TNR programs, especially when paired with socialization and adoption, can successfully reduce stray and feral cat populations over the long term.

A growing body of research suggests well-managed trap-neuter-return (TNR) programs can achieve sustained reductions in the number of stray and feral cats in a given area. Earlier studies showing the promising results of TNR programs looked only at short-term data, making their predicted success somewhat tentative. But a new study published in the journal Animals shows that these positive results can be maintained over the long term with careful management and a concerted adoption program.

The study examined the success of a TNR program that has been running for nearly three decades on the University of Central Florida (UCF) campus. The study compared the results of the program during its initial period of operation (from 1996 to 2002) with updated data collected over the intervening 17 years (from 2002 to 2019). They found the campus community cat population had declined by a total of 85% since the program began in 1996, with continuous reduction year after year.

The results of this program had initially been examined in a study published in 2003. That study showed the volunteer-run enterprise had achieved a significant reduction in the campus cat population during its initial decade of operation. So, the authors of the present paper wanted to see if the program remained as successful nearly two decades later.

What they found is encouraging: The initial 66% reduction observed from 1996 to 2002 persisted into the future. From 2002 to 2019, the number of stray and feral cats declined an additional 57%. This suggests maintaining long-term TNR programs may be worthwhile, as such programs can continue achieving positive results for decades.

However, the long-term success of a TNR program may require more than just sterilization. While the main premise of the TNR approach is population reduction by breeding prevention, the success of the program on the UCF campus is not wholly attributable to biology. Coordinated adoptions accounted for a substantial portion of the decrease in the community cat population, even among cats categorized as feral. This required a concerted effort by volunteers to socialize the feral cats and, if adoption appeared to be a suitable option for them, to coordinate their placement in loving homes.

Other factors that contributed to the long-term success of the program at UCF included prompt sterilization of new cats as they were discovered on campus, as well as careful placement of feeding stations in areas where students and faculty did not often notice them and thus wouldn’t think to abandon their own unwanted cats on campus. (Abandonment is a significant contributor to the growth of community cat populations. Although TNR programs have been shown to completely eliminate kitten births in a colony within two to eight years, population numbers can remain relatively steady due to the arrival of cats from elsewhere—including due to human abandonment.)

While TNR programs initially arose as a solution to concerns over wildlife, public health issues, and nuisance complaints, this paper explains they can also improve the overall welfare of community cats themselves. For instance, the paper suggests that preventing feral kitten births can reduce suffering considerably, since expected mortality among free-roaming kittens is as high as 75%. And by socializing feral cats so that they may become suitable for adoption, a well-rounded TNR program can provide forever homes for cats whose fates are otherwise much more uncertain.

In sum, despite the considerable work that goes into running a successful long-term TNR program, this paper suggests the benefits can be well worth it. For animal advocates, the study is yet another piece of evidence showing why such programs deserve our support.