Life in a feral cat colony is hard and tends to be short. While well-cared-for pet cats often live into their teens, a feral cat is lucky to survive beyond about three or four years. Diseases are common and spread rapidly. Nutrition is often inadequate, and as the colony grows there is less food for everyone.
Females weakened by continual breeding are particularly vulnerable and may die, leaving sick and abandoned kittens. Traffic accidents and fighting among rival toms lead to injuries and infections that never receive treatment.
Most countries now have a policy of managing feral cat colonies, both for humane reasons and to prevent them from becoming an environmental problem. As a more acceptable alternative to wholesale eradication, many cat rescue organizations or animal welfare societies have put a three-part program into practice.
This involves trapping the cats without causing injury, neutering them (and ear-tagging them for future identification), and returning them to the colony. Unfortunately, this often proves to be a temporary solution. The numbers of feral cats may fall for a time, but eventually unneutered cats will join the community and even a single breeding pair can restock the colony within a year.