The Mandarin Duck (Aix galericulata) belongs to the Anatidae of Anseriformes and is the only species of the Aix genus distributed in China (Ruan, 1995).
Intestinal adenocarcinoma have been also reported in a budgerigar {Melopsittacus undulatus), mandarin duck (Aix galericulata), gull, (3) and at the pylorus and ileocecal junction in chickens.
A variety of migratory birds, such as Mandarin ducks (Aix galericulata), cinereous vultures, bean geese (Anser fabalis), and white-fronted geese (Anser albifrons), fly from Russia to South Korea during the winter for the breeding season (4-6).