Trap-Neuter-Release (TNR) is a program wherein feral cats are humanely trapped, spayed or neutered and released back into their territory.
An unaltered female cat left alone to breed can produce two or three litters per year. Each of her offspring in turn can produce two or three litters per year and so on and so on. This cycle results in literally thousands of unwanted kittens in the community.
The only way to control the number of free-roaming cats and to prevent their suffering is to consistently spay and neuter.
Cities that have adopted TNR programs in their communities have seen a noticeable reduction not only in the number of cats in local colonies but also in the number of feral cats being relinquished to shelters.
Cats that have been spayed or neutered live healthier lives. Females are less likely to develop ovarian or uterine cancer; males are less likely to develop testicular cancer. Unaltered males have a tendency to fight during mating season; once neutered the urge to fight is eliminated, preventing injury and infection. Males that have been neutered will also often cease spraying which is a common complaint against feral cats.
You can find more information on feral cats by following the links below: