|Scientific Name:||Hylobates muelleri|
|Species Authority:||Martin, 1841|
|Infra-specific Taxa Assessed:|
|Taxonomic Notes:||This species hybridizes with H. albibarbis in a wide area of central Borneo (Marshall and Sugardjito 1986, Mather 1992). In addition, there are wide inter-grade zones between the three subspecies (Marshall and Sugardjito 1986).|
|Red List Category & Criteria:||Endangered A2cd ver 3.1|
|Assessor(s):||Geissmann, T. & Nijman, V.|
|Reviewer(s):||Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)|
The species is considered Endangered based on an estimated population reduction of over 50% over the past 45 years (3 generations) due to rampant habitat loss and over-utilization. Where the species persists there is hunting and collection for the wildlife trade and for human consumption.
|Range Description:||The species as a whole occurs throughout Borneo except for the southwest (where H. albibarbis is found), from the north bank of the Kapuas River clockwise around the island to the east bank of the Barito River (Groves 2001).
Hylobates muelleri muelleri
This taxon is found in southeast Kalimantan, Indonesia, approximately south of the Mahakam River and west of the Barito River (Groves 2001).
Hylobates muelleri funereus
This taxon is found in Brunei, Indonesia (Kalimantan) and Malaysia (Sabah and Sarawak). It ranges from the northeast of Borneo (Sabah) south to the Mahakam River and perhaps west to the Baram District and the IV Division of Sarawak (Groves 2001).
Hylobates muelleri abbotti
This taxon is found in Indonesia (Kalimantan) and Malaysia (Sarawak). It occurs north of the Kapuas River and east as far east as the Saribas District of Sarawak (Groves 2001).
Native:Brunei Darussalam; Indonesia (Kalimantan); Malaysia (Sabah)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is generally common in areas where good forest remains (J. Hon pers. comm.). Densities estimated using various techniques at three Indonesian sites ranged from 9-14.6 individuals/km2 at Kutai National Park, to 6.9-9.9 at Kayang Mentarang National Park, and 7.9-9.5 at Sungai Wain Protection Forest (Nijman and Menken 2005). Out of 11 studies on the effects of logging, 6 reported decline and 3 were neutral (Meijaard et al. 2005). Meijaard and Nijman (unpubl. data) conservatively estimate the total population to be approximately 250,000-375,000 individuals.|
|Habitat and Ecology:||The species is found in tropical evergreen forests of primary, selectively logged and secondary forest types. Mueller's gibbons are arboreal and diurnal, and frugviorous (preferring fruits high in sugar), but will also eat immature leaves and insects (Leighton 1987; Rodman 1978). They have been recorded from forests up to 1,500 m (Leighton 1987) or 1,700 m in Sabah (Yasuma and Andau 2000), with densities decreasing at higher elevations (V. Nijman pers. comm.). In Kutai National Park, average home range size was 36 ha (Leighton 1987).|
|Major Threat(s):||Deforestation and trade in illegal pets are the predominant threats, and in interior areas hunting is also a threat (Mejiaard et al. 2005; Nijman 2005). From 2003-2004, Nijman (2005) recorded 54 individuals in markets in Kalimantan. Much habitat is being lost due to expanding oil palm plantations and logging.|
|Conservation Actions:||This species is listed on CITES Appendix I. It occurs in a number of protected areas across its range, including Betung-Kerihun National Park, Bukit Baka Bukit Raya National Park, Kayan Mentarang National Park, Kutai National Park, Sungai Wain Protection Forest, Tanjung Puting National Park (Indonesia); Lanjak-Entimau Sanctuary, Semengok Forest Reserve (Malaysia) (Richardson pers. comm.).|
Bennett, E., Caldecott, J., Kavanagh, M. and Sebastian, A. 1987. Current status of primates in Sarawak. Primate Conservation 8: 184 - 186.
Bennett, E., Caldecott, J., Sebastian, A. and Kavanagh, M. 1986. Conservation status of Sarawak's primates. Primate Eye 29: 36 - 41.
Bennett, E. L. and Dahaban, Z. 1995. Wildlife response to disturbances in Sarawak and their implications for forest management. In: R. B. Primack and T. E. Lovejoy (eds), Ecology, conservation and management of South-East Asian rainforests, pp. 66-86. Yale University Press, New Haven, USA, and London, UK.
Bennett, J. 1989. The confiscated primate dilemma in Sarawak. Australian Primatology 4(1): 6-8.
Bennett, J. 1992. A glut of gibbons in Sarawak – is rehabilitation the answer? Oryx 26(3): 157-164.
Blouch, R. 2000. Primates. In: E. Soepadmo and P. Chai (eds), Development of Lanjak-Entimau Wildlife Sanctuary as a totally protected area, phase I and phase II, 1993-1999: Scientific report, pp. 150-159. International Tropical Timber Organization (ITTO), Yokohama, Japan, and Sarawak Forest Department, Malaysia, Kuching, Sarawak.
Caldecott, J. O. 1988. Hunting and Wildlife Management in Sarawak. IUCN Tropical Forest Programme, Gland, Switzerland and Cambridge, UK.
Chivers, D. 1984. Feeding and ranging in gibbons: A summary. In: H. Preuschoft, D. Chivers, D. W. Brockelman N. and Creel (eds), The lesser apes. Evolutionary and behavioural biology, Edinburgh.
Chivers, D. 1992. Socio-ecology and conservation of gibbons in South-east Asia, with special reference to Borneo. In: G. Ismail, M. Mohamed and S. Omar (eds), Forest biology and conservation in Borneo, Centre for Borneo Studies Publication No. 2, Kota Kinabalu.
Davis, D. D. 1958. Mammals of the Kelabit Plateau, northern Sarawak. Fieldiana Zoology 39(15): 119-147.
Davis, D. D. 1962. Mammals of the lowland rain forest of north Borneo. Bulletin of the National Museum of Singapore 31: 1-129.
Galetti, M. and McConkey, K. 1998. Black hornbill Anthracoceros malayanus following gibbons in central Borne. Ibis 140: 686 - 687.
Gallardo, E. and Rool, D. 1988. Gibbon rehabilitation in Borneo. IPPL Newsletter. 15(1): 14.
Groves, C. P. 2001. Primate taxonomy. Smithsonian Institution Press, Washington, DC, USA.
Harrison, T. 1966. The gibbon in west Borneo folklore and augury. Sarawak Museum Journal 14(28-29): 132-145.
Howell, D. J. 2003. The effects of human activity on primates and other large mammals in East Kalimantan, Indonesia. M.Sc. Thesis, Central Washington University.
Johns, A. 1992. Species conservation in managed forests. In: T. Whitmore and A. Sayer (eds), Tropical deforestation and species extinction, London, UK.
Lee, S. 1999. A study of some aspects on behaviour and feeding ecology of Bornean gibbon (Hylobates muelleri, Martin 1841) in Tawau Hills Park, Sabah, Malaysia. B.Sc. Thesis, University Malaysia Sabah.
Leighton, D. 1987. Gibbons: Territoriality and monogamy. In: B. Smuts, D. Cheney, R. Seyfarth, R. Wrangham and T. Struhsaker (eds), Primate societies, pp. 135-145. University of Chicago Press, Chicago, USA and London, UK.
Leighton, M. and Leighton, D. R. 1983. Vertebrate responses to fruiting seasonality within a Bornean rain forest. In: S. L. Sutton, T. C. Whitmore and A. C. Chadwick (eds), Tropical Rain Forest: Ecology and Management, pp. 181-196. Blackwell, Oxford.
MacKinnon, J., Hatta, G., Halim, H. and Mangalik, A. 1995. The Ecology of Kalimantan. Periplus, Singapore.
Marshal, J. T. and Sugardjito, J. 1986. Gibbon systematics. In: D. R. Swindler and J. Erwin (eds), Comparative primate biology: Systematics, evolution and anatomy, pp. 137-185. Alan Liss, New York, USA.
Marshall, A. 2004. Population ecology of gibbons and leaf monkeys across a gradient of Bornean forest types. Ph.D. Thesis, Harvard University.
Mather, R. 1992. Distribution and abundance of primates in northern Kalimantan Tengah: Comparisons with other parts of Borneo and peninsular Malasia. In: G. Ismail, M. Mohamed and S. Omar (eds), Forest biology and conservation in Borneo, Sabah Foundation, Kota Kinabalu, Malaysia.
Mather, R. 1999. A field study of hybrid gibbons in central Kalimantan, Indonesia. Ph.D. Thesis, Cambridge University.
McConkey, K. 2000. Primary seed shadow generated by gibbons in the rain forests of Barito Ulu, central Borneo. American Journal of Primatology 52: 13-29.
McConkey, K. 2005. Influence of faeces on seed removal from gibbon droppings in a dipterocarp forest in Central Borneo. Journal of Tropical Ecology 21: 117-120.
McConkey, K. 2005. The influence of gibbon primary seed shadows on post-dispersal seed fate in a lowland dipterocarp forest in Central Borneo. Journal of Tropical Ecology 21: 255-262.
McConkey, K., Aldy, F., Ario, A. and Chivers, D. 2002. Selection of fruit by gibbons (Hylobates muelleri x agilis) in the rain forests of central Borneo. International Journal of Primatology 23: 123-145.
McConkey, K., Ario, A., Aldy, F. and Chivers, D. 2003. Influence of forest seasonality on gibbon food choice in the rain forests of Barito Ulu, central Borneo. International Journal of Primatology 24: 19-32.
Medway, L. 1977. Mammals of Borneo: Field keys and an annotated checklist. Monographs of the Malaysian Branch of the Royal Asiatic Society, Kuala Lumpur, Malaysia.
Meijaard, E. , Sheil, D., Nasi, R., Augeri, D., Rosenbaum, B., Iskandar, D., Setyawati, T., Lammertink, M., Rachmatika, I., Wong, A., Soehartono, T., Stanley, S. and O'Brien, T. 2005. Life after logging: Reconciling wildlife conservation and production forestry in Indonesian Borneo. Center for International Forestry Research, Jakarta, Indonesia.
Mitani, J. 1984. The behavioral regulation of monogamy in gibbons (Hylobates muelleri). Behavioral Ecology and Sociobiology 15: 225-229.
Nijman, V. 2001. Forest (and) primates: Conservation and ecology of the endemic primates of Java and Borneo. Ph.D. Thesis, Tropenbos-Kalimantan Series Vol. 5, Tropenbos International.
Nijman, V. 2005. Hanging in the balance: An assessment of trade in orang-utans and gibbons on Kalimantan, Indonesia. TRAFFIC Southeast Asia, Petaling Jaya, Selangor, Malaysia.
Nijman, V. and Menken, S. 2005. Assessment of census techniques for estimating density and biomass of gibbons (primates: Hylobatidae). Raffles Bulletin of Zoology 53(1): 169-179.
Payne, J., Francis, C.M. and Phillipps, K. 1985. A field guide to the mammals of Borneo. The Sabah Society and WWF Malaysia, Kota Kinabalu and Kuala Lumpur, Malaysia.
Robbins, D., Chapman, C. and Wrangham, R. 1991. Group size and stability: Why do gibbons and spider monkeys differ? Primates 32: 301-305.
Rodman, P. 1973. Synecology of Bornean primates: I. A test for interspecific interactions in spacial distribution of five species. American Journal of Physical Anthropology 38: 655-659.
Rodman, P. 1973. Synecology of Bornean primates with special reference to the behavior and ecology of the orang-utan. Ph.D. Thesis, Harvard University.
Rodman, P. 1978. Diets, densities and distributions of Bornean primates. In: G. Montgomery (ed.), The ecology of arboreal folivores, Washington, DC, USA.
Suzuki, A. 1992. The population of orang-utans and other non-human primates and the forest conditions after the 1982-83's fires and droughts in Kutai National Park, East Kalimantan, Indonesia. In: G. Ismail, M. Mohamed, and S. Omar (eds), Forest biology and conservation in Borneo, Centre for Borneo Studies Publication, Kota Kinabalu.
Wilson, C. and Wilson, W. 1975. The influence of selective logging on primates and some other animals in east Kalimantan. Folia Primatologica 23: 245-274.
Yasuma, S. and Andau, M. 2000. Mammals of Sabah. Part-2. Habitat and ecology. Japan International Cooperation Agency and Sabah Wildlife Deparment, Kota Kinabalu and Kuala Lumpur, Malaysia.
|Citation:||Geissmann, T. & Nijman, V. 2008. Hylobates muelleri. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 29 July 2015.|