Why killing Feral Cats doesn't work
Eradication is the traditional method for feral cat control. Even though several studies show that eradication programs do not work. According to Louise Holton of Alley Cat Allies, this method has failed to reduce the feral cat population, but has increased euthanasia figures in the United States dramatically.
Cats are removed, but the food source -- rodents, dumpsters, etc. -- remains. Thus, the surviving cats have less competition for food. They will breed several times a year, quickly recolonizing. A study by Karl Zaunbrecher, DVM, published in The Journal of the American Veterinary Medical Association, also showed that removal creates a vacuum, which can be followed by an influx of an equal number of new cats. With the new cats, fighting and nuisance spraying increases as the new cats compete for a place in the community. In little time, you are back to square one.
Which brings us to the next question: What does work?