Trap-neuter-return Research Articles

Imposing ferality: a technopolitical analysis of feral and free-roaming animal classification technologies

ABSTRACT Ferality, as a concept, may be a hopeful potential of thriving life in the Anthropocene; however, ferality remains problematically grounded in contested nature-culture binaries. Government programs continue to use ferality as a classification and valuation technology, and ultimately, as a mathematical solution to a political nightmare. By approaching trap-neuter-return (TNR) policies in Miami through a technopolitical framework, this paper critically examines technologies used to identify, measure, and value free-roaming urban animals through programs to make them either live or die for strategic political agendas. TNR programs homogenize entire populations of “feral” animals. Miami’s TNR of kittens demonstrates the need for policies that acknowledge heterogeneous free-roaming animal experiences. This case study unpacks the fleshly consequences of reducing complex nonhuman animal histories to abstract statistical performance metrics. Detailed analysis of this management technology illustrates links between public pressure, political interest, and the perceived need to manage human-nonhuman relations in dense urban spaces.

Classification of the Trap-Neuter-Return Surgery Images of Stray Animals Using Yolo-Based Deep Learning Integrated with a Majority Voting System

Trap-neuter-return (TNR) has become an effective solution to reduce the prevalence of stray animals. Due to the non-culling policy for stray cats and dogs since 2017, there is a great demand for the sterilization of cats and dogs in Taiwan. In 2020, Heart of Taiwan Animal Care (HOTAC) had more than 32,000 cases of neutered cats and dogs. HOTAC needs to take pictures to record the ears and excised organs of each neutered cat or dog from different veterinary hospitals. The correctness of the archived medical photos and the different shooting and imaging angles from different veterinary hospitals must be carefully reviewed by human professionals. To reduce the cost of manual review, Yolo’s ensemble learning based on deep learning and a majority voting system can effectively identify TNR surgical images, save 80% of the labor force, and its average accuracy (mAP) exceeds 90%. The best feature extraction based on the Yolo model is Yolov4, whose mAP reaches 91.99%, and the result is integrated into the voting classification. Experimental results show that compared with the previous manual work, it can decrease the workload by more than 80%.

Trap-Neuter-Return: A Study of the Practice in Switzerland

Trap-Neuter-Return (TNR) is well-established in many countries and increasingly considered to be the most effective and humane way to manage feral and stray cat populations. Nonetheless, it confronts major challenges everywhere it is practiced. Although Switzerland has an impressive TNR system carried out mainly by private, non-profit organizations and individual citizens, the management of feline overpopulation could be strengthened by improvements on a number of fronts, including legal and governance changes, education and modifications in mentality, and operational adjustments such as data management and analysis. TNR faces a number of common challenges worldwide, and given that it is still relatively young, lessons from one country can be valuable for another. Because little has been written about TNR in Switzerland, this article seeks to fill this gap by providing a preliminary analysis of the case through the prism of existing analytical work done on TNR in other countries.

Cats Are Not Fish: A Ricker Model Fails to Account for Key Aspects of Trap-Neuter-Return Programs.

Simple SummaryVarious population models have been used to predict the sterilization effort necessary to reduce free-roaming cat numbers through trap–neuter–return (TNR) programs. Among these is a Ricker model, first developed for application in the management of fisheries. We tested this model by using data from two long-term (i.e., >20 years) TNR programs with well-documented population reductions. Doing so revealed that the model cannot account for some key aspects of typical TNR programs. This model is therefore inappropriate for use in assessing the effectiveness of TNR programs. A more recently developed model that accounts for the movement of cats in and out of a given area is better suited for modeling TNR programs.In a frequently cited 2005 paper, a Ricker model was used to assess the effectiveness of trap–neuter–return (TNR) programs for managing free-roaming domestic cat populations. The model (which was originally developed for application in the management of fisheries) used data obtained from two countywide programs, and the results indicated that any population reductions, if they existed, were at best modest. In the present study, we applied the same analysis methods to data from two long-term (i.e., >20 years) TNR programs for which significant population reductions have been documented. Our results revealed that the model cannot account for some key aspects of typical TNR programs, and the wild population swings it predicts do not correspond to the relative stability of free-roaming cat populations. A Ricker model is therefore inappropriate for use in assessing the effectiveness of TNR programs. A more recently developed, stochastic model, which accounts for the movement of cats in and out of a given area, is better suited for predicting the sterilization effort necessary to reduce free-roaming cat numbers through TNR programs.

Coping With Human-Cat Interactions Beyond the Limits of Domesticity: Moral Pluralism in the Management of Cats and Wildlife.

Although human interactions with cats are often even typically analyzed in the context of domesticity, with a focus on what sorts of interactions might make both people and cats “happy at home,” a large number of cats in the world live, for one reason or another, beyond the bounds of domesticity. Human interactions with these more or less free-living cats raise deeply controversial questions about how both the cats and the people they interact with should be sensibly managed, and about the moral imperatives that ought to guide the management of their interactions through the laws and public policies regulating both human interactions with pets and with wildlife. We review the geography of human interactions with cats living beyond the bounds of domesticity. We acknowledge the contributions made to ideas about how to manage cats by the animal protection movement. We review the tensions that have emerged over time between advocates for the eradication of free-living cats, because of the impacts they have on native wildlife species, and those who have imagined alternatives to eradication, most notably one or another variant of trap-neuter-return (TNR). The conflict over how best to deal with cats living beyond the bounds of domesticity and their wildlife impacts raises the prospect of stalemate, and we canvass and critique possibilities for moving beyond that stalemate.

Population Dynamics of Community Cats Living in a Tourist Area of Onomichi City, Japan, before and after the Trap-Test-Vaccinate-Alter-Return-Monitor Event

ABSTRACT The community cat program (CCP) was recommended by the Ministry of the Environment to reduce cats in local animal shelters and improve stray cat welfare in Japan. It is a non-lethal control measure with stray cats cared for as free-roaming cats for their lifetime in the community, while Trap-Neuter-Return (TNR) or Trap-Test-Vaccinate-Alter-Return-Monitor (TTVARM) activities are carried out. In the CCP, community cat colonies are hypothesized to be closed and static populations. However, it remains unknown whether the cats stay in the colonies, without migration of non-neutered cats following TNR/TTVARM events. We examined the population dynamics of cats before and after a TTVARM event using route censuses (107 days), fixed-point observations, and GPS-tracking in a tourist area in Onomichi. Eleven out of the 30 cats remained in the CCP areas, whereas 13 non-neutered cats immigrated into the CCP areas, within a year, suggesting the CCP program has limited efficacy. Besides, the program cannot support the lifetime management of the cats due rapid turnover of cats. Our results reject the CCP hypothesis, so that the program neither restricts cat breeding nor enhances cat welfare.

Investigational study on the population of feral cats in Pyeongtaek city, 2019

Feral cats are widely considered to be leading the potential impacts on public health. This study aimed to provide estimates of vital data for feral cats relating Trap-Neuter-Return (TNR) to establish strategies effectively to manage feral cats in Pyeongtaek. Thus, this study focused on estimating feral cat population in Pyeongtaek and conducted a comparative analysis of the data for feral cats in Seoul (2013). The number of feral cats was estimated from 23,069 to 26,655 in Pyeongtaek, 2019. In relation to human population, when comparing the number of feral cats of Pyeongtaek and Seoul, it ranged from 4.57% to 5.28%, and from 1.97% to 2.55% respectively. This showed that Pyeongtaek was higher than Seoul. Fewer kittens were found in high-density areas, which the TNR project is believed to be generally effective in controlling the number of feral cats. In conclusion, in urban and rural complexes such as Pyeongtaek City, the number of feral cats compared to the population was higher than that of Seoul City, and the TNR program is believed to be somewhat effective in controlling the number of feral cats. When implementing TNR, it is necessary periodically to investigate the population and reflect them in policymaking.

Serologic and urinary survey of exposure to Leptospira species in a feral cat population of Prince Edward Island, Canada.

ObjectivesRecent studies show that cats could play an important role in the transmission of Leptospira species. There are few reports of leptospirosis on Prince Edward Island (PEI) and none in cats. The objective of this study was to determine the prevalence of serum antibodies against Leptospira serovars and of Leptospira DNA in the urine of a population of free-roaming cats.MethodsPaired blood and urine samples were collected from 200 cats brought to a trap–neuter–return program. Antibody titers against six Leptospira serovars (Bratislava, Canicola, Gryppotyphosa, Hardjo, Pomona, Icterohaemorrhagiae) were determined by microscopic agglutination test. PCR was performed on urine samples to identify urine shedding of Leptospira DNA.ResultsAntibodies were detected in 20/200 cats (10%) for at least one serovar, with titers ranging from 1:50 to 1:6400 (all serovars tested, except Hardjo). Urine samples of 7/200 cats (3.5%) were PCR-positive.Conclusions and relevanceFeral cats in PEI had a higher than expected exposure to leptospirosis and can shed DNA from pathogenic Leptospira species in urine. Further studies are needed to determine the prevalence of exposure to leptospirosis in other species on PEI and the potential role of feral cats in transmission of the disease.

Free-ranging domestic cat abundance and sterilization percentage following five years of a trap–neuter–return program

Increasing free-ranging cat populations are a cause of concern for wildlife management and biodiversity conservation. Cats carry and transmit multiple diseases, annually depredate billions of birds and mammals in the mainland United States, and have caused extinctions and declines of wildlife populations worldwide. Trap–neuter–return (TNR) efforts, which entail trapping, sterilizing and releasing unowned free-ranging cats with the goal of reducing populations, have been implemented globally despite limited evidence of their ability to reduce cat numbers. To assess the effectiveness of a TNR program initiated in 2013 in Stillwater, Oklahoma, USA, we used trail cameras at 15 locations to estimate changes in cat abundance and the percentage of ear-tipped (i.e. sterilized) individuals between 2014 and 2018. We reviewed photographs to identify individual cats, and after accounting for detectability with mark–resight analyses, we estimated a non-significant decrease in abundance from 62 to 48 total cats across sampled locations. In 2018, approximately 27% of cats were ear-tipped compared to 0% in 2014, yet this percentage remains far below estimated sterilization levels needed for TNR to reduce unowned cat populations. Although additional long-term monitoring is needed, our results suggest that TNR conducted at its current intensity is unlikely to reduce Stillwater's cat population. Our research adds further evidence to the growing body of scientific literature indicating that TNR is ineffective in reducing cat populations.

Health Status of 'Community Cats' Living in the Tourist Area of the Old Town in Onomichi City, Japan

ABSTRACT The “community cat program (CCP)” is a non-lethal control measure in which stray cats are owned and cared for as community cats at high welfare standards, while the Trap-Neuter-Return (TNR) or Trap-Test-Vaccinate-Alter-Return-Monitor (TTVARM) event is performed. The program is recommended by the Ministry of the Environment in Japan. Here, we evaluated the health status of community cats inhabiting a tourist area in Onomichi City. A medical check was conducted on 30 community cats as a part of the TTVARM event. The following health problems were identified: alopecia, gingivitis, incisor teeth loss, anemia, and urine glucose. An ELISA (the enzyme linked immunosorbent assay) showed that 16.7% of the cats were FIV-positive. The cats were also carriers of zoonoses (Capnocytophaga genus (100%) and Bartonella henselae (ITS, nested; 38.0%)), which pose a risk to tourists and residents. Our findings suggest that most cats require medical treatment. We recommend that friendly cats should be adopted rather than maintained as community cats and that a comprehensive review of the CCP is required.

Estimates of wildlife killed by free-ranging cats in China

Throughout much of the world, growing populations of free-ranging domestic cats pose an increasingly serious threat to biodiversity. However, no study has estimated the magnitude of wildlife mortality caused by cats in China, one of the largest and most biodiverse nations on earth. We used a novel, survey questionnaire-based approach to estimate annual predation on wildlife by cats in China; we separately considered predation rates in urban and rural areas and by both owned free-ranging cats and unowned cats (e.g., feral and semi-feral cats including those associated with feeding and trap-neuter-return (TNR) activities). Using statistical simulations based on 2187 questionnaire responses that included direct observations of prey returns to owners and predation events by unowned cats, we estimate that the minimum annual amount of predation by all free-ranging cats in China is: 1.61-4.95 billion invertebrates, 1.61 -3.58 billion fishes, 1.13-3.82 billion amphibians, 1.48-4.31 billion reptiles, 2.69-5.52 billion birds, and 3.61-9.80 billion mammals. Thus, we show that free-ranging cats cause a tremendous death toll that may be profoundly impacting China’s wildlife populations and biodiversity. Our results indicate that there is an urgent need for increased research into the impacts of cats on wildlife in China, and for management and policy that reduces numbers of free-ranging cats and thus mitigates their harmful effects on China’s wildlife.

The Impact of Targeted Trap-Neuter-Return Efforts in the San Francisco Bay Area.

Simple SummarySubstantial and sustained reductions in community cat populations associated with trap–neuter–return (TNR) programs have been documented in a variety of locations, including in the northeastern, midwestern, and southeastern United States, as well as Australia. The present study adds to this growing body of evidence by examining the impact of a TNR program on a population of community cats living on a two-mile section of a pedestrian trail adjacent to the San Francisco Bay. An initial population of 175 cats declined by 99.4% over the 16-year program period. Of the 258 total cats enrolled between 2004 and 2020, only one remained at the end of the program period. The results of the present study corroborate previous research findings. Recently, a growing collection of evidence that associates trap–neuter–return (TNR) programs with substantial and sustained reductions in community cat populations across a variety of environments has emerged. Peer-reviewed studies emanating from the northeastern, midwestern, and southeastern United States, as well as Australia, document such reductions. The present study expands upon this body of evidence by examining the impact of a long-term TNR program on a population of community cats residing on a pedestrian trail adjacent to an oceanic bay located on the West Coast of the U.S. A population of 175 community cats, as determined by an initial census, living on a 2-mile section of the San Francisco Bay Trail declined by 99.4% over a 16-year period. After the conclusion of the initial count, the presence of cats was monitored as part of the TNR program’s daily feeding regimen. Of the 258 total cats enrolled in the program between 2004 and 2020, only one remained at the end of the program period. These results are consistent with those documented at the various sites of other long-term TNR programs.

Evidence for Citation Networks in Studies of Free-Roaming Cats: A Case Study Using Literature on Trap–Neuter–Return (TNR)

Simple SummaryAll aspects of an argument need to be evaluated in evidence-based scientific pursuit to prevent the development of self-reinforcing cohorts of studies through the cross-referencing of selected subsets of studies (citation bias). Controling populations of unowned cats using Trap–Neuter–Return and its variants (hereafter TNR) is an example of how a scientific topic develops and is communicated academically and publicly. We found 145 TNR publications between 2002–2019, with the last two years seeing a rapid increase in studies. Publication clusters occur, focusing on: population control, interactions with wildlife, disease transmission (including implications for pet cats, wildlife and humans), free-roaming cats, and feral and domestic cat management. A quarter of all studies were published in Open Access formats, which have the highest potential social impact because they are free to download, share and read. While it is encouraging that diverse views are expressed, the development of clusters of introspective topics risks reduced dialogue between groups of authors with differing views. Journal editors could encourage exchanges between groups by choosing reviewers from different camps to assess manuscripts and by asking authors to acknowledge alternative views.Trap–Neuter–Return and its variants (hereafter TNR) aims to control unowned cat populations. Papers on this topic form a useful case study of how how an area of literature grows, papers become influential, and citation networks form, influencing future study as well as public perceptions of the science. We analysed 145 TNR studies published 2002–2019. Common topics, identified by frequently used language, were population control, interactions with wildlife, disease transmission (including implications for pets, wildlife and humans), free-roaming cats, and feral and domestic cat management. One or more papers on each of these topics was judged influential because of high citations overall, high average citations/year, or frequent mentions in social media. Open Access papers were more influential in social media, raising greater public awareness than studies published in journals that were less accessible. While divergent views exist on a range of topics, the network analysis of the TNR literature indicated potential for forming self-reinforcing groups of authors. While it is encouraging that diverse views are expressed, there is a risk of reduced dialogue interactions between groups, potentially constraining dialogue to refine arguments, share information, or plan research. Journal editors could encourage communication by choosing reviewers from different camps to assess manuscripts and by asking authors to acknowledge alternative views.

Effects of the Community Cats Program on Population Control, Migration and Welfare Status of Free-Roaming Cats in Tokyo, Japan.

Simple SummaryThe community cats program (CCP), which includes trap–neuter–return activities, has been promoted in Japan to reduce the population of free-roaming cats without harmful effects on their welfare. To ascertain the effects of the CCP, a two-year survey of free-roaming cats was conducted in an area with CCP and another area without CCP in urban Tokyo, Japan. The estimated number of cats was lower in the CCP area than the non-CCP area, but there was no difference in the rate of decline in cat populations between areas. More cats disappeared (moved out, died, or entered homes) than appeared (moved in or born) in both areas in the second year and more males tended to move into the CCP area. There was no difference in the behavior of cats between areas and among seasons. The proportion of cats with poor health was lower in the CCP area than the non-CCP area. These results suggest that the CCP may improve the welfare of free-roaming cats. As the effect of CCP was restrictive in reducing free-roaming cats, the further promotion of neutering of cats may be necessary.The community cats program (CCP), which includes trap–neuter–return activities, has been promoted in Japan to reduce the population of free-roaming cats without harmful effects on their welfare. To ascertain the effects of the CCP, a two-year route census of free-roaming cats was conducted in an area with CCP and the other area without CCP in urban Tokyo, Japan. The estimated number of cats was lower in the CCP area than the non-CCP area, but there was no difference in the rate of decline in cat populations between areas. More cats emigrated or disappeared rather than immigrated in both areas in the second year and more males tended to immigrate into the CCP area. There was no difference in the behavior of cats between areas and among seasons. The proportion of cats with poor health was lower in the CCP area than the non-CCP area. These results suggest that the CCP may improve the welfare of free-roaming cats. As the effect of CCP was restrictive in reducing the population of free-roaming cats, the further promotion of neutering of cats may be necessary to reduce the population density of cats.

Application of a high-quality, high-volume trap-neuter-return model of community cats in Seoul, Korea.

BackgroundThis study was performed to determine the characteristics of community cats that were admitted to trap–neuter–return(TNR) programs and the feasibility of the high-quality, high-volume spay/neuter (HQHVSN) model in Seoul, Korea.MethodsTNR programs were performed eight times from 2017 to 2018, and a total of 375 community cats from the pilot areas were admitted. The pilot areas were selected regions wherein caregivers voluntarily participated in our TNR program. Each cat was anesthetized, assessed for health status, sterilized, vaccinated against feline viral rhinotracheitis, calicivirus and panleukopenia (FVR-CP), and rabies, and treated with insecticide after surgery. The time from anesthesia to recovery was evaluated to verify the efficiency of surgical time of the program. The TNR program at a local animal hospital and the program in this study were compared to assess the veterinary treatment administered and the cost for each cat.ResultsA total of 375 cats were underwent TNR in this study, including 192 (51.2%) intact females, 180 (48%) intact males, and three (0.8%) sterilized cats. Following surgery, 372 cats (99.2%) were returned to their original locations. Three cats (0.8%) died postoperatively. On average, 21.9% of the cats were pregnant during the TNRs, and the highest percentage of cats (63.9%) were pregnant in March. All cats presented to the TNR program were considered healthy enough to be part of the program after examination. For neutering one animal at a time, similar to conventional TNR ($140), it took 53 ± 16 mins for females and 30 ± 9 mins for males from anesthesia to recovery. In contrast, the standardized procedure can neuter multiple cats simultaneously, similar to the conveyor system, at an estimated rate of 6.8 mins per cat ($45 per female cat, $30 per male cat).ConclusionsThe TNR strategy in Seoul should be implemented by establishing dedicated clinics to concentrate on HQHVSN surgeries of cats. Through this pilot study, we were able to demonstrate that it is possible to effectively apply HQHVSN clinics in Korea. Future studies that perform intensive sterilization in targeted areas are necessary to confirm the efficacy of the TNR strategy.

An accessible scheme for monitoring free-roaming cat population trends.

Free‐roaming cats (FRCs) form nondomiciliary population groups that might lead to adverse environmental effects, as well as to welfare impairment of the cats themselves. Though criticized by ecologists, for the last two decades, the trap–neuter–return (TNR) programs were often employed aiming to manage these populations. At present, no accepted and accessible monitoring scheme exists to determine the effectiveness of those programs. In the current study, we present the reliability and validity of an applicable monitoring scheme, as an adjunct tool for a TNR program of FRC in an urban environment. The monitoring scheme is based on cat observation counts along randomly chosen transects. Fifty‐four transects were repeatedly walked for three years, between 2012‐2014, in 27 neighborhoods within an urban area of 19.3 Km2. Cat numbers counted in the 2014 observations were significantly higher than cat numbers found in the 2012 observations (prevalence ratio = 1.258, CI95%= 1.198–1.322, p < 0.001). The method revealed high reliability when different observers and different transects in the same neighborhood were compared (R 2 = 0.548 and R 2 = 0.391, respectively, for measuring cat counts per km, p < 0.001; and R 2 = 0.5 and R 2 = 0.74, respectively, for measuring neutering percentage, p < 0.001). This scheme was constructively validated by measurements of municipal data on the number of neutered cats and demonstrated high correlation (R 2 = 0.59, p < 0.001). Conducting cat observations using friendly calling and feeding resulted in an increased number of FRC observed per km walk (by 79% and 22%–30%, respectively). However, these manipulations did not alter the recorded percentage of neutered cats. The proposed scheme provides spatio‐temporal data that can contribute to the management programs of such cat metapopulations in an urban environment.

Back to School: An Updated Evaluation of the Effectiveness of a Long-Term Trap-Neuter-Return Program on a University's Free-Roaming Cat Population.

Simple SummarySince the early 1990s, the use of trap-neuter-return (TNR) as a humane alternative to the lethal management of stray and feral cats (also known as community cats) has expanded in the United States. Over this time, numerous studies have pointed to the effectiveness of TNR at reducing community cat numbers, although many of these investigations have covered relatively short time periods (3 years or less). A seminal paper by Levy et al. in 2003, documented a significant decline in community cat numbers on the campus of the University of Central Florida (UCF) over a 11-year period. Since 2017, a series of peer-reviewed articles have described other examples of long-term reductions in community cat numbers associated with TNR. The present study adds to this growing body of evidence by revealing the extent to which the results first reported by Levy et al. have been sustained over a subsequent 17-year period. After a total of 28 years, 10 (5%) of 204 total cats enrolled in the UCF TNR program, remain on campus and the campus community cat population has declined by 85% from the completion of an initial census in 1996 to 2019.A growing body of evidence indicates that trap-neuter-return (TNR) is not only effective at reducing community cat numbers, but that such reductions are sustainable over extended periods. Recently, a series of peer-reviewed articles documenting long-term declines in community cat populations associated with TNR have been published. The present study adds to this pool of evidence by updating and reexamining results reported from the campus of the University of Central Florida (UCF) in 2003 by Levy et al. From 1991 to 2019, a total of 204 cats were enrolled in a volunteer-run TNR program on the university grounds; 10 cats (5%) remained on site at the conclusion of the present study. The campus community cat population declined by 85% between 1996, the year an initial census (indicating the presence of 68 cats) was completed, and 2019. In addition, 11 of 16 total colonies were eliminated over a 28-year period. These results occurred despite significant growth in enrollment at UCF over the same time frame, which suggests that with sufficient ongoing management of colony sites, declines in community cat populations associated with TNR are sustainable over long periods and under varying conditions.

Incongruous killing: cats, nonhuman resistance, and precarious life beyond biopolitical techniques of making-live

ABSTRACT Under traditional programmes, unclaimed cats entering animal shelters were euthanized by barbiturate injection; since the implementation of Trap-Neuter-Return (TNR), cats are sterilised and returned to the streets. TNR cats are not only made to live – they are made to work for politics through a technique of tracking live releases from the shelter system to gain public support. However, biopolitical techniques are more than counting – life persists beyond the statistic. This paper traces the underexplored consequences of ‘nuisance wildlife’ removal laws in the ‘no kill’ era of TNR-only programmes in Miami. Trapped cats can be processed as ‘nuisance wildlife’, and killed by gassing, rather than by the only lawful method for killing cats in a shelter: lethal injection. How does TNR, created to make cats live, result in new vulnerabilities and incongruous cat deaths? This case study makes visible both known and unforeseen nonhuman vulnerabilities when biopolitical techniques are implemented without consideration for the complex systems of power at play within the apparatuses of nonhuman animal management. The precarious lives of cats suspended between wild and domestic, wanted and unwanted, and across political and legal purviews, requires greater engagement with the frameworks of killability for domestic and wild species.

A Long-Term Lens: Cumulative Impacts of Free-Roaming Cat Management Strategy and Intensity on Preventable Cat Mortalities.

This study used a previously developed stochastic simulation model (1) to estimate the impact of different management actions on free-roaming kitten and cat mortality over a 10-year period. These longer-term cumulative impacts have not been systematically examined to date. We examined seven management scenarios, including: (1) taking no action, (2) low-intensity removal, (3) high-intensity removal, (4) low-intensity episodic culling, (5) high-intensity episodic culling, (6) low-intensity trap-neuter-return (TNR), and (7) high-intensity TNR. For each scenario we tracked within the model the number of kittens born, the number of kittens surviving to adulthood, and the number of adults removed using lethal control over the entire 10-year simulation. We further defined all kitten deaths and lethal removal of adults as “preventable” deaths because they could potentially be reduced by certain management actions. Our simulation results suggested that the cumulative number of preventable deaths over 10 years for an initial population of 50 cats is highest for a “no-action” scenario, estimated at 1,000 deaths. It is lowest for a high-intensity TNR scenario, estimated at 32 deaths, a 31-fold difference. For all management scenarios tested, including removal and culling, the model predicted fewer preventable deaths than for a no-action scenario. For all management scenarios, the model predicted that the higher-intensity option (defined in terms of the proportion of animals sterilized or removed within a given time period) would result in fewer preventable deaths over time than the lower-intensity option. Based on these findings, we conclude that management intensity is important not only to reduce populations more quickly, but also to minimize the number of preventable deaths that occur over time. Accordingly, the lessons for the animal welfare community are both encouraging and cautionary. With sufficient intensity, management by TNR offers significant advantages in terms of combined lifesaving and population size reduction. At lower intensity levels, these advantages are greatly reduced or eliminated. We recommend that those who seek to minimize suffering and maximize lifesaving for free-roaming cats attempt to balance prospective goals (i.e., saving lives tomorrow) with proximate goals (i.e., saving lives today), and recognize that thoughtful choice of management strategies can ensure that both of these complementary goals are achieved.

A Case of Letting the Cat out of The Bag-Why Trap-Neuter-Return Is Not an Ethical Solution for Stray Cat (Felis catus) Management.

Simple SummaryTrap-Neuter-Return (TNR) is advocated as an effective, humane and ethical solution to problems caused by stray cats living in close association with human habitations. In Australia, TNR has previously been rejected by the Federal Government and the Australian Veterinary Association as an inappropriate management strategy for stray cats. Despite this, and public support for the control of cat numbers and legislative initiatives, calls persist for widespread trials of TNR. We review TNR literature that report empirical data to assess whether TNR resolves problems caused by stray cats and whether cats released under TNR would have a good quality of life. We identify ten ethical and welfare challenges that any cat control program must consider, particularly if cats are to be returned to urban environments. Simply, the weight of these data indicate that TNR cat management is unlikely to solve the problems in most cases and is unethical on animal welfare grounds. We argue instead for a holistic approach to reducing cat numbers using targeted adoption, early-age desexing and community education initiatives.Trap-Neuter-Return (TNR) programs, in which stray cats are captured, neutered and returned to the environment are advocated as a humane, ethical alternative to euthanasia. We review the TNR literature in light of current debate over whether or not there should be further TNR trials in Australia. We revisit the problems arising from stray cats living in association with human habitation and estimate how many stray cats would have to be processed through a scientifically-guided TNR program to avoid high euthanasia rates. We also identify 10 ethical and welfare challenges that have to be addressed: we consider the quality of life for stray cats, where they would live, whether the TNR process itself is stressful, whether TNR cats are vulnerable to injury, parasites and disease, can be medically treated, stray cats’ body condition and diet, and their impacts on people, pet cats, and urban wildlife, especially endemic fauna. We conclude that TNR is unsuitable for Australia in almost all situations because it is unlikely to resolve problems caused by stray cats or meet ethical and welfare challenges. Targeted adoption, early-age desexing, community education initiatives and responsible pet ownership have greater promise to minimize euthanasia, reduce numbers rapidly, and address the identified issues.