Get free weekly insights that help you understand your cat better.
A 16-year TNR program on the San Francisco Bay reduced the initial population of 175 cats by 99.4%, with only 1 cat remaining
Source: PMC / Frontiers (2020)
Source
The Impact of Targeted Trap-Neuter-Return Efforts in the San Francisco Bay AreaPMC / Frontiers (2020)
Notes
258 total cats enrolled between 2004-2020; only 1 remained at end. Source is peer-reviewed PMC article.
PMC / Frontiers. (2020). The Impact of Targeted Trap-Neuter-Return Efforts in the San Francisco Bay Area. As cited in Cat Cognition. https://catcognition.com/statistics/feral-cats/#tnr-sf-bay-16-year-results
82% mean reduction
TNR in a Chicago neighborhood decreased colony populations by a mean of 82% from peak, with 8 of 20 colonies completely eliminated
Alley Cat Allies Research (2023)
30-40 million
The estimated number of community cats (strays and ferals) in the US is 30-40 million
HumanePro (Humane Society) (2025)
95% sterilization rate
Córdoba, Spain achieved 95% sterilization rate of community cats through TNR from 2020-2024, projecting 55% population reduction by 2028
Alley Cat Allies (2025)
29%
Approximately 29% of the American public feed outdoor cats they don't consider their own pets (range: 15-47% depending on study)
HumanePro (Humane Society) (2025)
