“One of the most common and popular practices among the general public for managing a feral colony is called Trap-Neuter-Return (TNR) (Orzechowski “New Survey Reveals Widespread Support for Trap-Neuter-Return.”). This practice often includes more than three steps, with those including: surveys and assessment, priority trapping, spay-abort operations, spay-fixing, vaccination, ear clipping, relocation, additional medical treatment, and population monitoring. The general purpose of TNR is to eliminate colonies over time through prevention of reproduction while being minimally invasive to the existing social structures within a colony and improving the quality of life for the trapped animals and their human neighbors through medical care. Additionally, this practice has a long history of use in the setting of university campuses as noted by the existence of a resource guide made by Alley Cat Allies (ACA “Cats on Campus: A Trap-Neuter-Return Program for Feral Cats.”). 

While the goal of TNR is straightforward and may seem like a clear choice for animal lovers given the similarly popular alternative of mass euthanasia, the outcomes of this practice have varied, but some literature reviews give an alarmingly negative report of its efficacy (Hostetler 8). 

In a review of studies evaluating the efficacy of primarily TNR practices, one study by renowned animal welfare researcher and doctor of veterinary medicine, Dr. Julie Levy, measured the efficacy of a long term TNR and adoption, the results of which indicate measurable success: “Trapping began in 1991; however, a complete census of cats was not completed until 1996, at which time 68 cats resided on site. At completion of the study in 2002, the population had decreased by 66%, from 68 to 23 cats (of which 22 were feral). No kittens were observed on site after 1995, but additional stray or abandoned cats continued to become resident. New arrivals were neutered or adopted before they could reproduce” (“Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population” 42). These results indicate the efficacy of the program, especially in the sense that reproduction had evidently ended since no kittens were observed in the latter half of the program. There are some issues however, with the conclusion that this is the most effective option, or really effective in any sense. 

For example, the majority of the cats that were not included in the colony’s final count were those that were adopted out, rather than those that died. In fact, the proportion of cats that were absent from the final survey that were euthanized was nearly double that of those who died naturally, indicating that a population of this size would take more than a decade of TNR alone for an entire feral colony to cease to exist through natural or accidental death. In this sense, we can see that TNR is ineffective on its own as a method of reducing feral cat populations, especially since while those populations persist, there often continues to be an influx of “new arrivals” (“Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population” 42).

In another study over a span of four years on the scale of multiple colonies across the general urban area of Córdoba, Spain, results were labeled as “promising” and “a scalable model for urban feline management”. In this study TNR alone was used and a population variability analysis model projected a 55% reduction in population by the year 2028 (8 years after the initiation of the program). From these data, we can see that much higher rates of success are possible, but they may require resources on a level that is not as accessible in many localities and to smaller institutions like a private university, such as VWU, compared to a large city like Córdoba (Luzardo et. al. 482).

The final study chosen for discussion is particularly applicable to this project as it was conducted on a university campus. For a period of two years from 1998 to 2000, Texas A&M implemented a trap-test-vaccinate-alter-return-monitor (TTVARM) program to manage their feral cat colony populations. This study had two promising outcomes; reproduction rates decreased as seen in fewer kittens captured from year one to year two, and human impact was also reduced: “The number of cat complaints received by the university's pest control service [also] decreased from Year 1 to Year 2” (Hughes and Slater 20). However, the success of this endeavor may also be attributed to the fact that more than 20% of the captured cats not accounted for in the final survey were removed from the campus by way of adoption rather than natural death (Hughes and Slater 20).

In discussing the benefits of TNR we must note that, while the levels of reported success are inconsistent, the evidence does still suggest that TNR reduces feral populations over time through the mitigation of reproduction. Additionally, the fact that many organizations practicing TNR provide medical care before releasing animals highlights another benefit of the approach: the neutering procedure is often paired with administering rabies vaccinations. For that reason, this strategy is endorsed by the CDC as a method of reducing risk of rabies transference from feral cats to humans (Ludmer et. al. 481). Upon understanding the myriad of benefits of TNR practices, it is clear why this is an aspect of my proposed solution. 

However, the benefits alone should not be the only thing we consider when deciding whether or not to employ this management strategy, but also the challenges and limitations. A literature review of the humanity and efficacy of TNR concluded that TNR is not viable in most situations and that there are much more humane methods of reducing feral cat populations, thereby making TNR inhumane by comparison (Hostetler 8). Additionally, according to the principles laid out in Darrell Huff’s book, How to Lie With Statistics, those studies that indicated measurable success could have had these results due to a manipulation of data or the exclusion of other variables despite their statements of unbiasedness, which calls into question the reliability of these claims in the evaluation of the efficacy of TNR (Huff How to Lie with Statistics).

Beyond the compounded challenges of resource availability, necessary duration of programs, and consistency of results, we must also view the efficacy of TNR through the lens of a social issue. Given that one of the appeals of TNR is that it is a middle ground between the highly effective practice of mass euthanasia and the public preference for not intervening in the lives of feral cats, it is important then to address whether it succeeds in satisfying an audience of varying priorities.

One study evaluating TNR from a conservationist perspective criticizes that current TNR practices is “based on a narrow, single-species approach to animal welfare”, indicating that this is not supported by those who prioritize conservation of native species over the individual lives of feral cats (Debrot et. al. 2022). Additionally, since the most effective reports of TNR practices are those that included other methods of population minimization, it is reasonable to conclude that TNR may be ineffective on its own. 

However, it is not just those who prioritize conservation with a preference for euthanasia that disapprove of the practice of TNR. Some of those who would prefer that these cats remain alive are opposed to this practice for an altogether separate reason; disapproval of fixing surgeries for male animals.

While this evidence points to a clear issue, the disapproval of neutering animals on the basis of personal bias and misinformation, we also have evidence to suggest that there is a solution to the misinformation. In order to assess this solution we can look to research centered on how the integration of TNR campaigns into a social framework caused change in behavior towards unowned cats. A study on the subject of changing perceptions towards TNR indicated that greater education and community outreach surrounding positive neutering practices made a measurable change in combative behavior and perception of TNR (McDonald 7).

The final note to be made about TNR is that its cost efficiency can vary. A study titled, “Guidance for management of free-roaming community cats: a bioeconomic analysis” describes the comparison between cost effectiveness of TNR and euthanasia, claiming that TNR is “a viable and potentially more cost-effective approach if performed at higher intensities over a sufficient duration” in comparison to euthanasia (Benka 984). This does not, however, mean that it is a viable solution for every instance of feral cat control, especially given that there are few funding resources and many of the organizations that perform sterilization procedures are non-profit organizations who rely largely on donations.”