A feral cat colony is a local population of feral cats living in a specific location and using a common food source such as food scavenged from dumpsters or supplementary feeding by humans. Feral cat populations and colonies are located worldwide, including parts of the world where the domestic house cat is an introduced species, such as the Americas and Australia.

Those familiar with feral cats disagree on how many cats must be present for the population to be considered a "colony", with some who consider even a single feral cat that is regularly present at a site to be a colony, while others would require multiple cats to be present in a location at a higher density than the baseline population in surrounding areas.

Feral cat colonies form when irresponsible humans intentionally abandon their unsterilized pets or allow them to wander off, or if the pet escapes before planned sterilization. Colonies can also arise when changes in human activity create an opportunity for existing baseline feral cat populations to form a locally concentrated group. For example, the opening of a new restaurant and resulting presence of edible garbage can attract cats from the local population and allow them to breed and survive in larger numbers.

The feral colony around the Pantheon, Rome is given long legendary history at that location.

Colonies often considered a nuisance

When a feral cat colony grows to a large size, those living or working nearby might consider the presence of a locally concentrated cat population to be a nuisance. Specific concerns often include:

• Urine spraying to mark territory
• Digging in gardens and feces left by the cats
• Noise made by fighting and mating cats
• Predation upon wildlife
• Diseases transmissible to humans (zoonoses)
• Diseases transmissible to pets
• The poor state of health of the cats in the colony
• The likelihood of population growth

Those who consider feral cat colonies to be a nuisance traditionally have attempted to eliminate the colony, by requesting that municipal or private pest control services trap the cats and remove them (typically to be euthanized). However, if the factors that allowed the colony to develop in the first place (e.g. food resources) are not addressed as well, a new colony can form in the same location when cats that escaped trapping and cats from the surrounding area move in and breed.

"Managed" colonies

More recently, a number of animal welfare organizations have begun to employ the "Trap-Neuter-Return" (TNR) method to deal with the issue of feral cat colonies, sometimes with the support of local municipalities. This approach includes sterilization of the cats to prevent breeding, removal (and euthanasia of sick or injured cats), vaccination, marking, and return of healthy cats to the site, and rescue of kittens and other tame cats to adoptive homes. Groups promoting this approach believe that it addresses many of the concerns of those who might otherwise consider the colony a nuisance, and provides a palatable alternative for cat lovers who might otherwise take no action to prevent the population from growing.

A colony in which the TNR method is being used to sterilize the cats and that is under the regular care and observation of a caretaker is known as a managed colony.

Breeds arising from feral cat colonies

Two breeds of cat have been developed recently from feral cat populations. The Egyptian Mau was developed from Egyptian feral cat colonies in the 1950s. The American Keuda is being still developed from barn cat colonies in the US Southwest from the 1980s.

External links

• Alley Cat Allies, a feral cat advocacy organization