Trap-Neuter-Return, 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.
TNR has many advantages; it immediately stabilizes the size of the colony by eliminating new litters. The nuisance behavior often associated with feral cats is dramatically reduced; including the yowling and fighting that come with mating activity and the odor of unneutered males spraying to mark their territory. The returned colony also guards its territory, preventing unneutered cats from moving in and beginning the cycle of overpopulation and problem behavior anew. Particularly in urban areas, the cats continue to provide natural rodent control.
Another significant advantage to TNR is that, when practiced on a large scale, it lessens the number of kittens and cats flowing into local shelters. This results in lower euthanasia rates and the increased adoption of cats already in the shelters. In fiscal year 2012 feral cat intake was down by 24% at our local Collier County Domestic Animal Services.
TNR is not just the best alternative to managing feral cat populations - it is the only one that works. Doing nothing has resulted in the current overpopulation crisis. Trying to "rescue" the cats and find them all homes is unattainable given their numbers and the futility of trying to socialize them. Trap and remove, the traditional technique exercised by animal control, is simply ineffective. If all the cats are not caught, then the ones left behind breed until the former population level is reached. Even if all the cats are removed, new unneutered cats tend to move in to take advantage of whatever food source there was, and the cycle starts again, this is called the "vacuum effect". This explains why more and more animal control agencies are willing to try TNR.
Finally, TNR is an idea whose time has come. It recognizes there is a new balance in our urban and rural landscape, one that includes feral cats. It seeks to manage this new population with enlightened techniques that allow the cats to live out their lives and fulfill their natures, while minimizing any possible negative impact. TNR is a movement that will continue to grow as more and more caring people see its potential and, in time, it will become the predominant method of feral cat management.