The green-winged duck (scientific name: Anas crecca) is a small duck with a body length of 37 cm and a weight of about 0.5 kg. The mouth and feet are black. The male has a dark maroon color from head to neck, a wide green band on both sides of the head from the eye to the side of the neck, and the undertail coverts are black, and there are yellow triangular spots on each side, which are very eye-catching when swimming in the water.
The Chinese branch has recorded their appearance in guangdong south China, north China, Xinjiang, and Inner Mongolia, and yunnan dashanbao nature reserve has the most
Every year, it begins to migrate north from the wintering grounds in southern China, and from mid-to-late March to mid-April, it appears in large numbers in northeast and northern China, often in large groups of 40-50 or even hundreds. Flying fast, arranged in a line or 'V' shape, the wings are agitated very fast, making a 'whooshing' drum wing sound. Autumn migration begins in early and mid-September, reaches the Yangtze River Basin in mid-to-late September, and reaches the coastal area of Guangdong in early October. The peak period of migration is from the end of September to the end of October, and a small number of individuals remain in the northeast and north China to overwinter.
It breeds throughout the Palearctic Realm and overwinters in the south. Sexual maturity occurs at the first age, but not all of them participate in reproduction, and some do not begin to reproduce until the second age. Most pairs form during the winter overwintering period, while a few form pairs on the spring migration route. Nesting begins shortly after arriving at the breeding grounds. The breeding season is from May to July.