Trap, Neuter, Release (TNR) is advertised as a tool to reduce feral cat numbers. Unfortunately, TNR programs have been shown to fail to reduce feral cat populations while simultaneously maintaining feral cats on the landscape, where they contribute to wildlife and public health risks.
Trap, Neuter, Release (TNR) is a program by which feral cats are trapped, spayed or neutered, and then released into the environment. Rather than immediately reducing numbers through removal, TNR practitioners hope to slowly reduce populations over time.
The scientific evidence regarding TNR clearly indicates that TNR programs are not an effective tool to reduce feral cat populations. Rather than slowly disappearing, studies have shown that feral cat colonies persist and may actually increase in size.
TNR programs fail because they do not operate in an enclosed system and cannot spay or neuter a sufficient number of cats to affect feral cat numbers at the population level. Despite the good intentions of many involved in TNR programs, TNR has been found to be a waste of time, money, and resources.
For example, one evaluation of two long-term TNR programs in California and Florida indicated that “any population-level effects were minimal.” The team of researchers concluded that “no plausible combination of [conditions] would likely allow for TNR to succeed in reducing population size.”
Once feral cats are spayed or neutered, they are then abandoned back into the environment to continue a feral existence. Not only is this systematic abandonment inhumane to the cats, it perpetuates numerous problems such as wildlife predation, transmission of disease, and property destruction.