The red-billed diving duck (scientific name: Netta rufina), commonly known as the big redhead, is a large duck, the individual is smaller than the mallard duck, the body length is 45-55 cm, and the weight is about 1 kg. The male has a chestnut head and a pale brownish yellow crown. The upperparts are dark brown, the wing mirrors are white, and the mouth is reddish. The underbody is black, the two sides are white, the features are very obvious, and it is easy to identify in the wild. The female is brown throughout, with grayish-white sides of the head, the sides of the neck, and the chin and throat.
China mainly breeds in Inner Mongolia Wuliang Suhai, Xinjiang Tarim River Basin, Qinghai Qaidam Basin, etc., wintering in southern Tibet, Yunnan, Sichuan, Guizhou and other provinces in China.
Migration: Spring migration from the southern wintering grounds to breeding grounds such as northwestern And Inner Mongolia in the spring, and some do not arrive until the end of April and the beginning of May. Autumn begins its southward migration in late September and early October. Migrations are often grouped together.
The breeding season is from April to June. Nesting is usually formed when the wintering grounds are overwintered, and nesting begins when they arrive at the breeding grounds in mid-April. It usually nests on reed-and-grassy islands, in waterside grasses and unwater reeds, and sometimes in dry reed piles by the lake. Nests are dense, sometimes 6-7 nests can be found in a reed stack,