The mallards were once kept to hybrid many forms of domestic ducks, such as Peking duck in China, duck head duck in Italy, and green head duck in Japan.

• 绿头鸭曾被人利用饲育驯养而改良成各种的家鸭品种如中国的北京鸭、意大利的黑头鸭及日本的青头鸭等。