Hylobates albibarbis

Taxonomy (Name)

Picture

Distribution, Range

This species is found in Kalimantan, Indonesia south of the Kapuas River and west of the Barito River (Marshall and Sugardjito 1986).

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Map

Country

Brunei Darussalam
Cambodia
China
Indonesia
Japan
Lao PDR
Malaysia
Myanmar
Mongolia
Philippines
Singapore
Republic of Korea
Thailand
Vietnam

Status

International Status

IUCN Red List Category

ENIUCN

Justification

This species is considered Endangered based on an estimated population reduction of over 50% when considering the past 30 years and projected future habitat change due to draining of peat swamps, logging and burning into the next 15 years (totalling 45 years which is approximately 3 generations). Where the species persists there is hunting and collection for the wildlife trade and for human consumption. A large part of the species range is in peat swamp ? an extremely threatened ecosystem. This species may qualify for Critically Endangered in the future if rates of habitat change increase, and thus should be carefully monitored. In addition, the effectiveness of the protected areas should be considered, as these areas seem to be strongholds for the species.

IUCN

CITES

Appendix IIUCN

CMS

National Status

Ecology Discription

Appearance

Habitat

The species is found in primary, secondary and selectively logged tropical evergreen forests, as well as peat swamp forest types (Buckley 2004; Buckley et al. 2006).

IUCN

Population size

This species is generally common in suitable habitat (J. Hon pers. comm.). A tentative estimate suggests a population size of 19,000 individuals within the mixed-swamp forest habitat subtype in Sabangau, representing one of the largest remaining continuous populations of this species (Buckley 2004; Buckley et al. 2006). Density estimates range from 7.4 individuals/km2 (2.16 groups/km2) in the logged peat swamp forest of the Sabangau catchment area of central Kalimantan (Buckley 2004; Buckley et al. 2006), and 8.7 individuals/km2 in primarily heath forest of Tanjung Puting National Park (Mather 1992), to 14.9 individuals/km2 in a dominantly mountain forest area of the Gunung Palung Reserve (Mitani 1990).

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Behavior

They are recorded from forests up to 1,200 m asl (V. Nijman pers. comm.) with densities decreasing at higher elevations. Average home range sizes of 28 ha and 45 ha were determined at Gunung Palung and the Sabangau catchment area, respectively (Buckley et al. 2006; Mitani 1990).

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Diet

These arboreal and diurnal primates are dominantly frugivorous, preferring fruits high in sugar, but will also eat immature leaves and insects.

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Reproduction

Threat

Major Threat(s)

This species was certainly affected by fires of 1990s and continuing deforestation (legal and illegal logging, draining of peat swamps, expanding oil palm plantations, etc), but no recent surveys are available on population trends. A large part of the species range is in peat swamp ? an extremely threatened ecosystem. From 2003-2004, Nijman (2005) observed 79 individuals in markets in Kalimantan. It is also hunted for human consumption.

IUCN

Conservation and Measurement

International

CITES, Appendix I.IUCN

National

Bornean white-bearded gibbons are protected throughout their range by Indonesian lawIUCN

Conservation law

Protected Area

They are found in a number of protected areas, including Bukit Baka ? Bukit Raya National Park, Ganung Palung National Park, and Tanjung Puting National Park.

IUCN

Other Coservation Projects

Citation

Buckley, C. 2004. Survey of Hylobates agilis albibarbis in unprotected primary peat swamp forest: Sebangau catchment area, central Kalimantan. M.Sc. Thesis, Oxford Brookes University.

Buckley, C., Nekaris, K. and Husson, S. 2006. Survey of Hylobates agilis albibarbis in a logged peat-swamp forest: Sabangau catchment, Central Kalimantan. Primates 47: 327-335.

Groves, C. P. 2001. Primate taxonomy. Smithsonian Institution Press, Washington, DC, USA.

Hirai, H., Wijayanto, H., Tanaka, H., Mootnick, A. R., Hayano, A., Perwitasari- Farajallah, D., Iskandriati, D. and Sajuthi, D. 2005. A whole-arm translocation (WAT 8 / 9) separating Sumatran and Bornean agile gibbons, and its evolutionary features. Chromosome Research 13: 123-133.

IUCN. 2008. 2008 IUCN Red List of Threatened Species. Available at: http://www.iucnredlist.org. (Accessed: 5 October 2008).

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.

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.

Mitani, J. 1987. Territoriality and monogamy among agile gibbons: Hylobates agilis. Behavioral Ecology and Sociobiology 20(4): 265-269.

Mitani, J. 1990. Demography of agile gibbons (Hylobates agilis). International Journal of Primatology 11(5): 411-425.

Nijman, V. 2006. Hanging in the balance. An assessment of the trade in orangutans and gibbons in Kalimantan, Indonesia. Kuala Lumpur: TRAFFIC South-east Asia. Petaling Jaya, Selangor, Malaysia.

Nijman, V. 2006. Trade in Bornean gibbons. Gibbon Journal 2: 33-36.

Short, J. 2004. A preliminary study of the great calls of female hybrid gibbons (Hylobates agilis x H. muelleri) at Barito Ulu, Central Kalimantan, Indonesia. M.Sc. Thesis, Oxford Brookes University.

Sugardjito, J. 1978. Behavioural ecology of the dark-handed gibbon, Hylobates agilis albibarbis, in Kalimantan Tengah, Indonesia (in Indonesian). Ph.D. Thesis, Universitas Nasional.

Sugardjito, J. 1988. Preliminary field observation on agile gibbon (Hylobates agilis) of Tanjung Puting National Park, central Kalimantan. Rimba Indonesia 22(1): 75-82.

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