(I) Physical CharacteristicsThe mountain range of Trus Madi follows a major north-east-south-west trend and is strongly dissected into steep sided valleys and narrow-crested ridges. It is separated from Banjaran Crocker by the Tambunan-Keningau-Tenom plain. Banjaran Trus Madi forms the watershed between three of the largest rivers in Sabah State namely the Pagalan, Labuk and Kinabatangan. Gunung Trus Madi (2,642 m asl), the second highest mountain in Sabah State, is located this range. The mountain itself was formed from mudstone, shale and argillite mildly metamorphosed in places to slate with subordinate beds of quartzite, sandstone, siltstone and limestone breccias (Collenette, 1958 cited in Acres, 1972).
A total of 143 species of birds were identified in a survey in 1983 (Sheldon and Francis, 1985). The highlands is the second most important area for Bornean endemics and montane species after Kinabalu supporting globally threatened birds like the Mountain Serpent-eagle Spilornis kinabaluensis and the Near Threatened Bornean Frogmouth Batrachostomus mixtus (Smythies, 1999).
Non-bird biodiversity: Thirty-six species of mammals identified in a survey in 1983 (Payne and Francis, 1985; Sheldon and Francis, 1985). (I) Globally threatened mammals (IUCN, 2002): ENDANGERED: Mountain Spiny Rat Maxomys alticola; VULNERABLE: Smooth-tailed Treeshrew Dendrogale melanura, Pig-tailed Macaque Macaca nemestrina, Jentink's Squirrel Sundasciurus jentinki, Common Porcupine Hystrix brachyura; NEAR THREATENED: Brooke's Squirrel Sundasciurus brookei, Bornean Gibbon Hylobates muelleri, Long-tailed Macaque M. fascicularis, Pangolin Manis javanica; DATA DEFICIENT: Malayan Sun Bear Helarctos malayanus (II) Globally threatened reptiles (IUCN, 2002): No information.(III) Globally threatened plants (IUCN, 2002): CRITICAL: Nepenthes macrophylla; VULNERABLE: Nepenthes lowii
BirdLife International (2019) Important Bird Areas factsheet: Trus Madi Range. Downloaded from http://www.birdlife.org on 17/08/2019.