Any of various large aquatic birds of the family Anatidae chiefly of the genera Cygnus and Olor, having webbed feet, a long slender neck, and usually white plumage.
天鹅：鸭科的各种大型水禽，主要是天鹅和哑天鹅属，有蹼足、长而细的脖子和通常为白色的羽毛。
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Researches on stopover during migration of Anatidae birds were carried at Yellowriver wetland, freshwater lake areas in Yulin city and Hanjiang river in winter from 1998 to 2003.
"If it looks like a duck, and quacks like a duck, we have at least to consider the possibility that we have a small aquatic bird of the family Anatidae on our hands," said Rose, quoting Douglas Adams.