Javan gibbon (Hylobates moloch)

Description

Javan gibbon fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Javan gibbon description

The silvery or Javan gibbon (Hylobates moloch) has long fluffy silver-grey fur ⁽²⁾, with darker markings on the chest and cap ⁽⁴⁾. It has long arms and legs, long fingers and reduced thumbs, all of which are adaptations for brachiation (swinging through the trees from arm to arm) ⁽²⁾. Males produce simple ‘hoot’ calls, whilst the calls of females are more variable, ending in a ‘bubble’. ⁽⁴⁾. Both sexes also give a ‘scream’ alarm call ⁽⁸⁾.

Also known as

moloch, silvery gibbon.

French

Gibbon Cendré.

Spanish

Gibón Ceniciento.

Size

Head-body length: 45 - 64 cm ⁽⁴⁾

Weight

5.9 kg ⁽⁴⁾

Javan gibbon biology

Gibbons are highly adapted for their arboreal lifestyle, feeding and sleeping in the trees; the long arms are used to throw themselves from tree to tree, easily covering gaps as wide as ten metres ⁽⁸⁾. Male and female Javan gibbons are monogamous, living in family groups with around four juvenile offspring who subsequently disperse ⁽⁸⁾. Group territories are actively defended by patrols, who engage in impressive bouts of loud calls and aggression ⁽²⁾.

Javan gibbon range

The Javan gibbon is endemic to the western half of the island of Java, Indonesia ⁽³⁾.

Javan gibbon habitat

Inhabits tropical lowland, hill and montane rainforests ⁽³⁾ between sea level and 1500 metres ⁽²⁾. The Javan gibbon shows a preference for taller trees for resting, foraging and locomotion ⁽³⁾.

Javan gibbon status

The Javan gibbon is classified as Endangered (EN) on the IUCN Red List ⁽¹⁾, and listed on Appendix I of CITES ⁽⁷⁾.

Javan gibbon threats

The Javan gibbon has undergone a dramatic population decline principally as a result of habitat destruction ⁽⁶⁾, and also from the trapping of juveniles for the pet trade ⁽²⁾. The native forests of Java have been cleared for logging, agriculture and development, and the species has declined to fewer than 1,000 individuals over the last 25 years ⁽⁴⁾. This gibbon appears to be on the very brink of extinction with only a handful of isolated viable populations remaining ⁽⁶⁾.

Javan gibbon conservation

In light of the status of this species in the wild, a Javan gibbon rescue and rehabilitation workshop was conducted in 1997 hosted by Conservation International and the University of Indonesia ⁽²⁾. It was agreed that a rescue and rehabilitation centre was needed and education programmes were proposed ⁽⁵⁾. Currently, the only viable protected population is found within the Gunung Halimun National Park; if this attractive primate is to survive it is vital that protection both within the park and in other areas is increased ⁽⁶⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn more about a Whitley Award-winning conservation project for this species, click here.

Find out more

For more information on the Javan gibbon:

• The Silvery Gibbon Project:
  www.silvery.org.au
• The Gibbon Conservation Center:
  http://www.gibboncenter.org/

Authentication

Authenticated by Dr David J. Chivers, University of Cambridge.

Glossary

Arboreal

Tree dwelling.

Brachiation

In some primates, a method of locomotion when the animal swings hand over hand from branch to branch.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Monogamous

Having only one mate during a breeding season, or throughout the breeding life of a pair.

Montane

Of mountains, or growing in mountains.

Territory

An area occupied and defended by an animal, a pair of animals or a colony.

References

1. IUCN Red List (April, 2011)
   http://www.redlist.org
2. MacDonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, London.
3. CITES (March, 2003)
   http://www.cites.org
4. The Silvery Gibbon Project (July, 2002)
   http://www.silvery.org.au/technical.html
5. Primate Info Net (March, 2003)
   http://www.primate.wisc.edu/pin/factsheets/hylobates_moloch.html
6. Animal Info (July, 2002)
   http://www.animalinfo.org/species/primate/hylomolo.htm
7. Asquith, N., Martarinza, M. and Sinaga, R.M. (1995) The Javan gibbon (Hylobates moloch): status and conservation recommendations. Tropical Biodiversity, 3: 1 - 14.
8. Asquith, N.M. (1995) Javan gibbon conservation: why habitat protection is crucial. Tropical Biodiversity, 3: 63 - 65.