(I) Physical CharacteristicsDanum Valley Conservation Area is located in eastern Sabah, near Lahad Datu. The protected area occupies much of the upper catchment of Sungai Segama and comprises mostly rugged terrain at between 150-1,000 m asl. It is also the best representation of a continuous transition of undisturbed lowland dipterocarp forest to highland forest in Sabah. Three major summits can be found within the area; Gunung Nicola (917 m asl) on the northern perimeter, Gunung Danum (1,093 m asl) in the centre and Gunung Tribulation (861 m asl) in the upper Segama highland to the south-west.Three main types of geological formation have been identified in the area; the Crystalline Basement, Chert-spellite and the Kuamut (Marsh and Greer, 1992 cited in Magintan, 2000). The Chert-spillite formations occur to the north of Sungai Segama. It is composed of metamorphic and ultrabasic rocks of the Upper Cretaceous to early Tertiary age. Most of the soils is represented by two associations; the Mentapok Association and the Bang Association. The Mentapok Association corresponds to the hilly-mountain landform of Danum Valley. These soils are derived mainly from basic and intermediate igneous rocks and consist of chromic and orthic luvisols, euthric cambisols nad lithosols (Wright 1975, cited in Magintan, 2000). The Bang Association developed over rocks of the Kuamut Formation.(II) Climatic ConditionsThe area experiences two monsoon seasons with a wetter period affected by the north-east monsoon (December-March) and a drier period by the south-east monsoon (May-October), with rainfall ranging from 2,000 mm to 3,300 mm. Temperatures range from 22.5oC to 30.9oC with annual high humidity (Norhayati et al., 2001).
The primary lowland dipterocarp forest in Danum Valley supports several important globally threatened species and a rich diversity of biome-related species. Over 275 species have been recorded (Kiew, 1976; Marsh 1995; Mohamed Zakaria bin Hussin 1992; Showler, 1992; WWFM, 1998; MacKinnon and Phillipps 1993; Sheldon et al., 2001). All hornbill species in Sabah are also present in the area. At least 9 endemics (Lambert 1993), three dependent on unlogged forest Black-throated Wren-babbler Napothera atrigularis, Bornean Wren-babbler Ptilocichla leucogrammica and Bornean Blue Flycatcher Cyornis superbus. Other Near Threatened species recorded are the Oriental Darter Anhinga melanogaster and Lesser Fish-eagle Ichthyophaga humilis (Kiew, 1976; Sheldon et al., 2001).
Non-bird biodiversity: One hundred and twenty species of mammals, 72 reptiles, 56 amphibians and 37 fishes have been identified (Kiew, 1976; Showler, 1992; Heydon and Bulloh, 1996; (Payne and Francis, 1985). Significant populations of 10 species of primates, including the Orang-Utan Pongo pygmaeus and Proboscis Monkey Nasalis larvatus are present. A small number of Sumatran Rhinoceros Dicerorhinus sumatrensis (probably less than 20 individuals) may be present in the area, making this one of only two or three such sites known in Borneo, a crucial refuge for their continued survival (WWF, 2002a). (I)Globally threatened mammals (IUCN, 2002): CRITICAL: Sumatran Rhinoceros Dicerorhinus sumatrensis; ENDANGERED: Asian Elephant Elephas maximus, Orang-Utan Pongo pygmaeus; Proboscis Monkey Nasalis larvatus; Bay Cat Catopuma badia, Otter-Civet Cynogale bennettii; VULNERABLE: Pig-tailed Macaque Macaca nemestrina; NEAR THREATENED: Bornean Gibbon Hylobates muelleri, Long-tailed Macaque M. fascicularis; DATA DEFICIENT: Malayan Sun Bear Helarctos malayanus, Hairy-nosed Otter Lutra sumatrana, Hose's Langur Presbytis hosei(II) Globally threatened reptiles (IUCN, 2002): No information.(III) Globally threatened plants (IUCN, 2002): CRITICAL: Parashorea malaanonan, Shorea johorensis; ENDANGERED: Shorea pauciflora, Dryobalanops lanceolata; VULNERABLE: Engelhardia danumensis, Aglaia laxiflora, Mangifera rufocostata
BirdLife International (2021) Important Bird Areas factsheet: Danum Valley Conservation Area. Downloaded from http://www.birdlife.org on 21/01/2021.