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 upper 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.

Taxonomy

thumb|left|Diagram depicting male and female plumage

The crested shelduck was initially collected in April 1877 near Vladivostok, Russia. However, it was not described until 1890 when the English zoologist Philip Lutley Sclater decided that the specimen was a possible hybrid between the ruddy shelduck (Tadorna ferruginea) and falcated duck (Mareca falcata). Around 1913, a pair was collected in Korea, and the male was presented to Japanese ornithologist Nagamichi Kuroda. The 1916 female was designated the holotype and preserved with the male in Kuroda's collection. A member of the family Anatidae, this species was considered distinct enough to merit its own genus by Kuroda, The specific epithet, cristata, comes from the Latin word for crested. The species' common name is derived from the tuft of green feathers from the shelduck's head. This species is also known as the Korean crested shelduck, Korean sheldrake, and Korean Mandarin. The male's belly, undertail coverts, and flanks are a dark grey with black striations. The upper wing coverlets are white, while its speculum is an iridescent green. The female has a large white eye ring, black crest, and white face, chin, throat, neck, and upper wing coverts. It also has a dark brown body with white striations. It is believed to have a relict range, or to have been more widespread in historic times.

This species is believed to live in a wide variety of wetland and deep-water habitats at varying elevations. It has been speculated that this species may breed in mountainous areas either away from water or on volcanic lakes. In 1943, a sighting of this bird was reported near Chungcheongbukdo, building hopes that the species persisted. Old Chinese tapestries also portray a duck similar in appearance to the crested shelduck. The male was collected at the mouth of the Geum River in 1913 or 1914, and the female was collected near Busan in December 1916. The female specimen described by Philip Lutley Sclater, collected by Lieutenant F. Irmininger near Vladivostok in April 1877, was displayed in 1894 by the Zoological Society of London and today is kept in the National Museum of Denmark in Copenhagen.

References

Works cited

  • BirdLife International factsheet
  • Shelducks of the World