery, 821-822
“As a rabies vector, cats pose a disproportionate risk for potential human exposures…”
“A study of 67 counties in Pennsylvania found that 44% of postexposure prophylaxis administration was due to cats, most of which (82%) were feral, stray, or unowned.”
“Many other potential zoonotic and cat-specific diseases are harbored in feral cat populations in addition to rabies. Among these are bartonellosis, toxoplasmosis, plague, endo-and ectoparasites, feline immunodeficiency (FIV), feline leukemia virus (FeLV), and rickettsial diseases.”
“Group feeding of cats by colony caretakers puts cats at a greater risk for contracting diseases whose transmission is augmented by increased animal density and contact rates among cats…Group feeding also increases risk for contracting rabies and other wildlife diseases by enabling greater contact along the interface between cat colonies and wildlife reservoirs…Feeding sites that attract raccoons, skunks, and foxes are particularly dangerous because these species are rabies reservoirs in the U.S.”
“TNVR does not adequately meet feral cat population control needs that public health and animal welfare necessitate.”
“One recent study, which modeled costs and benefits for TNVR as compared to trap and euthanize programs, found that in all scenarios trap and euthanize programs were cheaper to conduct and had a higher economic benefit.”
“TNVR…should not be endorsed as an effective approach…for mitigating health concerns related to feral cat colonies.”

Roebling, A. D., Johnson, D., Blanton, J. D., Levin, M., Slate, D., Fenwick, G., Rupprecht, C. E., (2014) Rabies prevention management of cats in context of trap, neuter, vaccinate, release programs. Zoonoses Public Health 61(4), 290-296.
“Domestic cats shed 3 to 349 million T gondii oocysts 3 to 5 days after consuming infected animal tissues…”
“Annual fecal deposition…by owned cats in the 3 communities was estimated to be 76.4 tons…Feral cats…could be contributing 29 .5 tons of feces to environment per year…”
“T gondii oocysts…can remain viable for more than a year in the soil. Contaminated soil is an important source of infection for humans, herbivores, rodents, and birds.”

Dabritz, H. A., Atwill, R., Gardner, I. A., Miller, M. A., Conrad, P. A., (2006) Outdoor fecal deposition by freeroaming cats and attitudes of cat owners and nonowners toward stray pets, wildlife, and water pollution. JAVMA 229, 74-81
“Rabies is a disease of great significance in all species, including humans. In the most recently published survey of rabies surveillance in the United States, rabid animals were identified in 49 states…cats represented…nearly 4 times that reported for dogs.”
“In one survey of feral cats in Italy, two of eight rabid cats were from known feral cat colonies that were managed by human caregivers.”
“Toxoplasma gondii always is present in feral cat colonies…”
“One study estimated that in a single community, the amount of feces deposited outdoors by the 2046 feral cats living there every year was about 29.5 tons. A study tracking sources of E. coli in storm sewers feeding rivers and streams demonstrated that the highest percentage from any one source came from cats.”

Kustritz, M.V.R., (2011) Managing feral cat colonies. DVM Proceedings May 01, 2011
“Of the more common zoonotic diseases spread by free-roaming cats, rabies is the most worrisome…the disease is diagnosed in cats more often than in any other domestic animal.”
“Among the other zoonoses of concern are plague, which has been spread from rodents to cats to humans; toxoplasmosis, which has been spread by free-roaming cats soiling water sources; and Lyme disease, which has been spread by infected ticks brought into the home by free-roaming cats.”

How do free-roaming and feral cats impact humans and wild animals? (1998) Animal Sheltering, May-June 1998
“When T. gondii infects…pregnant women it may cause a congenital syndrome that includes deafness, seizures, retinal damage, and mental retardation in the fetus or neonate. In immunocompromised individuals…it may produce severe central nervous system damage…Additional concerns have been raised by recent studies of schizophrenia, depression, suicidal behavior, obsessivecompulsive disorder, rheumatoid arthritis, brain cancer, and scholastic underachievement in children, which have reported correlations between such conditions and elevated T. gondii…”
“…10% of all deaths of people with HIV are directly from Toxoplasmosis.”
“T. gondii alone is sufficient reason to stop conducting TNR…”
“…a recent study…confirms previous reports of higher suicide rates in those infected with T. gondii.”
“…ocular toxocariasis…is terribly debilitating…blindness is the most common result, with children bearing the high portion of cases.”
“…many of the cat associated zoonoses are severe and can even include life threatening conditions, such as bubonic plague…”

Hillsborough Animal Health Foundation (2012) Public Health Issues. Hahf.org/awake/public-health-issues/
“…stray cats serve as major reservoirs for the bacterium Bartonella spp. And B. clarridgaiae. Consequently, stray cats and their fleas are the only known vectors for infecting house bound cats and humans with this bacterium. Human infections that may result from exposure of this bacterium via stray cats include: cat scratch disease…bacillary angiomatosis, hepatic peliosis…endocarditis, bacteremia, osteolytic lesions, pulmonary nodules, neuroretinitis, and neurological diseases.”

United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, United States Department of the Interior (2003) Management of feral and free-ranging cat populations to reduce threats to human health and safety and impacts to native wildlife species in the commonwealth of Puerto Rico. Environmental Assessment, 1-65
“…the Centers for Disease Control and Prevention has determined that feral cat colonies pose a threat to human health.”
“Up to 74 percent of all cats will host the toxoplasmosis-causing parasite in their lifetime and shed hundreds of millions of infectious eggs as a result. Any contact, either directly or indirectly, with cat feces risks human and wildlife health.”
“Multiple peer-reviewed studies, including the CDC’s, have found that TNR programs do not adequately reduce feral cat populations or effectively mitigate health concerns.”
“The only sure way to simultaneously protect wildlife and people is to remove feral cats from the landscape.”

American Bird Conservancy + 199 other agencies/organizations (2014) Letter to the Honorable Sally Jewell, Secretary, U.S. Dept. of the Interior. www.abcbirds.org
FERAL CATS PREDATE ON OTHER ANIMALS
“…cats are responsible for the extinction of at least 33 species of birds around the world.”
“Estimates from Wisconsin indicate that between 500,000 and 8 million birds are killed are killed by rural cats each year in that state (urban cats are not included in these estimates).”
“Predation by cats has an economic impact of more than $17 billion dollars per year in the U.S.”

Hildreth, A. M., Vantassel, S. M., Hygnstrom, S. E., (2010) Feral cats and their management. University of Nebraska, Extension, EC1781
“We estimate that free-ranging domestic cats kill 1.4-3.7 billion birds and 6.9-20.7 billion mamals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality. Our findings suggest that free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for US birds and mammals.” “Domestic cats…have been listed among the 100 worst non-native invasive species in the world. “We estimate that between 258 and 822 million reptiles and between 95 and 299 million amphibians could be killed by cats in the contiguous United States each year.”

Loss, S. R., Will, T., Marra, P. P., (2013) The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications DOI: 10.1038/ncomms2380
“…scientists now list invasive species, including cats, as the second most serious threat to declining and rare wildlife.” “The Mammal Society of England found that a minimum of 44 species of wild birds comprised 24% of the prey that cats brought home to their owners.” “Studies of prey items that pet cats bring home reveal only the bare minimum of what those cats actually kill. Animals killed by cats but consumed or left elsewhere, animals that escaped the cat but died later because of trauma or secondary infection, or young animals that starved to death or died of exposure because cats killed one or both parents are not counted in such studies.” “Scientific studies have also documented that declawing cats, putting bells on their collars, or keeping them well fed do not prevent them from killing animals…hunger and hunting behavior are controlled by different portions of a cat’s brain.” “…well-fed cats were observed stalking and killing birds…”

Winter, L., (2004) Trap-neuter-release programs: the reality and the impacts. JAVMA 225, 1369-1376.
“Even when cats do not directly kill birds, their mere presence has been shown to result in a reduction in the feeding of nesting chicks by one-third and an increased likelihood of nest failure by an order of magnitude.”

Sizemore, G., (2015) Do a little, save a lot: keep cats indoors. Louisiana Ornithological Society Newsletter, Winter 2015, 7.
“Feral cats are almost exclusively carnivorous and generally obtain most of their food resources by hunting live prey.” “Predation by feral cats can jeopardize conservation programs…and have non-lethal impacts on susceptible populations through competition, disease transmission, induced predator-avoidance behavior and hybridization.”

Doherty, T. S., Bengsen, A. J., Davis, R. A., (2015) A critical review of habitat use by feral cats and key directions for future research and management. Wildlife Research 10.1071/WR14159
“…cats…hunt even when fed daily by humans. Laboratory studies of cats suggest that hunger and hunting are controlled by separate neurological centers in the brain.”

Wallace, G., Ellis, J., (2003) Impacts of feral and free-ranging domestic cats on wildlife in Florida. Issue Assessment- Florida Fish and Wildlife Conservation Commission.
“…TNVR can cost over $100 per cat (including trapping, spaying/neutering, vaccination, and transport), and the cats are still able to prey on native birds and mammals.”

Opar, A., (2010) Feral cat predation on birds costs billions of dollars a year. Audubon, December 3, 2010
FERAL CATS HAVE A NEGATIVE IMPACT ON BIODIVERSITY
“Invasive mammalian predators are arguably the most damaging group of alien animal species for global biodiversity. Species such as cats…threaten biodiversity through predation, competition, disease transmission, and facilitation with other invasive species.” “The decline and extinction of native species due to invasive predators can have impacts that cascade throughout entire ecosystems. For example, predation by feral cats and red foxes has led to the decline or extinction of two thirds of Australia’s digging mammal species…”
“Rodents are linked to the extinction of 75 species…and cats to 63 extinctions…”
“Introduced rodents and cats are major agents of extinction, collectively being listed as causal factors in 44% of modern bird, mammal, and reptile species extinctions.”

Doherty, T. S., Glen, A. S., Nimmo, D. G., Ritchie, E. G., Dickman, C. R., (2016) Invasive predators and global biodiversity loss. Proceedings of the National Academy of Sciences 113 (40), 11261-11265
“…the rate of species extinctions is accelerating, with grave impacts on people around the world…”
“The health of ecosystems on which we and all other species depend is deteriorating mare rapidly than ever. We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide.”
“The number of invasive alien species per country have risen by about 70% since 1970”

Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (2019) The global assessment of biodiversity and ecosystem services. 7th session, IPBES Plenary
“The list of ‘100 of the World’s Worst Invasive Alien Species’ that is presented here is designed to enhance awareness of…the terrible consequences, of invasive alien species.”
“100 of the World’s Worst Invasive Alien Species…domestic cat (Felis catus)”

Lowe, S., Browne M., Boudjelas, S., De Poorter, M., (2000) 100 of the World’s Worst Invasive Alien Species. Special lift-out in Aliens 12, December 2000, 12pp.
“Attempting to maintain cats in colonies only compounds the problem by causing massive killing and crippling of native wildlife, jeopardizing biodiversity, undermining traditional animal control, enabling irresponsible people to abandoned cats, and sending mixed messages about the…commitment to serve the welfare of all species, including cats and wildlife.”

Jessup, D. A., (2004) The welfare of feral cats and wildlife. JAVMA 225 (9), 1377-1383
FERAL CATS HAVE A VERY POOR QUALITY OF LIFE “People for the Ethical Treatment of Animals (PETA) has called TNR “subsidized abandonment” and states that “feral cats do not die of ‘old age.’ They are poisoned, shot, tortured by cruel people, attacked by other animals, or hit by cars, or they die of exposure, starvation, or…contagious diseases…. In one feral cat colony, half of 32 cats were shot by a man who claimed that they were attacking his children. Cats in another colony were shot with darts. A loose dog killed several cats in another colony. Ferals often scratch their ears bloody, driven crazy by pain and itching of ear mites and accompanying infections. Others die of blood loss or anemia from worms and fleas. Urinary tract infections, which frequently lead to blockage in male cats, cause extremely painful, lingering death if not treated. Untreated upper respiratory infections leave eyes and noses so caked with mucus that animals can barely see or breathe.”
Many feral cats live short, brutal lives. Figures vary, but the AVMA has used the figure of 2 years as opposed to 10 for the mean lifespan of owned cats; others estimate that feral cats live approximately half as long as owned cats. Mortality rates for feral cats can be up to 80%/y. Feral cats suffer considerably higher rates of injury and disease. Many feral cats succumb to vehicle trauma, predation, disease, or severe weather. Winter has presented a number of examples of the dangerous and unsanitary conditions found at feral cat feeding sites. Clearly these conditions and outcomes are not serving the welfare of feral cats.”

Jessup, D. A., (2004) The welfare of feral cats and wildlife. JAVMA 225 (9), 1377-1383
“The average life expectancy of an “outdoor cat” is about two to five years compared with 12 to 15 years for a cat who lives indoors. Feral cats, as well as homeless domesticated cats who have been set loose outdoors by shelters seeking to avoid the criticism that they might face from euthanizing them, commonly suffer and die from feline leukemia, feline AIDS, and other infectious diseases—even rabies. They also succumb to ailments like anemia and upper respiratory infections—conditions that are easily treatable were the cats to be taken to a veterinarian—but they are not. In winter, cats in cold climates endure subzero temperatures, some losing ears, tails, or limbs to frostbite; others being cut to shreds when they climb into car engines seeking warmth; and still others simply freezing to death. Many cats “disappear”—and while some are hit by cars or attacked by dogs or wild predators and some succumb to parasites or starvation…others are victims of foul play.”

Nachminovitch, D., (2017) TNR is dangerous both to cats and to other animals. Voices for Wildlife, March 8, 2017
“Parasitism is the most common transmissable problem of feral cats…92% were infested with fleas and 37% had ear mites.”
“A study of 80 feral cats…revealed that 54% carried intestinal ascarids, compared with only 4% of 70 pet cats. Tapeworms and coccidia were found in 26% and 13% of feral cats, compared to 4% and 0% of pet cats, respectively. More feral cats (20%) were seropositive for Toxoplasma gondii than pet cats (3%)…In another study, Bartonella henselae was the most common infection identified in 553 (34%) feral cats…”
“…a kitten mortality rate of >50%...”

Levy, J. K., Crawford, P. C., (2004). Humane strategies for controlling feral cat populations. JAVMA 225, 1354-1360.
“The welfare of free-roaming cats concerns society because they are frequent victims of vehicular collisions and fights between themselves and other animals.”
“Published figures for survival rates of adults include 33% over a 42 month period…Anecdotal reports estimate adult life span of feral cats at 2 to 3 years.”

Andersen, M. C., Martin, B. J., Roemer, G. W., (2004) Use of matrix population models to estimate the efficacy of euthanasia versus trap-neuter-return for management of free-roaming cats. JAVMA 225, 1871-1876
“There are ethical concerns about the well-being of free-roaming cats, as individual health and survival may be severely challenged in urban populations…”
“…Nutter et al. 2004 examined free-roaming cat populations…as part of a Trap-Neuter-Return study, and found kitten mortality…as high as 75%.”

Kilgour, R. J., Magle, S. B., Slater, M., Christian, A., Weiss, E., DiTullio, M., (2017) Estimating free-roaming cat populations and the effects of a one year Trap-Neuter-Return management effort in a highly urban area. Urban Ecosyst 20, 207-216
“Overall, 127 of 169 (75%) kittens died or disappeared before 6 months of age. Trauma was the most common cause of death.”

Nutter, F. B., Levine, J. F., Stoskopf, M. K., (2004) Reproductive capacity of free-roaming domestic cats and kitten survival rate. JAVMA 225(9), 1399-1402

SUMMARY OF SCIENTIFIC LITERATURE

Title: Trap/Neuter/Release methods ineffective in controlling domestic cat “colonies” on public lands
Authors: D. Castillo, A. L. Clarke
Affiliations: Florida International University
Journal: Natural Areas Journal
Year: 2003

Summary
A study was conducted to identify the outcome of a managed trap-neuter-release (TNR) program in two county parks in Miami, Florida. TNR failed to reduce the population of cats at either park and the population at one park actually increased. Stray cats were attracted by food provided to the colony by caretakers, and the community pet owners used the colony as a dumping ground for abandoning pets.

Key Quotes
“The establishment of cat colonies in public parks and natural areas creates a number of wildlife conservation problems. The most serious of these problems are wildlife predation and disease transmission. Despite the fact that cat colony supporters assert that wellfed colony cats will not prey on wildlife, numerous scientific studies provide evidence to the contrary (e.g., Adamec1976; Biben 1979; Leyhausen 1979; Liberg 1984; Fitzgerald 1988; Fitzgerald and Turner 2000).” (p. 248) “Several outbreaks of toxoplasmosis in humans have been attributed to soil and water contaminated with oocysts shed from the feces of free-roaming cats (Patronek 1998).” (p. 248) “In 1994, five Florida children were hospitalized with encephalitis that was associated with cat-scratch fever (Patronek 1998).” (p. 248) “Our results contradict the assertion that managed cat colonies decline in size over time.” (p. 251) “The high number of cats and kittens that were dumped at the colonies throughout the course of our study confirms that the establishment of cat colonies on public lands with unrestricted access encourages illegal dumping of cats and creates…[a] nuisance.” (p. 252) “Our results suggest that trap, neuter, and release programs are not an effective method to help control the population of unwanted feral and free-roaming cats on public lands.” (p. 252) “We suggest that supporters of managed cat colonies seek a long-term solution to the pet overpopulation issue by redirecting their efforts toward the underlying problem of managing irresponsible pet owners.” (p. 252)

Title: Professional, ethical, and legal dilemmas of trap-neuter-return
Authors: P. L. Barrows
Affiliations: Active Environments Inc.
Journal: Journal of the American Veterinary Medical Association
Year: 2004

Summary
The author provides a veterinary medical practitioner’s perspective to the issue of how to deal with the problem of free-roaming cats. Specifically discussed are the professional, ethical, and legal dilemmas and disease concerns for people.

Key Quotes
“Cats are variably and correctly identified as nonnative, exotic, introduced, alien, foreign, or invasive species. Invasive species are defined as “species (animals, plants, microbes, etc.) alien or nonnative to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm, or harm to human health.” (p. 1) “Although well meaning, many advocates of TNR lack professional training in the biological, ecologic, and wildlife sciences. Consequently, they may misunderstand, minimize, or choose to ignore the documented concerns regarding the ecologic, domestic animal and public health, legal, humane, and social nuisance impacts of feral cats, including those in TNR programs.” (p. 1) The American Veterinary Medical Association’s Council on Environmental Issues (CEI) “has concluded [that] managed cat colonies do not solve the problems of cat overpopulation and suffering, wildlife predation, or zoonotic disease transmission.” (p. 1366) The CEI “strongly supports and encourages humane elimination of feral cat colonies.” (p. 1366) The CEI “opposes passage of local or state ordinances that legalize the maintenance of managed (i.e., TNR) cat colonies.” (p. 1366) “Despite cats being the most frequently reported rabid domestic animal in the United States, proponents of TNR rarely address the fatal nature of untreated human rabies infections, nor do they readily acknowledge that nearly all TNR colonies contain unvaccinated cats or previously immunized cats whose immunity against rabies is diminished or has disappeared.” (p. 1367) “The CEI has expressed its concern regarding potential legal liability for veterinarians and other allied professionals who opt to participate in TNR programs.” (p. 1368) “Free-roaming dog colonies have not been condoned and neither should free-roaming cat colonies. Arguing that cats warrant preferential treatment ignores the damage they cause and the risks they pose.” (p. 1368)

Title: The welfare of feral cats and wildlife
Author: D. A. Jessup
Affiliations: Marine Wildlife and Veterinary Care and Research Center
Journal: Journal of the American Veterinary Medical Association
Year: 2004

Summary
The author discusses the impacts of Trap-Neuter-Release (TNR) programs on the welfare of cats and wildlife, identifies why TNR is inappropriate, and suggests alternative actions to address the feral cat population.

Key Quotes
“Attempting to maintain cats in colonies only compounds the problem by causing massive killing and crippling of native wildlife, jeopardizing biodiversity, undermining traditional animal control, enabling irresponsible people to abandon cats, and sending mixed messages about the veterinary profession’s commitment to serve the welfare of all species, including cats and wildlife.” (p. 1377) “Providing abundant food for outdoor cats, even overfeeding, does not stop this…hunting behavior.” (p. 1377) “The loss of [wildlife caused by cats] reduces biodiversity, even in somewhat degraded ecosystems. Loss of their ecosystem services has implications for such basic life processes as insect population dynamics, soil fertility and stability, pollination, and seed dispersal.” (p. 1378) “Wild animals are not only killed by cats but are also maimed, dismembered, ripped apart, and gutted while still alive, and if they survive the encounter, they often die of sepsis because of the virulent nature of the oral flora of cats.” (p. 1378) “In the world of TNR, unless a stray cat has a collar or is microchipped, it is very difficult to distinguish from a truly feral animal. Once trapped, neutered, and marked, these lost cats are much less likely to ever be found and returned to their owners or adopted. Trap, neuter, and reabandonment is a cruel fate for many former pet cats.” (P. 1378) “Figures vary, but the AVMA has used the figure of 2 years as opposed to 10 for the mean lifespan of owned cats; others estimate that feral cats live approximately half as long as owned cats. Mortality rates for feral cats can be up to 80%/yr. Feral cats suffer considerably higher rates of injury and disease. Many feral cats succumb to vehicle trauma, predation, disease, or severe weather.” (p. 1379) “Maintaining feral cats where they can deposit cat feces in national, state, county, or city public parks; on campuses; and around schools and hospitals constitutes a public health risk.” (p. 1379) “Trap-neuter-return’s failures are, in part, attributable to its being based on several false assumptions, including the following: rates of abandonment and immigration are relatively low; cats at existing sites will exclude others (in reality the presence of food attracts others); feral cats will stay where you put them (you cannot herd cats, well fed or not); all cats can be caught; and populations of cats in colonies will behave in general as if they were isolated and in a closed system.” (p. 1380)

Title: Critical assessment of claims regarding management of feral cats by trap-neuter-return
Authors: T. Longcore, C. Rich, and L. M. Sullivan
Affiliations: The Urban Wildlands Group, University of Southern California Los Angeles
Journal: Conservation Biology
Year: 2009

Summary
The authors compared claims made by feral cat advocates to the scientific literature. Advocate claims were found to be contradictory to the literature, and the authors suggest a role for conservation biologists in conducting research and disseminating the results of that research to educate the general public and policy makers.

Key Quotes
“Domestic cats are on the list of the 100 worst invasive species globally (Lowe et al. 2000).” (p. 888) “The stated goals of [no kill programs] is for feral cats to be recognized as ‘protected healthy wildlife [that] should not enter shelters in the first place.’” (p. 888) “Unfortunately, TNR does not eliminate feral cat colonies under prevailing conditions (Jessup 2004; Winter 2004, 2006) and many false claims used to support the approach go unchallenged.” (p. 888) “[TNR] advocates argue that studies showing adverse effects of feral cats on islands do not apply to continents (Gorman and Levy 2004; Alley Cat Allies 2005). In urban and suburban areas, natural habitats resemble islands, where fragments are surrounded by an inhospitable matrix, but unlike on islands, the inhospitable areas serve as an ongoing source of subsidized predators (Walter 2004).” (p. 888) “Feral cats are exotic and do not fill an existing niche.” (p. 889) “Feral cats are generally found at densities 10-100 times higher than similarly sized native predators (Nowell and Jackson 1996; Liberg et al. 2000).” (p. 889) “Feeding by humans reduces the average range size of free-roaming cats, but increases densities, concentrating predation on wildlife where feeding occurs (Schmidt et al. 2007).” (p. 889) “Contrary to claims that well-fed cats pose little threat to wildlife, hunting and hunger are not linked in domestic cats (Adamec 1976). Even well-fed cats hunt and kill lizards, small mammals, birds, and insects (Liberg 1984; Castillo and Clarke 2003; Hutchings 2003).” (p. 889) “We argue that it is philosophically inappropriate for population-level impacts to be the only criteria by which the effects of cats are judged…We see no justification for valuing birds and other wildlife only as populations while valuing cats as individuals.” (p. 890) 11 “Over 80% of the prophylactic treatments administered to humans in the United States for possible exposure to rabies resulted from contact with stray or feral cats (Moore et al. 2000).” (p. 890) “Studies show elevated infection rates of disease-causing pathogens in stray and feral cats compared with owned cats as a whole, including those that roam (Dubey 1973; Nutter et al. 1974; Norris et al. 2007).” (p. 890) “Fecal matter from feral and free-roaming cats degrades water quality (Dabritz et al. 2006).” (p. 890) “The definition of a successful TNR program for feral cat advocates is almost always different from what a conservation biologist or policy maker might view as a successful feral cat management program. For many TNR advocates, success is not defined by elimination of feral cats in an area, but rather by the welfare of the cats.” (p. 891) “Feral cat advocates usually argue that managed colonies are stable and resist invasion by cats from surrounding areas (Berkeley 2004), but this assertion is not consistent with scientific literature or reports from TNR colonies (Stull 2007).” (p. 891)

Title: Zoonotic diseases associated with free-roaming cats
Authors: R. W. Gerhold, D. A. Jessup
Affiliations: The University of Tennessee, California Department of Fish and Game
Journal: Zoonoses and Public Health
Year: 2012

Summary
The authors review the various diseases of free-roaming cats and the public health implications associated with free-roaming cat populations.

Key Quotes
“Free-roaming cats often lack the necessary preventative care to control [infectious diseases] and consequently pose a potential health threat to other domestic animals, wildlife, and humans.” (p. 1) “Since 1988, rabies has been detected more frequently in cats than dogs in the United States (Rupprecht 2002), and in 2008 the number of rabies cases in cats (n = 294) was approximately four times the number of cases in dogs (Blanton et al. 2009). In 2010, rabies cases declined in all domestic animals, except for cats, which comprised 62% (n = 303) of all rabies cases in domestic animals (Blanton et al. 2011).” (p. 2) “Multiple studies have disclosed that human exposure to rabies is largely associated with free-roaming cats because of people being more likely to come in contact with cats, large free-roaming cat populations, and lack of stringent rabies vaccination programs (Childs 1990; Cole and Atkins 2007; Roseveare et al. 2009; Eidson and Bigman 2010).” (p. 2) “Individuals exposed to potentially rabid animals are administered PEP, and cat exposures account for approximately 1/3 of all PEP recipients. Post-exposure prophylaxis regimen generally costs $5000-$8000 for each individual, which is mostly borne by public health agencies (Recuanco et al. 2007).” (p. 2) “TNR advocates are unlikely to administer rabies immunization of all free-roaming cats. This is significant because one rabid cat in an aggressive (i.e., furious rabies) condition can lead to multiple exposure events because furious rabid animals often seek potential hosts to bite…rabid cats were significantly more likely than rabid dogs to bite a person (62% vs. 36%) (Eng and Fishbein 1990).” (p. 2) “The risk of being seropositive for [feline leukemia virus or feline immunodeficiency virus] was most frequently associated with being free-roaming, followed by having access to outdoors.” (p. 3) “The 2011 Compendium of Animal Rabies Prevention and Control states that stray animals including cats should be removed from the community through local health departments and animal control officials (Brown et al. 2011).” (p. 3) “Data suggest that neutered cat groups act as attractant of sexually intact free-roaming cats, thus negating the belief that TNR program leads to [a] decrease in free-roaming cat populations.” (p. 3) “Free-roaming cat colony feeding stations attract wild mesocarnivores (Gehrt 2003), potentially exacerbating human rabies exposure incidents.” (p. 3) “Domestic and wild felids are the definitive host for…Toxoplasma gondii and the ascarid Toxocara cati…The host-defecated eggs (Toxocara) or oocysts (Toxoplasma) of these parasites are extremely environmentally resistant (Long 1990; Kazacos 2001), and human infections can occur months or possibly even years after the cat has excreted the parasite egg. For this reason, cat fecescontaminated playgrounds, garden soil, sandboxes, and other outdoor recreational areas may serve as a source of infection for humans (Holland and Smith 2006; Lee et al. 2010).” (p. 3-4) “Toxoplasma infections can manifest as ocular diseases, neurological impairment, and lead to blindness, abortions, and birth defects, particularly hydrocephalus, in humans (Dubey and Odening 2001). Toxoplasmosis is also a significant risk for individuals receiving immunosuppressive therapy, transplant recipients, and is a major cause of systemic infection and death for immunosuppressed (e.g., HIV/AIDS) patients (Elmore et al. 2010). An increased risk of schizophrenia, autism, Alzheimer’s, and other neuro-inflammatory diseases has been proposed with T. gondii infection (Fekadu et al. 2010; Prandota 2010).” (p. 4) “Approximately 75% of free-roaming cats in Florida were positive for [one species of hookworms], and 33% were positive for [another hookworm species] (Andersen et al. 2003).” (p. 4) “Three major flea-associated diseases of cats in the United States include cat-scratch disease (CSD), flea-borne typhus, and plague (McElroy et al. 2010).” (p. 4) “Human bacterial diseases, including tularemia…and plague…have been associated with direct contact with cats or cat fleas (Liles and Burger 1993; Gage et al. 2000; McElroy et al. 2010). Approximately, 8% of plague cases in the United States are associated with transmission from cats, and cases of cat exposure associated plague are reported year round where flea-associated cases are generally restricted to warmer months (Gage et al. 2000).” (p. 5) “Rabies exposure in humans is disproportionately associated with free-roaming cats compared to other domestic animals. This fact should be of paramount concern to public health officials because of the high mortality rate of clinical rabies and the significant cost of PEP in exposed people.” (p. 5)

Title: The impact of free-ranging domestic cats on wildlife of the United States
Authors: Scott R. Loss, Tom Will, Peter P. Marra
Affiliations: Smithsonian Conservation Biology Institute, U.S. Fish and Wildlife Service
Journal: Nature Communications
Year: 2013

Summary
Using a data-driven systematic review of previously published studies that estimated predation rates of owned and un-owned cats, the authors quantitatively estimated total mortality caused by cats in the contiguous United States. The results showed that free-roaming domestic cats kill 1.4-3.7 billion birds and 6.9-20.7 billion mammals every year. The majority of this mortality is caused by un-owned cats, whose predation rates averaged three times greater than rates for owned cats.

Key Quotes
“Cat predation on wildlife…may exceed all other sources of anthropogenic mortality of U.S. birds and mammals.” (p. 2) “We excluded high local predation rates and used assumptions that led to minimum predation rates for un-owned cats; therefore, actual numbers of birds killed may be even greater than our estimates.” (p. 4) “Native species make up the majority of the birds preyed upon by cats.” (p. 4) “For all North American land birds, the group of species most susceptible to mainland cat predation, existing estimates range from 10-20 billion individuals in North America.” (p. 5) “Threatened species in close proximity to cat colonies – including managed TNR colonies – face an especially high level of risk; therefore, cat colonies in such locations comprise a wildlife management priority.” (P. 5) “Claims that TNR colonies are effective in reducing cat populations, and, therefore, wildlife mortality, are not supported by peerreviewed scientific studies.” (p. 5)

Title: Feral cats: Do Trap=neuter-Return programs work?
Authors: Tom Gotsis
Affiliations: New South Wales Parliamentary Research Service
Journal: NSW Parliamentary Research Service, e-brief issue 18/2014
Year: 2014

Summary
Utilizing 100 previously published studies the author summarizes their findings and concludes that TNR programs are ineffective at reducing feral cat populations and that they pose a significant threat to native wildlife.

Key Quotes
“For medium or large populations of feral cats the BBN calculated that the optimal population control measure was euthanasia. As Loyd and DeVore explain, other studies support their results: Trap-euthanize strategies have proven effective at reducing cat populations and mitigating adverse effects on wildlife in a number of locations. In contrast, TNR programs alone have never been shown to stabilize a feral cat population in the scientific literature.” “Andersen, Martin and Roemer’s matrix population model predicted cat populations to have high intrinsic growth rates. It further predicted that euthanasia was likely to be more effective at controlling cat populations than TNR: Reducing cat survival (by increasing euthanasia rates) would likely have a greater effect on cat population growth than reducing fecundity (by increasing sterilisation rates).” “Castillo and Clarke studied two TNR programs in Florida… Neither study reduced cat numbers.”

Title: Evaluation of euthanasia and trap-neuter-return (TNR) programs in managing free-roaming cat populations
Authors: Paige M. Schmidt, Todd M. Swannack, Roel R. Lopez, Margaret R. Slater
Affiliations: College of Veterinary Medicine, Texas A&M University, Department of Wildlife and Fisheries Sciences
Journal: Wildlife Research
Year: 2009

Summary
The authors evaluated free-roaming cat control methods using a demographic population model for a 25 year period to determine the effectiveness of both TNR and euthanasia.

Key Quotes
“Our results are consistent with long-term evaluations of TNR colonies that showed population abundance failed to decrease because of immigration (Castillo and Clark 2003) and with studies that showed high rates of transients and population turnover in feral cats (Langham and Porter 1991; Genovesi et al. 1995).” “Our model results also are consistent with initial evaluations of TNR campaigns (Castillo and Clark 2003; Foley et al. 2005; Natoli et al. 2006). TNR was not effective at reducing free-roaming cat numbers…”

Title: Analysis of the impact of trap-neuter-return programs on populations of feral cats
Authors: Patrick Foley, Julie K. Levy, Terry Paik
Affiliations: Department of Biological Sciences, University of California, College of Veterinary Medicine, University of Florida
Journal: Journal of American Veterinary Medical Association
Year: 2005

Summary
Using a theoretical population model, the authors evaluate two county TNR programs to assess the impact they have on feral cat populations.

Key Quotes
“Our analysis indicated that any population-level effects were minimal.” “Implementation of the stage-structured model suggested that no plausible combinations of life history variables would likely allow for TNR to succeed in reducing population size, although neutering approximately 75% of the cats could achieve control (which is unrealistic), a value quite similar to results in the present study.” “Feral cat control programs are notoriously difficult, and in many cases, short-term control has been followed by a long-term return to precontrol conditions.”

Title: Evaluation of the effect of a long term trap-neuter-return and adoption program on a free-roaming cat population
Authors: Julie K. Levy, David W. Gale, Leslie A. Gale
Affiliations: College of Veterinary Medicine, University of Florida
Journal: Journal of American Veterinary Medical Association
Year: 2003

Summary
The authors evaluated the effect of a long-term trap-neuter-return program, with adoption whenever possible, on the dynamics of a free-roaming cat population.

Key Quotes
“More than 1,000 veterinary members of the California Veterinary Medical Association neutered more than 170,000 cats between July 1999 and May 2002 in a $12 million project funded by Maddie’s Fund. However, virtually no information exists to support the contention that neutering is an effective long-term method for controlling free-roaming cat populations.” “A 1-year studyb of TNR programs in 2 southern Florida parks revealed that the presence of well-fed cat colonies encouraged illegal abandonment of additional cats. While the original population of 81 cats declined 20% during 1 year, the arrival of new cats prevented reduction of the colonies, and 88 cats were present at the end of the study. Results of the study also refuted an oft-cited claim that an established colony of cats will defend its territory and prevent the immigration of new arrivals.” “It is proposed that a mortality rate of > 50% in free-roaming kittens prior to maturity contributes to the relatively stable population of cats.” “Immigration or abandonment of new cats may be a frequent event, and free-roaming cats do not appear to have sufficient territorial activity to prevent new arrivals from permanently joining colonies. These new arrivals could substantially limit the success of TNR…”