"Trap-neuter-release, commonly referred to as TNR, is the only method proven to be humane and effective at controlling feral cat population growth. Using this technique, all the feral cats in a colony are trapped, neutered and then returned to their territory, where caretakers provide them with regular food and shelter."
"A nonlethal sterilization method to reduce the numbers of feral cats in the environment both immediately and for the long term. A comprehensive, ongoing program in which stray and feral cats already living outdoors in cities, towns and rural areas are humanely trapped, then evaluated, vaccinated and sterilized by veterinarians."
Feral cat - Literally “gone wild,” a domestic cat that was lost or abandoned and has reverted to a wild state, or a cat that was born outside to a stray or feral mother and had little or no human contact. Adult feral cats usually cannot be tamed and are not suited to living indoors with people. They live outside in family groups called colonies that form near a source of food and shelter. Feral cats can survive almost anywhere and are found worldwide.
TNR was brought to the U.S. from Europe and the U.K. during the 1980s. The practice of TNR grew rapidly in the '90s when Alley Cat Allies began providing information and assistance to people caring for feral cats who recognized that their numbers must be controlled and reduced through sterilization. In communities where TNR is widely embraced, feral cat numbers have dropped. TNR programs operate largely or entirely through the dedicated efforts of committed volunteers. TNR works because it breaks the cycle of reproduction. In general, the cost of sterilizing and returning a feral cat is less than half the cost of trapping, holding, killing and disposing of a feral cat. TNR protects public health and advances the goal of reducing the numbers of feral cats in the environment. The public supports humane, nonlethal TNR as the long-term solution to feral cat overpopulation.
Feral cat colony - A group of freeroaming cats living in a specific geographic area. Prior to the implementation of TNR, feral cat colonies consist of both stray (tame) and feral (wild) cats of all ages, from kittens through adults. After TNR is completed, a feral cat colony consists exclusively of feral adults.
Feral cat caregiver - A compassionate human who feeds feral cats, performs TNR and provides long-term care and monitoring for adult feral cats that are returned. Caregivers are men and women of all ages from all walks of life. Most of the leading feral cat organizations were founded by caregivers whose commitment to feral cats grew to encompass entire communities.
Stray cat - A domestic cat that strayed from home and became lost or was abandoned. Because a stray cat was once a companion animal, he or she can usually be resocialized and placed in an adoptive home.
(This information and more is located on the Alley Cat Allies Web site. Click on their link in the right column.)