The term feral refers to any type of animal or plant that was once domesticated but has now reverted to the wild. Domesticated animals become feral when they are released, abandoned or if they escape from human captivity. A feral animal not only include the once domesticated individuals but also any offspring the animals may have or will produce after they have become feral.
Most feral animals in any particular region arrive there due to human activity. In order for them to become feral they must be able to survive in the habitat independently. For this reason exotic pets do not normally survive long enough to be deemed feral.
Feral animals commonly include livestock such as goats and pigs and house pets like dogs and cats. When these animals are left to fend for themselves they almost always cause a problem either for people or the natural environment that they have come to inhabit. These feral animals are known as invasive species when they impact the environment and/or pests when they become a problem for their estranged human companions.
Feral cat populations may very well be the most abundant form of invasive species in the world. Cats, which were once endemic only to Africa, have made their way to every continent in the world. Currently there are only a few small islands that do not have cats inhabiting them.
Because of their success at reproducing, feral cats make up large groups which are called feral cat colonies. These colonies can become extremely numerous. Although avoiding of human contact, feral cats often congregate near restaurants, dumpsters and residential garbage cans in search of leftovers; a burden felt by many who have to deal with them. In addition, a feral cat colony often becomes to large to support each member and the cats become ill from starvation and disease.
Many animal advocacy groups work with municipalities and others to reduce feral cat populations in a humane way. Some of their strategies include rehabilitation of fierce feral cats to prepare them for adoption, catching and neutering feral cats to reduce future populations and then relocating them to an area where they will have a lesser impact.
Feral goats are another animal that is considered destructive and dangerous to the environment in countries where they have been introduced such as Australia and Ecuador’s Galapagos Islands. With few natural predators, feral goats reproduce profusely and ravage the unique vegetation in the ecosystems. This not only endangers plant life but also the native animals that rely on the vegetation for sustenance which are not able to successfully compete with the goats. These countries have implemented progressive strategies to eradicate feral animals in their conservation efforts.