The use of trap-neuter-return (TNR) as a method of managing free-roaming cat populations has increased in the United States in recent decades. Historically, TNR has been conducted most often at a grassroots level, which has led to inconsistent data collection and assessment practices. Consequently, a paucity of analyzable data exists. An initiative is underway to standardize TNR program data collection and assessment. However, it could be some time before scientifically sound protocols are implemented on a broad scale. In the interim, sets of data collected by nascent citizen scientists offer valid opportunities to evaluate grassroots TNR programs. The purpose of the present study was to examine the effectiveness of a TNR program conducted by a citizen scientist located in Chicago, Illinois, where a county law permitting TNR was enacted in 2007. Colony populations, when grouped by the number of years enrolled in the program, declined by a mean of 54% from entry and 82% from peak levels. Results from coexistent TNR programs in the Chicago area are consistent with these findings.

The use of trap-neuter-return (TNR) as a humane alternative to the lethal management of free-roaming cats has been on the rise for several decades in the United States; however a relative paucity of data from TNR programs exists. An iconic community-wide TNR effort; initiated in 1992 and renowned for having eliminated hundreds of free-roaming cats from the Newburyport; Massachusetts waterfront; is cited repeatedly; yet few details appear in the literature. Although the presence of feline population data was quite limited; a detailed narrative emerged from an examination of contemporaneous reports; extant TNR program documents; and stakeholder testimony. Available evidence indicates that an estimated 300 free-roaming cats were essentially unmanaged prior to the commencement of the TNR program; a quick reduction of up to one-third of the cats on the waterfront was attributed to the adoption of sociable cats and kittens; the elimination of the remaining population; over a 17-year period; was ascribed to attrition. These findings illuminate the potential effectiveness of TNR as a management practice; as well as call attention to the need for broad adoption of systematic data collection and assessment protocols.

Available evidence indicates that overall levels of feline intake and euthanasia at U.S. shelters have significantly declined in recent decades. Nevertheless, millions of cats, many of them free-roaming, continue to be admitted to shelters each year. In some locations, as many as 70% of cats, perhaps up to one million or more per year nationally, are euthanized. New approaches, including return-to-field (RTF) and targeted trap-neuter-return (TNR) appear to have transformative potential. The purpose of the present study was to examine changes in feline intake and euthanasia, as well as additional associated metrics, at a municipal animal shelter in Albuquerque, New Mexico, after institutionalized RTF and targeted TNR protocols, together referred to as a community cat program (CCP), were added to ongoing community-based TNR efforts and a pilot RTF initiative. Over the course of the CCP, which ran from April 2012 to March 2015, 11,746 cats were trapped, sterilized, vaccinated, and returned or adopted. Feline euthanasia at the Albuquerque Animal Welfare Department (AAWD) declined by 84.1% and feline intake dropped by 37.6% over three years; the live release rate (LRR) increased by 47.7% due primarily to these reductions in both intake and euthanasia. Modest increases in the percentage of cats returned to owner (RTO) and the adoption rate were also observed, although both metrics decreased on an absolute basis, while the number of calls to the city about dead cats declined.

For decades, animal shelters in the U.S. have sought to reduce the number of cats that are impounded and euthanized. Since the 1990s, low-cost sterilization campaigns aimed at owned cats have achieved varying levels of success in meeting these objectives. Over a similar time period, the use of trap-neuter-vaccinate-return (TNVR), as a humane alternative to the lethal management of stray and feral cats, has proliferated. Because of the limited scope of many TNVR programs, the impacts of such efforts on shelter metrics have often proven difficult to measure. In the past decade, two new variants of TNVR, return-to-field (RTF) and high-impact targeting, have exhibited the capacity to contribute to significant reductions in shelter intake and euthanasia. The present study examines changes in feline intake and euthanasia, as well as impacts on associated metrics, at municipal shelters located in six diverse U.S. communities after integrated programs of RTF and targeted TNVR (collectively termed “community cat programs,” CCPs) were implemented. A total of 72,970 cats were enrolled in six 3-year CCPs, 71,311 of whom (98%) were sterilized, vaccinated, and returned to their location of capture or adopted. A median reduction of 32% in feline intake, as well as a median decline of 83% in feline euthanasia occurred across the six CCPs; median feline live-release rate increased by 53% as a result of these simultaneous declines in cat admissions and euthanasia. The integration of RTF and targeted TNVR protocols appears to result in greater feline intake and euthanasia reductions than programs lacking such an integrated approach.

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.

The recently published article, ‘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,’ by Crawford et al. warrants rebuttal. The case presented in the paper, opposing the initiation of TNR trials in Australia, ignores peer-reviewed evidence which substantiates the effectiveness of TNR at reducing unowned urban cat numbers. In addition, the paper’s authors offer a number of unrealistic recommendations, which are little more than a rebranding of the failed status quo. Urban stray cats have long been considered a problem across Australia. Current practice calls for the trapping and killing of thousands of healthy urban stray cats and kittens each year with no apparent effect on the total population. In contrast, the literature offers numerous examples, including two recent studies in Australia, of reductions in urban stray cat numbers where TNR has been implemented. TNR has also been associated with reduced feline intake and euthanasia at shelters, which improves both animal welfare and the well-being of shelter staff. A large-scale trial of TNR in an urban Australian context is scientifically justified and long overdue.