The Bougainville Moustached Kingfisher is a poorly known kingfisher. A pair was located in a gully on Bougainville Island during a 2024 expedition.
Field notes from 2024 describe a juvenile with slightly more muted colors and a dark brown bill than the adults.
In September 2024, a pair was recorded in a gully at 1,350 m. The male sang only once or twice between 6:00 and 6:30 a.m. before dawn and was once seen on a perch about 2 m above the ground.
An extinction-risk assessment has not been added yet.