Feral
Domestic animals can breed with native, wild animals. This interbreeding can threaten the existence of the original wild population. Examples include the mallard duck, wild boar, the rock dove or pigeon, the Red Junglefowl (Gallus gallus) (ancestor of all chickens), carp, and salmon. Another example is the dingo, itself an early feral dog, which interbreeds with dogs of other origin. However it is unlikely that this will harm the ecosystems in which these dogs live and some regard the importance of this phenomenon as disputable. In some cases like rabbits, the interbreeding seems not to be noticed. There is much debate over the effect of interbreeding on changes to the genes of a wild species.