Five or six white ducks which swim about in winter amid the few remaining lotus stems in a pool at the Taipei Botanical Garden also share these "ancestral genes," and bird guides emphasize the upwards curl of the mallard's "upper tail coverts" as being one of the species 'distinguishing features.
冬日的台北市植物園裡，殘荷疏梗，五、六隻遭人放養的白鴨悠游穿梭，身上就留著祖先的「遺傳基因」，鳥類圖鑑也特別在介紹綠頭鴨時，強調它「尾上覆羽向上卷」，是賞鳥辨識的特點。