|Scientific Name:||Hylobates lar (Linneaus, 1771)|
|Infra-specific Taxa Assessed:|
Hylobates albimana (Vigors & Horsfield, 1828)
Hylobates longimana (Schreber, 1774)
Hylobates variegates (É. Geoffroy Saint-Hilaire, 1812)
Hylobates varius (Latreille, 1801)
|Taxonomic Notes:||This species forms a narrow area of sympatry and hybridization with H. pileatus in Khao Yai National Park, central Thailand (Brockelman 1978; Brockelman and Gittins 1984; Marshall and Brockelman 1986; Marshall and Sugardjito 1986), and with H. agilis in northern Peninsular Malaysia (W. Brockelman pers. comm.). Until at least 1925, an area of sympatry apparently existed in the region of Sriracha, about 80 km southeast of Bangkok. Therefore, a large zone of overlap in the distribution of H. lar and H. pileatus may originally have existed. In most parts of this hypothetical zone, gibbon habitat appears to have been destroyed, with the Khao Yai Park possibly representing the last remnant of the once large contact zone (Geissmann 1991). These zones demonstrate that reproductive isolation between the species is incomplete, although they do not freely interbreed in the wild where they are in contact (Brockelman and Gittins 1984).
The subspecies of Hylobates lar, although numerous and well-distributed latitudinally, are not highly distinct, in general. They are based largely on relatively minor body color variation and the degree of polychromatism of the fur (Brockelman 1985, 2004; Groves 2001; Woodruff 2005) The validity of H. l. yunnanensis as a subspecies is doubtful; it requires comparison with H. l. carpenteri (C. Groves and T. Geissmann pers. comm.). The only geographically well-separated subspecies is H. l. vestitus, which is found on Sumatra; despite its (relatively recent) isolation, however, it is not highly distinct phenotypically (W. Brockelman pers. comm.). The taxonomic status of all the H. lar subspecies, and specifically yunnanensis, requires further investigation.
|Red List Category & Criteria:||Endangered A2cd ver 3.1|
|Assessor(s):||Brockelman, W. & Geissmann, T.|
|Reviewer(s):||Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)|
This species is listed as Endangered as it is believed to have undergone a decline of more than 50% in the last three generations (45 years) due to rampant forest loss and loss of mature individuals due to hunting.
|Previously published Red List assessments:|
|Range Description:||The species as a whole is found in northern Sumatra (Indonesia), throughout Peninsular Malaysia (except for a narrow strip between the Perak and Mudah Rivers, where H. agilis occurs), north through southern and eastern Myanmar (east of the Salween River), most of Thailand (though not in the north-east), and marginally into southern China. The break in distribution between Perak and Muda/Thepa Rivers on the Malaysian Peninsula is genuine (T. Geissmann pers. comm.). The species also occurs in a small area of northwestern Lao PDR (west of the Mekong River). The range formerly extended into southeastern Thailand, where it was parapatric with H. pileatus (Brockelman 1978; Marshall and Sugardjito 1986; Marshall et al. 1972; T. Geissmann pers. comm.). It is unclear whether the population on Phuket (Thailand) is native, but they certainly have been introduced or reintroduced. |
In China, the species is currently known only from Nangunhe Nature Reserve in the Prefectury of Lincang, south-west Yunnan (Geissmann et al. 2006).
Native:Indonesia (Sumatera); Lao People's Democratic Republic; Malaysia (Peninsular Malaysia); Myanmar; Thailand
Possibly extinct:China (Yunnan - Native)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Population densities for this species range from 2.4 groups/km2 in Ketambe, Sumatra (Palombit 1992) to 0.7-2.6 groups/km2 in Kuala Lompat and Tanjong Triang on the Malayan peninsula (Ellefson 1974; MacKinnon and MacKinnon 1980; Raemaekers 1977) to 6.5 groups/km2 in Khao Yai National Park, Thailand (Brockelman cited in Chivers 2001). A few smaller, fragmented populations survive in southern Peninsular Thailand and northwestern Malaysia, perhaps together numbering in the low thousands. There are no recent estimates of the populations in the Tenasserim section of Myanmar, northern Sumatra and in southern Peninsular Malaysia (W. Brockelman pers. comm.).|
In China, during the 1960s, there were estimated to be 200 individuals on both sides of the Nangunhe River. In 1988, the date of last sighting, it was estimated that there were less than 10 groups. And in 1992, the last survey date, the authors did not find any direct evidence for the species' persistence, but estimated that three groups may remain with about 10 individuals in total. Although not specified in the original publications, this estimate appears to be based on interview data (Geissmann et al. 2006; Guo and Wang 1995; Lan and Wang 2000).
No population estimates are currently available for Indonesia, Malaysia, and Myanmar. While for Lao PDR, there are no reliable estimates, but for Nam Poyi National Protected Area (which is the only protected area from which they are recorded), the species is uncommon to rare, perhaps numbering in the mid- to high-hundreds (Boonratana 1997). In some parts of Thailand there are several populations where numbers are at least in the thousands, though in northern Thailand they are now very rare. The largest population is in Kaeng Krachan National Park, which probably has on the order of 3,000-4,000 individuals. The Western Forest Complex may well have on the order of 10,000 animals, and likely upwards of 1,000 survive in the western part of Khao Yai National Park, as well as in Phukhieo Wildlife Sanctuary and Nam Nao National Park. A few smaller populations survive in the south, for example Khao Sok (W. Brockelman pers. comm.).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This species is found in evergreen, semi-evergreen, and mixed evergreen-deciduous forest (sometimes known as "dry evergreen" forest, in the northern parts of its range), and is known to utilize regenerating secondary forest and selectively logged forest (Johns 1985). In northwestern Thailand, white-handed gibbons utilize patches of dry evergreen, mixed deciduous, and bamboo forest near Karen settlements if they are not hunted (Yimkao and Srikosamatara 2006). This is predominantly a lowland species (below 1,000-1,500 m).|
Like most other species of gibbon they consume a largely frugivorous diet that includes mainly figs, as well as young shoots, leaves, some flowers, and insects. Gibbons, unlike most macaques and leaf monkeys that often share their habitats, swallow nearly all the seeds that they ingest, making them potentially important as seed dispersers. Certain species of fruits that require the consumer to remove a tough outer cover appear to rely almost entirely on gibbons for seed dispersal (Bartlett 1999; Ellefson 1974; Gittins and Raemaekers 1980; MacKinnon and MacKinnon 1980; Palombit 1992, 1997; Ungar 1995).
Generation length in white-handed gibbons is on the order of 15 years. They mature late, with females maturing at 8-10 years and males at 8-12 years, and have one offspring every 3 to 5 years (Brockelman et al. 1998; W. Brockelman pers. comm.). If a female loses a baby she may come into estrus sooner, but the average inter-birth interval in a population at carrying capacity is about 3.5 years (W. Brockelman pers. comm.). Average group size in H. lar generally increases with latitude, illustrating that group size is not a very useful species-specific character in gibbons. This reflects a general trend of increasing birth rate with latitude found in many vertebrate groups. Average group size has been reported at 2.7 (Chivers 1978) and 3.3 (Ellefson 1974) in Peninsular Malaysia, 3.7 in central Thailand (Brockelman and Srikosamatara 1993), and 4.4 (Carpenter 1940) and 4.9 (Yimkao and Srikosamatara 2006) in northern Thailand. The average home range sizes are 44-54 ha on the Malayan peninsula (Ellefson 1974; Gittons and Raemaekers 1980; MacKinnon and MacKinnon 1980) and about 16 ha in the Khao Yai National Park in Thailand (Chivers 1984).
The major threat to this species is hunting (having replaced even forest clearance as the top threat); they are hunted both for subsistence food use and for the pet trade. Hunting pressure varies across the range, but takes place even within protected areas. Much of the hunting is done by villagers exploiting Aquilaria spp. trees prized for their aromatic wood, and other forest products (W. Brockelman pers. comm.).
Construction of roads through protected areas (for example, the Security Highway through Nam Poyi in Lao PDR, the north-south highway in Peninsular Malaysia) may also pose a threat since it promotes forest clearance and strip development, possibly increases fragmentation, and increases access by hunters into protected areas. Ongoing localized forest loss due to shifting agriculture and commercial plantations of palm oil poses a threat. On northern Sumatra, most of the lowland forests have been logged out and the threat of Ladia Galaskar, a network to link the west and east coasts of Aceh province, means that much of the remaining forest is at risk.
Hylobates lar, like all gibbons, is a nationally protected species in all the countries across its range, and is listed under CITES Appendix I. In most of its range it is confined to protected conservation areas (for example in Thailand, where no significant populations survive outside of protected areas). However, in most countries, these areas are not well patrolled, even if they are well managed for tourism. There is an urgent need for improved protection of these areas, ideally involving local communities that should benefit from as well as participate in management. Illegal use of forest products, as well as poaching, is common in most protected areas. Inadequate management and protection, rather than forest destruction, are the main long-term threats and conservation efforts must seek to identify the hunters and incorporate them into new management priorities.
Further survey work is needed to determine current population numbers within protected areas across the range. One such priority area is southwest Yunnan, where it is unclear whether the species still survives (W. Brockelman pers. comm.).
Anonymous. 1995. More on Thai gibbon PHVA. Asian Primates 4(4): 8-10.
Bartlett, T. 1999. Feeding and ranging behavior of the white-handed gibbon (Hylobates lar) in Khao Yai National Park, Thailand. Ph.D. Thesis, Washington University.
Bartlett, T. 2003. Intragroup and intergroup social interactions in white-handed gibbons. International Journal of Primatology 24: 239-259.
Bennett, E. and Caldecott, J. 1989. Primates of Peninsular Malaysia. In: H. Lieth and M. Werger (eds), Tropical rain forest ecosystems, Amsterdam.
Berkson, G. and Chaicumpa, V. 1969. Breeding gibbons (Hylobates lar entelloides) in the laboratory. Laboratory Animal Care 19: 808 - 811.
Bhumpakphan, N. 1988. Ecology of white-handed gibbon (Hylobates lar) and Phayre's langur (Presbytis phayrei) in Huai Kha Khaeng Wildlife Sanctuary. M.Sc. Thesis, Kasetsart University.
Boonratana, R. 1997. Field training in wildlife conservation research techniques and large mammal survey at Nam Phui National Biodiversity Conservation Area, Lao PDR. Vientiane. IUCN/LSFP.
Brockelman, W. 1978. Preliminary report on relations between the gibbons Hylobtes lar and H. pileatus in Thailand. In: D. Chivers and K. Joysey (eds), Recent advances in primatology, vol.3: Evolution, London, UK and New York, USA.
Brockelman, W. 1985. A gibbon pelt (H. lar entelloides) from Khao Yai National Park, Saraburi Province, Thailand. Natural History Bulletin of the Siam Society 33: 55-57.
Brockelman, W. 1994. PHVA workshop: learning to help the gibbons of Thailand. Primate Conservation 15: 58-63.
Brockelman, W. 2004. Inheritance and selective effects of color phase in white-handed gibbons (Hylobates lar) in central Thailand. Mammalian Biology 69: 73-80.
Brockelman, W. and Gittins, S. 1984. Natural hybridization in the Hylobates lar species group: Implications for speciation in gibbons. In: H. Preuschoft, D. Chivers, W. Brockelman and N. Creel (eds), The lesser apes. Evolutionary and behavioural biology, Edinburgh.
Brockelman, W. and Srikosamatara, S. 1993. Estimation of density of gibbon groups by use of loud songs. American Journal of Primatology 29: 93-108.
Brockelman, W. Y., Reichard, U., Treesucon, U. and Raemaekers, R. J. J. 1998. Dispersal, pair formation and social structure in gibbons (Hylobates lar). Behavioral Ecology and Sociobiology 42(5): 329–339.
Carpenter, C. 1940. A field study in Siam of the behavior and social relations of the gibbon (Hylobates lar). Comparative Psychology Monographs 16(5): 1-212.
Chivers, D. 1978. The gibbons of peninsular Malaysia. Malayan Nature Journal 30: 565 - 591.
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. 2001. The swinging singing apes: Fighting for food and family in far-east forests. In: Chicago Zoological Society (ed.), The apes: Challenges for the 21st century. Brookfield Zoo, May 10-13, 2000, Conference Proceedings, pp. 1-28. Chicago Zoological Society, Brookfield, Illinois.
Chivers, D. and Davies, G. 1979. The abundance of primates in the Krau Game Reserve, peninsular Malaysia. Miscellaneous Series, Department of Geography, University of Hull 22: 9–36.
Ellefson, J. 1968. Territorial behavior in the common white-handed gibbon, Hylobates lar Linn. In: P. Jay (ed.), Primates: Studies in adaptation and variability, New York, USA.
Ellefson, J. 1974. A natural history of white-handed gibbons in the Malayan Peninsula. In: D. Rumbaugh (ed.), Gibbon and Siamang, vol. 3, Basel and New York.
Geissmann, T. 1991. Sympatry between white-handed gibbons (Hylobates lar) and pileated gibbons (H. pileatus) in southeastern Thailand. Primates 32(3): 357–363.
Geissmann, T. 1995. Gibbon systematics and species identifications. International Zoo News 42: 467-501.
Geissmann, T., Traber, S. and von Allmen, A. 2006. Das Nangunhe-Naturreservat, Provinz Yunnan, China: Ein Projektbericht [Nangunhe Nature Reserve, Yunnan Province, China: A project report]. Gibbon Journal 2: 14-17.
Gittins, S. and Raemaekers, J. 1980. Siamang, lar and agile gibbons. In: D. Chivers (ed.), Malayan forest primates – Ten years' study in tropical rain forest, pp. 63-105. Plenum Press, New York, USA.
Groves C. 2001. Primate Taxonomy. Smithsonian Institution Press, Washington, DC, USA.
Groves, C. P. 1968. A new subspecies of white-handed gibbon from northern Thailand, Hylobates lar carpenteri new subspecies. Proceedings of the Biological Society of Washington 81: 625–628.
Guo, G. and Wang, Z. 1995. Survey on the white-handed gibbon in Nangunhe valley in China. Chinese Primate Research and Conservation News 4(2): 7-9.
Johns, A. 1985. Behavioral responses of two Malaysian primates (Hylobates lar and Presbytis melalophos) to selective logging: vocal behaviour, territoriality, and nonemigration. International Journal of Primatology 6: 423-433.
Johns, A. 1996. Effects of selective logging on the behavioural ecology of West Malaysian primates. Ecology 67: 684-694.
Kanwutanakid, C. 2000. Characteristics of fruits consumed by the white handed gibbon (Hylobates lar) in Khao Yai National Park, Thailand. M.Sc. Thesis, Mahidol University.
Kawamura, S. 1958. A preliminary survey of the white-handed gibbon in Thailand. Primates 1: 157-158.
Kawamura, S. 1961. A pilot study on the social life of white-handed gibbons in northwestern Thailand. Nature and Life in Southeast Asia, Kyoto 1: 159 - 169.
Lan, D. and Guo, G. 1995. Present status on conservation of primates in Lincang district of Yunnan. Chinese Primate Research and Conservation News 4(2): 4-7.
Lan, D. and Wang, Z. 2000. Wildlife conservation in Nanguanhe River Nature Reserve: A preliminary survey. Tiger Paper 27: 24-28.
MacKinnon, J. and MacKinnon, K. 1978. Comparative feeding ecology of six sympatric primates in West Malaysia. In: D. Chivers and J. Herbert (eds), Recent advances in primatology, vol. 1: Behaviour, pp. 305-321. Academic Press, London, UK and New York, USA.
MacKinnon, J. and MacKinnon, K. 1980. Niche differentiation in a primate community. In: D. Chivers (ed.), Malayan forest primates: Ten years' study in tropical rain forest, pp. 167-190. Plenum Press, New York, USA.
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, J. and Brockelman, W. 1986. Pelage of hybrid gibbons (Hylobates lar x H. pileatus) observed in Khao Yai National Park, Thailand. Natural History Bulletin of the Siam Society 34: 145-157.
Marshall, J. and Marshall, E. 1976. Gibbons and their territorial songs. Science 193: 235–237.
Marshall, J., Ross, B. and Chantharojvong, S. 1972. The species of gibbons in Thailand. Journal of Mammology 53: 479-486.
Marsh, C. and Wilson, W. 1981. A survey of primates in peninsular Malaysian forests. Final report for the Malaysian Primates Research Programme, July 1981. Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
Ma, S. and Wang, Y. 1986. The taxonomy and distribution of the gibbons in southern China and its adjacent region – with description of three new subspecies. Zoological Research 7(4): 394–410.
Mootnick, A. 2006. Gibbon (Hylobatidae) species identification recommended for rescue or breeding centers. Primate Conservation 21: 103 - 138.
Nettelbeck, A. 1993. Zur Öko-Ethologie freilebender Weisshandgibbons (Hylobates lar) in Thailand. Diploma Thesis, Zoologisches Institut und Museum, Universität Hamburg.
Nettelbeck, A. 1998. Encounters between lar gibbons (Hylobates lar) and binturongs (Arctictis binturong). Folia Primatologica 69: 392-396.
Nettelbeck, A. 1998. Observation on food sharing in wild lar gibbons (Hylobates lar). Folia Primatologica 69: 386-391.
Nettelbeck, A. 2003. On the social behaviour of wild immature white-handed gibbons Hylobates lar (Linnaeus, 1771). Ph.D. Thesis, Universität Hamburg.
Neudenberger, J. 1993. Monogamie als Paarungssystem: Eine Fallstudie am Weisshandgibbon (Hylobates lar) im Khao Yai Nationalpark, Thailand. Diploma Thesis, Georg-August Universität.
Palombit, R. 1992. Pair bonds and monogamy in wild siamang (Hylobates syndactylus) and white-handed gibbon (Hylobates lar) in northern Sumatra. Ph.D. Thesis, University of California.
Palombit, R. 1993. Lethal territorial aggression in a white-handed gibbon. American Journal of Primatology 31: 311-318.
Palombit, R. 1995. Longitudinal patterns of reproduction in wild female siamang (Hylobates syndactylus) and white-handed gibbons (Hylobates lar). International Journal of Primatology 16: 739-760.
Palombit, R. 1996. Pair bonds in monogamous apes: A comparison of the siamang Hylobates syndactylus and the white-handed gibbons. Hylobates lar Behaviour 133: 321-356.
Palombit, R. 1997. Inter- and intraspecific variation in the diets of sympatric siamang (Hylobates syndactylus) and lar gibbons (Hylobates lar). Folia Primatologica 68: 321-337.
Raemaekers, J. 1977. Gibbons and trees: Comparative ecology of the siamang and lar gibbon. Ph.D. Thesis, University of Cambridge.
Raemaekers, J. 1984. Large versus small gibbons: Relative roles of bioenergetics and competition in their ecological segregation in sympatry. In: H. Preuschoft, D. Chivers, W. Brockelman and N. Creel (eds), The lesser apes. Evolutionary and behavioural biology, Edinburgh.
Reichard, U. 1991. Zum Sozialverhalten einer Gruppe freilebender Weisshandgibbons (Hylobates lar). Diploma Thesis, Georg-August-Universität.
Reichard, U. 1995. Extra-pair copulations in a monogamous gibbon (Hylobates lar). Ethology 100: 99-112.
Reichard, U. 1995. Sozial- und Fortpflanzungsverhalten von Weisshandgibbons (Hylobates lar): Eine Freilandstudie im thailändischen Khao Yai Regenwald. Ph.D. Thesis, Georg-August-Universität.
Reichard, U. 1997. Group encounters in wild gibbons (Hylobates lar): Agonism, affiliation, and the concept of infanticide. Behaviour 134: 1135-1174.
Reichard, U. 1998. Sleeping sites, sleeping places, and presleep behavior of gibbons (Hylobates lar). American Journal of Primatology 46: 35-62.
Reichard, U. and Sommer, V. 1994. Grooming site preferences in wild white-handed gibbons (Hylobates lar). Primates 35: 369 - 374.
Suwanvecho, U. 1997. Behavioral study of maturation of white-handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand. M.Sc. Thesis, Mahidol University.
Treesucon, U. 1984. Social develoment of young gibbons (Hylobates lar) in Khao Yai National Park, Thailand. M.Sc. Thesis, Mahidol University.
Tunhikorn, S., Brockelman, W., Tilson, R., Nimmanheminda, U., Ratanakorn, P., Cook, R., Teare, A., Castle, K. and Seal, U. S. 1994. Population and habitat viability analysis report for Thai gibbons: Hylobates lar and H. pileatus. IUCN / SSC Conservation Breeding Specialist Group, Apple Valley, Minnesota, USA.
Uhde, N. 1997. Das Raubfeindrisiko bei Gibbons (Hylobates lar) – Eine sozioökologische Studie im Regenwald des Khao Yai (Thailand). Diploma Thesis, Georg-August-Universität.
Uhde, N. and Sommer, V. 2002. Anti-predatory behaviour in gibbons (Hylobates lar, Khao Yai / Thailand). In: L. Miller (ed.), Eat or be eaten: Predatory sensitive foraging among nonhuman primates, Cambridge, UK.
Ungar, P. 1996. Feeding height and niche separation in sympatric Sumatran monkeys and apes. Folia Primatologica 67: 163 - 168.
Ungar, P. S. 1995. Fruit preferences of four sympatric Primate species at Ketambe, northern Sumatra, Indonesia. International Journal of Primatology 16(2): 221-245.
Vellayan, S. 1981. The nutritive value of Ficus in the diet of lar gibbon (Hylobates lar). Malaysian Applied Biology 10: 177-181.
Vimuktayon, P. 2001. The ecology of seed dispersal in wild rambutan (Nephelium melliferum) by white-handed gibbons (Hylobates lar) and other frugivores in Khao Yai National park, Thailand. M.Sc. Thesis, Mahidol University.
Whitington, C. 1990. Seed dispersal by white-handed gibbons (Hylobates lar) in Khao Yai National Park, Thailand. M.Sc. Thesis, Mahidol University.
Whitington, C. 1992. Interactions between lar gibbons and pig-tailed macaques at fruit sources. American Journal of Primatology 26: 61-64.
Whitington, C. and Treesucon, U. 1991. Selection and treatment of food plants by white-handed gibbons (Hylobates lar) in Khao Yai National Park, Thailand. Natural History Bulletin of the Siam Society 39: 111-122.
Woodruff, D., Monda, K. and Simmons, R. E. 2005. Mitochondrial DNA sequence variation and subspecific taxonomy in the white-handed gibbon, Hylobates lar. The Natural History Journal of Chulalongkorn University 1: 71–78.
Woodruff, D. S. 2005. Molecular genetic studies of gibbon phylogeny and phylogeography. The Natural History Journal of Chulalongkorn University 1: 114.
Yimkao, P. and Srikosamatara, S. 2006. Ecology and site-based conservation of the white-handed gibbon (Hylobates lar L.) in human-use forests in Mae Hong Son Province, northern Thailand. Natural History Bulletin of the Siam Society 54: 109-138.
|Citation:||Brockelman, W. & Geissmann, T. 2008. Hylobates lar. The IUCN Red List of Threatened Species 2008: e.T10548A3199623.Downloaded on 27 April 2018.|
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