These animals are not known to have a negative effect on humans.
Details on predation of these animals are not available. However, we can speculate that because they use the high canopy of the rainforest, where branches might support the weight of large animals, their predators are probably small or avian.
Adult molochs weigh on average 8 kg. There is no apparent sexual dimorphism (size or color difference) between males and females. Both male and female are a silverly-gray color and possess a dark gray cap. Molochs have long arms and lean bodies, both of which are especially important while they are manuvering through the canopy of the rainforest.
Range mass: 4 to 9 kg.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Other species in this genus are reported to live as long as 44 years in captivity. Hylobates moloch is probably similar.
Average lifespan
Status: captivity: 45 years.
Gibbons live in the tropical rainforests and semi-evergreen rainforests of South and Southeast Asia. Hylobates moloch is found in the tropical rainforest in Java. It is found in the upper canopy of the lowland and hill forests. Gibbons spend most of their lives in trees, and rarely descend to the forest floor.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: rainforest
Molochs, Hylobates moloch, are endemic to the Indonesian island of Java.
Biogeographic Regions: oriental (Native )
Other Geographic Terms: island endemic
Along with other gibbon species, H. moloch is frugivorous, feeding on ripe fruits in the upper canopy of the tropical rainforests. Molochs have also been observed eating leaves and flowers. Being frugivorous poses certain problems because fruit patches are found in small, scattered areas throughout the rainforest. Gibbons have adopted a rapid form of locomotion, brachiation, in which they swing by their long arms from branch to branch. This rapid form of locomotion helps gibbons to travel rapidly and effeciently from one food source to another.
Plant Foods: leaves; fruit; flowers
Primary Diet: herbivore (Frugivore )
The role these primates play in their ecosystem has not been detailed in the literature. However, it is likely that through their frugivory, they play some role in seed dispersal.
Ecosystem Impact: disperses seeds
Hylobates moloch is not an important economic resource for humans. This species is not used for biomedical research, unlike some other primate species. Molochs are sometimes hunted for meat, and illegal poaching does occur for the pet trade.
Positive Impacts: pet trade ; food
This species is endangered. The biggest threat to gibbons is deforestation of the tropical rainforests. Habitats are disappearing at an astonishing rate due to logging and agricultural demands. Without a sufficient range, gibbon species, along with other tropical species, are finding it much harder to exist. In an effort to help save these primates, reserves and parks are created, but there is no conservation program specifically for H. moloch. Other threats to gibbons include hunting for meat, and illegal poaching for the pet trade. These threats, although serious, are secondary to deforestation.
US Federal List: no special status
CITES: appendix i
IUCN Red List of Threatened Species: endangered
Vocal communication is prevalent in all gibbon species. Mated pairs use duets to mark their territory and announce their presence to conspecifics. In addition to vocalizations, gibbons use facial expressions and body postures in communication. Tactile communication is of some importance between mates, as well as between parents and their offspring.
Communication Channels: visual ; tactile ; acoustic
Other Communication Modes: duets
Perception Channels: visual ; tactile ; acoustic ; chemical
Gibbons are typically monogamous.
Mating System: monogamous
The available data on gibbons show no birth seasonality. A mated gibbon pair will produce an average of 5 to 6 offspring over their reproductive lifespan of about 10 to 20 years. Like most primates, H. moloch produces one young per litter, with a gestation length of around seven months. The interbirth period of a reproductive female is about 40 months.
Breeding interval: The interbirth period of a reproductive female is about 40 months.
Breeding season: There is no defined breeding season for H. moloch.
Average number of offspring: 1.
Average gestation period: 7 months.
Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; induced ovulation ; viviparous
Average gestation period: 243 days.
Average number of offspring: 1.
Although no specific information is available, most female gibbons nurse their offspring until the offspring are about two years old. Offspring leave their natal group when they become sexually mature.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); post-independence association with parents; extended period of juvenile learning
The silvery gibbon (Hylobates moloch), also known as the Javan gibbon, is a primate in the gibbon family Hylobatidae. It is endemic to the Indonesian island of Java, where it inhabits undisturbed rainforests up to an altitude of 2,450 m (8,040 ft). It is listed as Endangered on the IUCN Red List since 2008, as the wild population is estimated at comprising less than 2500 mature individuals.[2]
Its coat is bluish-grey in colour, with a dark grey or black cap. Like all gibbons, the silvery gibbon lacks an external tail, has dorsally placed scapulae, and reduced flexibility in its lumbar region. It has long, curved fingers and very long forelimbs relative to its hind limbs. On average, it reaches 8 kg (18 lb) in weight. It is diurnal and arboreal, climbing trees skilfully and brachiating through the forests. Brachiation is possible because of its mobile wrist joints, full rotation of the upper arm, and the ability to lock elbows in suspension. Its diet consists of fruits, leaves, and flowers.
Every three years, on average, the female gives birth to a single young, after a gestation of seven months. The offspring is nursed for about 18 months and lives with the family group until it is fully mature at about eight to ten years old.[3]
The silvery gibbon ranks among the most threatened primates. It is listed as Endangered on the 2009 IUCN Red List,[2] with the population appearing more stable than in a 2004 assessment of the species being Critically Endangered, which suggested there was a 50% chance of the silvery gibbon becoming extinct within the next decade.[4] Habitat destruction on densely populated Java continues to reduce the natural range of the species. Many gibbons are also lost to the illegal pet trade, when adults are hunted so their young can be sold in the markets as pets.[4] There are less than 2,000 silvery gibbons in the wild on eight sites that are considered to be genetically viable for the continuation of the species. There are also a dozen small, non-viable populations. Mount Halimun Salak National Park sustains the largest population of ca. 1,000 gibbons.[4] Other large populations of several hundred are found in the Gunung Ciremai National Park and Gunung Gede Pangrango National Park.[5] In the latter there is a Javan Gibbon Centre that rehabilitates ex-captive gibbons.[6]
Several zoos operate silvery gibbon breeding programs. Despite these efforts, the future survival of this species is in question.
Like all gibbon species, the silvery gibbon lives in pairs and stakes out territory that the pair strongly defends; it has relatively small territories of about 42 acres. Females sing to declare their territory several times a day, and if strangers are spotted, the male screams loudly in an attempt to scare them away. The majority of the solo song bouts or scream bouts are produced by the females.[7] The female vocal bouts occur after 0500 hr, with the vocal bout activity peaking around 0600 hr. In contrast, the male vocal bouts primarily occur before 0500 hr.[7] The males are usually very aggressive to others.
Some authors recognize two subspecies of Hylobates moloch:[8]
The silvery gibbon (Hylobates moloch), also known as the Javan gibbon, is a primate in the gibbon family Hylobatidae. It is endemic to the Indonesian island of Java, where it inhabits undisturbed rainforests up to an altitude of 2,450 m (8,040 ft). It is listed as Endangered on the IUCN Red List since 2008, as the wild population is estimated at comprising less than 2500 mature individuals.
Its coat is bluish-grey in colour, with a dark grey or black cap. Like all gibbons, the silvery gibbon lacks an external tail, has dorsally placed scapulae, and reduced flexibility in its lumbar region. It has long, curved fingers and very long forelimbs relative to its hind limbs. On average, it reaches 8 kg (18 lb) in weight. It is diurnal and arboreal, climbing trees skilfully and brachiating through the forests. Brachiation is possible because of its mobile wrist joints, full rotation of the upper arm, and the ability to lock elbows in suspension. Its diet consists of fruits, leaves, and flowers.
Every three years, on average, the female gives birth to a single young, after a gestation of seven months. The offspring is nursed for about 18 months and lives with the family group until it is fully mature at about eight to ten years old.
