Brunei Darussalam (B), Indonesia (B), Malaysia (B).
Mountains of northern Borneo, recorded on Mt Mulu (north-eastern Sarawak), Mt Murud (north-eastern Kalimantan) and Mt Kinabalu (western Sabah).
 
Population
Estimated population is 2,500 - 9,999 (2010) and decreasing.
Status VU
Habitat loss, degradation and fragmentation due to conversion to agriculture is the main threat.
For more information see BirdLife International Species Factsheet.
Food
Snakes, lizards.
Voice
A 'huit huit huit huiit hwoooo', the first notes brief leading into a long, slurred last note.
Mountain Serpent Eagle (Spilornis) [XC158318]
by Peter de Rouw from Mount Kinabalu, Jalan Kinabalu, Sabah, Malaysia (call)
Mountain Serpent Eagle (Spilornis) [XC496128]
by id from Mt Kinablau, Malaysia (call)
Subspecies
Taxonomic status uncertain. Sometimes regarded as subspecies of Crested Serpent-Eagle (Spilornis cheela), but apparently does not intergrade with sympatric subspecies pallidus of Crested Serpent-Eagle (Spilornis cheela). Also altitudinally segregated and vocalizations quite different.
Similar Species
Crested Serpent-Eagle (Spilornis cheela) which is smaller, paler with shorter wings and narrower, less distinct greyish-white band on tail.
References
See References.