Swan goose scientific name: Anser cygnoides: is a large waterfowl of the class Avian, Anatidae and Geese. The body length is about 90 cm and the weight is 2.8-5 kg. The mouth is black, the body color is light gray-brown, the top of the head to the back of the neck is dark brown, and the front neck is nearly white. From a distance, the top of the head and the back of the neck appear black, and the front neck is nearly white, with clear black and white with strong contrast.