Domestic, feral and wild describe different histories

A 2023 landscape-genomics study examined the consequences of releasing domestic game-farm mallards into wild populations. It identified ongoing hybridization in parts of Europe and North America. Domestic ancestry can therefore enter a population whose birds live outside captivity and look much like wild mallards. Appearance and location do not by themselves establish genetic history.

The study also found that self-sustaining feral populations in New Zealand and Hawaii had differentiated from their original stock and showed evidence of local adaptation. Feral means descended from domestic animals while living outside ordinary domestic management; it does not mean unchanged genetically or incapable of responding to natural selection. These results concern particular mallard-derived populations, not every domestic duck breed. They explain why conserving domestic breed diversity and protecting wild waterfowl ancestry are related but distinct tasks, especially where releases bring the two into contact.