this species was only discovered in 1968, and is known only from one site, a lake in central Thailand where the species over-wintered. Where it occurred at other times of the year is unknown. The wintering flocks were gradually eliminated by trappers and there have been no records since 1980. The species is presumed extinct.
Photo taken at the natural history museum in the Chulalongkorn University in Bangkok, September 2006.
