The moustached kingfisher (Actenoides bougainvillei), also called Bougainville moustached kingfisher, is a species of bird in the family Alcedinidae. It is endemic to Bougainville Island in Papua New Guinea. An estimated 250–1,000 mature individuals are left.
Their natural habitats are subtropical or tropical, moist, lowland forests and subtropical or tropical, moist, montane forests; they nest in tree holes. They are threatened by habitat loss and introduced predators.
The Guadalcanal moustached kingfisher was previously lumped together with A. bougainvillei, but is now regarded as a separate species. It was first described in 1904, and in the late 1930s, a dozen specimens were collected in southern Bougainville. In 1941, A. b. excelsus was described on the basis of a single specimen from Guadalcanal, and later in 1953, two more specimens were obtained. In 2015, a male specimen was collected by a team from the American Museum of Natural History.
It inhabits lowland forest and hill forest in southern Bougainville, and hill and mist forest between 550 m and 1250 m of altitude in Guadalcanal.
In the 1950s, local people observed holes in the riverbanks or in the ground in the forest, which were thought to be the nests of moustached kingfishers. However, they are believed to be opportunistic cavity nesters. source