when was it last sighted?
1904
Choiseul pigeon
The last confirmed sighting was in 1904. 
please describe to me the choiseul pigeon It is an extinct species of bird in the pigeon and dove family, Columbidae.
wiki:9253304
Choiseul pigeon [SEP] Introduction
The Choiseul pigeon ("Microgoura meeki") is an extinct species of bird in the pigeon and dove family, Columbidae. It was endemic to the island of Choiseul in the Solomon Islands, although there are unsubstantiated reports that it may once have lived on several nearby islands. The last confirmed sighting was in 1904. Other common names were Solomons crested pigeon, Solomon Islands crowned-pigeon and Kuvojo. The Choiseul pigeon was monotypic within the genus Microgoura and had no known subspecies. Its closest living relative is believed to be the thick-billed ground pigeon, and some authors have suggested that the Choiseul pigeon may be a link between that species and the crowned pigeons.