Mountain Serpent-Eagle Spilornis kinabaluensis Scientific name definitions

c. 51–58 cm 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ; wingspan 118–129 cm 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close . Large-headed, broad-winged 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close dark serpent-eagle; differs from S. cheela in darker overall coloration, longer wings and markedly different vocalizations. Larger, longer-winged 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close and darker than sympatric S. cheela pallidus, and has more distinct and whiter central tailband 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ; Nisaetus alboniger is all black above, with longer, unmarked crest, and black and white below 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close . Female is slightly larger than male 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close . Bare parts entirely yellow 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close . Juvenile is presumably similar to that of S. cheela, but apparently undescribed 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close .

Montane and submontane evergreen forests; tendency to prefer ridgetop forest. Occupies higher altitudes (mostly between 1500 m and 2500 m 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ) than sympatric S. cheela pallidus, which inhabits adjacent lowlands. Recorded down to 1000 m on Kinabalu 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close . Overall altitudinal range 750–2900 m 2 Mann, C. F. (2008). The Birds of Borneo: An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union, and British Ornithologists’ Club, Peterborough. Close .

Apparently sedentary.

Particularly snakes and lizards; diet generally similar to that of S. cheela.

Reportedly similar to S. cheela, but distinctive 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close . High-pitched whistles ; described calls are a single plaintive long-drawn "hiiiíííiii", not unlike call of Giant Pitta (Hydrornis caeruleus), and a complex call of three rather soft short "kwick" notes followed immediately by "kele" (first syllable slightly lower) and long-drawn "liffliíííiiii" 3 van Balen, S. (1998). Note on the distribution of the Kinabalu Serpent-eagle with a first record for Kalimantan. Kukila. 10: 154-156. Close .

Nest and eggs unknown, but adults with two fledged young observed in Crocker Range in early Nov 2 Mann, C. F. (2008). The Birds of Borneo: An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union, and British Ornithologists’ Club, Peterborough. Close .

VULNERABLE. CITES II. Very small range, and probably small population likely decreasing because of continuing habitat loss and degradation. From assessment of known records, descriptions of abundance and range size, BirdLife International puts global population of mature individuals in band 2500–9999, approximating to 3500–15,000 individuals in all. Confined to mountains of N & C Borneo in Brunei, Sabah, Sarawak and Kalimantan. Observations in 1980s and 1990s suggest that this species is genuinely scarce, although much of its potential range is visited only infrequently by ornithologists, and it may be more widespread than currently indicated. Thought likely to occur more or less continuously from Mt Kinabalu S along Crocker Range to Ulu Padas, Gunung Mulu and border mountains of Brunei, and on Gunung Murud; S limits of range not well known, but reported in Kalimantan from Kayan Mentarang and, in Nov 2007, from Gunung Menyapa 4 Brickle, N. W., J. A. Eaton, and F. E. Rheindt (2010). A rapid bird survey of the Menyapa mountains, East Kalimantan, Indonesia. Forktail 26:31–41. Close , the latter considerably farther S than all previous known records. Principal threats facing this species are destruction, degradation and fragmentation of habitat, especially towards its lower elevational limits, where agricultural expansion and intensification have led to fairly rapid reduction in extent of forest cover; even at higher altitudes forest is under threat, here by, for example, smallholder agriculture. Rates of logging and land clearance, spreading from lower altitudes up into montane habitat occupied by this raptor, suggest that its numbers are likely to be decreasing, although rate of population decline has not been estimated. Proposed conservation actions include fieldwork to determine the species’ full range (especially its S & W limits) and population size, and the precise degree of threat which it faces from habitat destruction. This raptor occurs within Kinabalu and Mulu National Parks and Temburong/Kuala Belalong National Park (Brunei), and evidently also in Pulong Tau National Park (Gunung Murud). There is a need for further sites in Bornean highlands to be established as protected areas, and some guarantee should be sought that key protected areas for the species will be managed effectively. Research on its biology also highly desirable.