korean species bird family critically endangered extinct male greenish black crown breast tail rest face chin throat brownish black male belly flanks dark grey black upper wing white green female white eye ring black crest white face chin throat neck wing dark brown body white additionally sexes distinctive green feathers protruding head little known bird limited number observations species apparently breeds korea eastern russia probably species wider distribution prehistoric times think species extinct occasional sightings reported including number recent reports interior wetlands china persistent reports species survival listed critically endangered definitively sighted taxonomy initially collected april near russia described english zoologist decided specimen possible hybrid duck pair collected korea male presented japanese noted plumage specimens definitively intermediate suggested parents alleged hybrid female collected given supported specimens bird clearly hybrid historical record species japan described bird female designated preserved male collection member family species considered distinct merit genus placed genus includes species genus comes celtic word means essentially english specific epithet comes latin word species common derived green feathers head species known korean korean korean description sexually male possessing greenish black crown breast tail rest face chin throat brownish black male belly flanks dark grey black upper wing white green female large white eye ring black crest white face chin throat neck upper wing dark brown body white sexes green feathers protruding head centimetres long slightly larger bill legs pinkish female paler male bill male small like base plumage immature unknown distribution habitat collected near russia near korea proposed species breeds far eastern russia northern north_korea northeast china winters southern japan southwest korea east china coast far south shanghai believed range widespread historic times species believed live wide variety wetland deep water habitats varying elevations collected individuals coast especially near river mouths recently number reports interior wetlands northeastern china speculated species breed mountainous areas away water volcanic lakes ecology behavior known believed migratory traveling siberia breeding season korea southern russia japan winter believed eat aquatic vegetation agricultural crops algae invertebrates crustaceans garbage suggested nocturnal nest described similar nest suggested species nest tree proposed species lays eggs female believed breed july observed flocks birds conservation numerous modern times thought widespread historically presence japanese species known handful sightings declared extinct female shot sighting bird reported near building hopes species persisted group birds females male sighted russian students near small flock ducks reported north_korea northeast coast reported eastern russia severe doubts accuracy record recent survey chinese hunters resulted number unconfirmed reports northeastern china example chinese forest worker claimed ate unconfirmed reports region believe flock flock believed species survives likely fewer individuals species threatened extinction habitat loss hunting attempt gather reports species raise awareness prevent hunters consuming species distributed russia japan china south_korea north_korea resulting report north_korea record distributed northeastern china garnered reports species follow surveys area failed find threatening destroy potential habitat area historic records relationship humans duck collected korea exported japan known korean duck captured japan portrayed japanese work old chinese portray duck similar appearance claimed japanese hunters hunting species korea 1920s specimens exist museums male specimen kept female collection tokyo male collected mouth female collected near december female specimen described collected near april displayed today kept copenhagen additional specimens known existed lost female collected sole male given friend collector subsequently vanished additionally chinese hunter offered specimen professor professor realize rare bird turned appeared postage stamp
Crested shelduck