Feral

A feral () animal or plant is one that lives in the wild but is descended from domesticated individuals. As with an introduced species, the introduction of feral animals or plants to non-native regions may disrupt ecosystems and has, in some cases, contributed to extinction of indigenous species. The removal of feral species is a major focus of island restoration. A feral animal is one that has escaped from a domestic or captive status and is living more or less as a wild animal, or one that is descended from such animals. Other definitions include animals that have changed from being domesticated to being wild, natural, or untamed. Some common examples of animals with feral populations are horses, dogs, goats, cats, rabbits, camels, and pigs. Zoologists generally exclude from the feral category animals that were genuinely wild before they escaped from captivity: neither lions escaped from a zoo nor the white-tailed eagles re-introduced to the UK are regarded as feral. Domesticated plants that revert to wild are referred to as escaped, introduced, naturalized, or sometimes as feral crops. Individual plants are known as volunteers. Large numbers of escaped plants may become a noxious weed. The adaptive and ecological variables seen in plants that go wild closely resemble those of animals. Feral populations of crop plants, along with hybridization between crop plants and their wild relatives, brings a risk that genetically engineered characteristics such as pesticide resistance could be transferred to weed plants. The unintended presence of genetically modified crop plants or of the modified traits in other plants as a result of cross-breeding is known as "adventitious presence (AP)". Certain familiar animals go feral easily and successfully, while others are much less inclined to wander and usually fail promptly outside domestication. Some species will detach readily from humans and pursue their own devices, but do not stray far or spread readily. Others depart and are gone, seeking out new territory or range to exploit and displaying active invasiveness.