Swan Goose

The swan goose is a large, long-necked goose, wild birds being 81–94 cm long, the longest Anser goose, and weighing 2.8–3.5 kg or more. The sexes are similar, though the male is larger with a proportionally longer bill and neck. The upperparts are greyish brown with thin light fringes, and there is a maroon hindneck and cap reaching just below the eye. The wingspan is 160–185 cm (Wikipedia, general species account).

It breeds in inland Mongolia, north-east China and the Russian Far East, is migratory, and winters mainly in central and eastern China. Vagrants occur in Japan, Korea and more rarely elsewhere in Asia, including Thailand. It forms small flocks outside the breeding season. Domestic breeds are introduced and feral in many places outside its natural range (Wikipedia, general species account).