Overview

Distribution

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).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Geographic Range

Gray gibbons, Hylobates muelleri, are found in throughout Borneo excluding the southwest region.

Biogeographic Regions: oriental (Native )

Other Geographic Terms: island endemic

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Morphology

Physical Description

Coloration of H. muelleri varies from gray to brown. The top of the head and the chest are darker than the rest of the body. Total body length ranges from 440 to 635 mm. Gray gibbons weigh between 4 and 8 kg. They have buttock pads, long canine teeth, and no tail. The basal part of the thumb extends from the wrist rather than the palm of the hand, allowing an extended range of movement.

Sexual dimorphism is not pronounced in H. muelleri. Males and females are similar in morphology.

Range mass: 4 to 8 kg.

Range length: 440 to 635 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Habitat and Ecology

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).

Systems
  • Terrestrial
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Gray gibbons live in tropical evergreen and semi-evergreen rain forests.

Habitat Regions: tropical ; terrestrial

Terrestrial Biomes: forest ; rainforest

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Trophic Strategy

Food Habits

The majority of the diet consists of ripe, sugar-rich, fruit and figs. A smaller portion of the diet consists of leaves.

Plant Foods: leaves; fruit

Primary Diet: herbivore (Frugivore )

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Associations

Ecosystem Roles

As frugivores, these animals may play some role in seed dispersal.

Ecosystem Impact: disperses seeds

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Predation

Predation on these animals has not been reported. Avian predators and arboreal snakes are likely to be their most significant predators.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life History and Behavior

Behavior

Communication and Perception

The call of gray gibbons has been studied in detail. Adult males sing long songs before sunrise. Females sing with males after sunrise and before 10:00 AM. Their duets average 15 minutes and occur on a daily basis.

Lone males sing longer songs than paired males, possibly to attract mates. Unpaired females rarely sing.

Grooming and social play are two forms of tactile communication used in this species. Mating is another.

Like other primates, these gibbons likely use gestures, facial expressions, and body postures to communicate.

Communication Channels: visual ; tactile ; acoustic

Other Communication Modes: duets

Perception Channels: visual ; acoustic

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Life Expectancy

Lifespan/Longevity

Although data are lacking for H. muelleri, other members of the genus Hylobates are known to have lived as long as 44 years in captivity, and 25 years in the wild. It is likely that this species is similar.

Range lifespan

Status: captivity:
57 (high) years.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Lifespan, longevity, and ageing

Maximum longevity: 57 years (captivity) Observations: A wild born male was still alive in captivity when about 57 years of age (Richard Weigl 2005).
Creative Commons Attribution 3.0 (CC BY 3.0)

© Joao Pedro de Magalhaes

Source: AnAge

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Reproduction

Gray gibbons are monogamous. The mated pair and their offspring occupy a defended home range.

Mating System: monogamous

The age of sexual maturation is 8 to 9 years.

Females have an estrous cycle of about 28 days. There are no visible sexual swellings, although the genitalia undergo color and turgidity changes that are thought to be associated with ovulation.

From the limited amount of data available, there appears to be no birth seasonality or birth peak in gray gibbons. The gestation period is 7 months. Usually a single young is born.

There is a limited amount of data on the mating of this species. Males initiate mating more frequently than females. If the female is willing to mate, she bends forward in acceptance. If the female is unwilling, she ignores the male or leaves the area.

Most gibbons produce offspring every 2 to 3 years. Nursing may last as long as two years. Because young typically stay with their parents until they reach maturity, it is difficult to say from what age they might be independent. It is reasonable to assume that H. muelleri is similar to other members of the genus with respect to these features.

Breeding interval: These animals likely produce a single offspring every 2 to 3 years.

Breeding season: These animals breed throughout the year.

Average number of offspring: 1.

Average gestation period: 7 months.

Range weaning age: 24 (high) months.

Range time to independence: 9 (high) years.

Range age at sexual or reproductive maturity (female): 8 to 9 years.

Range age at sexual or reproductive maturity (male): 8 to 9 years.

Key Reproductive Features: iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization ; viviparous

Average number of offspring: 1.

Although no specific information is available for gray gibbons, most gibbon females nurse and care for their young for about two years. Because young typically stay with their parents, older siblings may help in care of younger siblings. Males are also usually active in defending and grooming young.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Female, Protecting: Male, Female); pre-independence (Provisioning: Female, Protecting: Male, Female); extended period of juvenile learning

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
EN
Endangered

Red List Criteria
A2cd

Version
3.1

Year Assessed
2008

Assessor/s
Geissmann, T. & Nijman, V.

Reviewer/s
Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)

Contributor/s

Justification
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.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

IUCN classifies H. muelleri as a species at lower risk of extinction. CITES places gray gibbons in their Appendix I category, which means the species is threatened with extinction. Gray gibbons are on the threatened species list due to logging practices on Borneo. Vast amounts of forest have been reduced to nothing. The future of this animal depends on the maintenance of its natural habitat, the forests of Borneo.

US Federal List: no special status

CITES: appendix i

IUCN Red List of Threatened Species: endangered

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population

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.

Population Trend
Decreasing
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

Major Threats
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.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Conservation Actions

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.).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Economic Importance for Humans: Negative

Gray gibbons may compete with humans for certain food sources, such as fruits.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Economic Importance for Humans: Positive

Hylobates muelleri is important in research due to its genetic and physiological similarity to humans.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© The Regents of the University of Michigan and its licensors

Source: Animal Diversity Web

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Müller's Bornean gibbon

Müller's Bornean gibbon (Hylobates muelleri), also known as the grey gibbon, is a primate in the gibbon family, Hylobatidae.

Unlike other gibbon species, Müller's Bornean gibbon does not show sexual dimorphism in its fur coloration. Its fur is grey- or brown-colored with a ring of bright fur around its face. On the head, it often has a darkly colored cap. Weighing between 4-8kg, it ranks among the smaller of the gibbons.[3]

Captive

Müller's Bornean gibbon is endemic to the island of Borneo, inhabiting the northern and eastern part of the island. In the southwest of the island lives the Bornean white-bearded gibbon; their territories hardly overlap. Grey gibbons are diurnal rain forest dwellers, characterized by the long arms that all gibbons have, with which they brachiate through the trees. They live together in monogamous pairs, and defend their family territory against intruders with long, loud singing. Their diet consists primarily of fruits. Little is known about the reproductive patterns of this species, but it is thought to be similar to that of other gibbon species.[3]

Müller's Bornean gibbon occurs in a number of protected areas, including Betung Kerihun National Park, Bukit Baka Bukit Raya National Park, Kayan Mentarang National Park, Kutai National Park, Sungai Wain Protection Forest and Tanjung Puting National Park in Indonesia and Pulong Tau National Park[4] the Lanjak Entimau Wildlife Sanctuary and Semengok Forest Reserve in Malaysia.[2]

Subspecies[edit]

There are three subspecies of this gibbon:[1][5]

References[edit]

  1. ^ a b Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M, eds. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. p. 180. OCLC 62265494. ISBN 0-801-88221-4. 
  2. ^ a b Geissmann, T. & Nijman, V. (2008). Hylobates muelleri. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 4 January 2009.
  3. ^ a b Bruening, S. Shefferly, N., ed. "Hylobates muelleri: Information". Animal Diversity Web. Retrieved 2013-04-12. 
  4. ^ Malaysian Nature Society 1998 Expedition to the proposed Pulong Tau National Park, Sarawak, Malaysia. Malaysian Nature Society, Miri Branch, Miri, Sarawak.
  5. ^ Geissmann, Thomas. "Gibbon Systematics and Species Identification". Retrieved 2006-04-13. 
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!