Sometimes called Chinese Spot-billed Duck, this is one of the most common duck in Japan. Sexes are alike. This species was formerly considered a race of the Spot-billed Duck (Anas poecilorhyncha) now split under the name Indian Spot-billed Duck. The Indian bird has conspicuous red spots at the base of its bill which give this species its name. However, these spots are absent in the Eastern Spot-billed Duck seen here. Furthermore the two breed sympatrically in parts of China confirming that they are separate species.