Ferality is observed in many crop species wherein individuals of the cultivated crop reproduce successfully and establish a self-perpetuating population in natural or semi-natural habitats.  Feral populations can evolve to differ from their parent populations and lose traits associated with domestication including for example, a lack of seed dormancy.  Hybridization between wild and cultivated forms of cropped species may facilitate ferality.  If GM plants become feral, they can establish populations in natural and semi-natural environments and act as both a source and sink for novel traits.  The presence of novel traits may facilitate the persistence of feral populations if the novel trait confers a selective advantage (e.g., drought tolerance, salinity tolerance, pest and disease resistance), but there is no evidence yet that transgenesis per se facilitates ferality.  In some cases and in some jurisdictions, the introduction of GM crops will require assurances of effective segregation and novel trait confinement.  The existence of feral crop populations can make novel trait confinement more difficult.  Monitoring and management of feral populations will be required for effective novel trait confinement.