Crested shelduck

The crested shelduck (Tadorna cristata), or Korean crested shelduck, is a species of bird in the family Anatidae. It is critically endangered. The male crested shelduck has a greenish-black crown, breast, primaries, and tail, while the rest of its face, chin, and throat are brownish black. The male's belly, undertail coverts, and flanks are a dark grey with black striations. The upper wing coverts are white, while its speculum is an iridescent green. The female has a white eye ring, black crest, white face, chin, throat, neck, and uppers wing coverts and a dark brown body with white striations. Additionally, both sexes have a distinctive green tuft of feathers protruding from the head.

Very little is known about this species because of the limited number of observations of it. It apparently breeds in Korea and eastern Russia and is probably a relict species that had a wider distribution in prehistoric times. Some think that this species is extinct, although occasional sightings are reported, including a number of reports made between 1985 and 1991 from the interior wetlands of China. Due to the persistent reports of the species' survival, it is listed as critically endangered. However, the crested shelduck has not been definitively sighted since 1964.