The black swan is a bird species belonging to the family Cynoglossidae in the order of geese. The black swan is covered with flocculent gray feathers on its back; The neck is slender and often curved into an elegant "S" shape; The beak is bright red with a "V" - shaped white discharge at the front end; The iris is reddish red, and the tarsus and fins are black. Its physical characteristics are that except for a small part of the primary feathers that are white, the rest of the body's feathers are bright and black, hence the name.

It is a widely distributed waterfowl of the duck family. Known for its bright green head in males and simple brown feathers in females. Medium in size, males are usually more prominent than females, with a distinct green crown and white neck ring, while females have a brown body with mottled patterns. It is an omnivorous animal that mainly feeds on aquatic plants, insects, small fish, and small aquatic animals. It breeds in many wetlands, lakes, and rivers in the northern hemisphere, especially in Europe and Asia. It is a migratory bird that flies from its breeding grounds to its wintering grounds every autumn. The migration route covers a vast area, sometimes even crossing continents.

Wild duck is a bird species belonging to the family Anatidae in the order Anseriformes. It is a general term for various wild ducks, commonly known as water ducks, reed ducks, and clam geese. The narrow definition of wild duck only refers to the mallard. Female wild ducks have a smaller body size, measuring 50-56 centimeters in length and weighing approximately 1 kilogram. They enjoy group activities and living in groups. In summer, they inhabit freshwater rivers, lakes, and swamps with abundant aquatic plants in small groups. During winter, they gather into flocks of over a hundred ducks. They have a wide and diverse diet, often feeding on small fish, shrimp, crustaceans, insects, as well as seeds, stems, leaves, algae, and grains of plants. Feathers have high economic value, are not wet, have a soft texture, and have good insulation properties.