Bornean white-bearded gibbon

Bornean white-bearded gibbon
	Bornean white-bearded gibbon, (Hylobates albibarbis) in Tanjung Puting National Park
Conservation status
	; Endangered (IUCN 3.1)
	CITES Appendix I (CITES)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Suborder:	Haplorhini
Infraorder:	Simiiformes
Family:	Hylobatidae
Genus:	Hylobates
Species:	H. albibarbis
Binomial name
	Hylobates albibarbis; Lyon, 1911
	Range of Bornean white-bearded gibbon (green)

The Bornean white-bearded gibbon (Hylobates albibarbis), also known as the Bornean agile gibbon or southern gibbon, is a species of gibbon endemic to southern Borneo. It is an endangered species, due to the ongoing logging of tropical forests between the Kapuas and Barito rivers.^[2] Additional issues of concern to the endangerment of white-bearded gibbons also threaten other arboreal primates.^[3]^[4]

The white-bearded gibbon is very similar to other gibbons in their behaviour and their frugivorous diet. The Bornean white-bearded gibbon was formerly considered a subspecies of the agile gibbon but based on recent DNA research, some now classify it as a separate species.^[1]^[4]^[5]

Description and life history

The Bornean white-bearded gibbon is commonly seen with grey or dark brown fur, a black face, and white beard. Similar to other gibbons, these gibbons are a smaller ape that is tailless. They tend to live in small family groups consisting of a male, female, and their offspring. They express pair-bonding relationships and they do not make nests. Their mode of transportation is called brachiation, where they swing from branches to get around. They have been documented to swing up to 15 meters (49.2 feet) in a single leap and as fast as 55 kilometers (34 miles) per hour. Apart from other primates, all gibbons walk bipedally; holding their long arms over their heads.^[6]^[7]

The average life span for a white-bearded gibbon is 25 years, and it grows to anywhere from 17 to 25 inches (43 to 64 cm). Male white-bearded gibbons weigh about 6.1 to 6.9 kg (13.5 to 15.2 pounds), and females weigh 5.5 to 6.4 kg (12 to 14 pounds). Female white-bearded gibbons tend to reach sexual maturity in about 48 months.^[8]^[9]

Diet

The Bornean white-bearded gibbons' diet in the tropical forest tends to be frugivorous, where they depend on the abundance of fruit trees and figs; making their diet 65% fruit and 23% figs, respectively. They will occasionally supplement their diet with leaves and insects.^[10]^[11]

Threats

Logging and mining have created a threatening environment in Borneo for gibbons and all arboreal creatures. Since gibbons rely on dense and tall forest areas for safety and for travelling, this is a leading problem for the survival of white-bearded gibbons. Additional threats for the white-bearded gibbon include forest fires due to El Niño events^[2] and climate change.^[4]

References

^ ^a ^b ^c Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press. ISBN 0-801-88221-4. OCLC 62265494.
^ ^a ^b ^c Marshall, A.J.; Nijman, V.; Cheyne, S. (2020). "Hylobates albibarbis". IUCN Red List of Threatened Species. 2020: e.T39879A17967053. doi:10.2305/IUCN.UK.2020-2.RLTS.T39879A17967053.en. Retrieved 20 November 2021.
^ Baker, Nick (2019). "Bornean Gibbon - Hylobates muelleri". www.ecologyasia.com. Ecology Asia. Archived from the original on 16 November 2019.
^ ^a ^b ^c Cheyne, S. M. (2010). "Behavioural ecology of gibbons (Hylobates albibarbis) in a degraded peat-swamp forest". In Gursky, S.; Supriatna, J. (eds.). Indonesian Primates. Developments in Primatology: Progress and Prospects. New York: Springer. pp. 121–156. doi:10.1007/978-1-4419-1560-3_8. ISBN 978-1-4419-1560-3.
^ Hirai, H.; Hayano, A.; Tanaka, H.; Mootnick, A. R.; Wijayanto, H.; Perwitasari-Farajallah, D. (2009). "Genetic differentiation of agile gibbons between Sumatra and Kalimantan in Indonesia". The Gibbons. pp. 37–49. doi:10.1007/978-0-387-88604-6_3. ISBN 978-0-387-88603-9.. p. 37.
^ "Bornean Gibbon - Hylobates muelleri". www.ecologyasia.com. Archived from the original on 2014-07-03. Retrieved 2018-10-21.
^ "Bornean white-bearded gibbon". Project Noah. Retrieved 2018-10-21.
^ Cheyne, Susan M. (2010). "Behavioural Ecology of Gibbons (Hylobates albibarbis) in a Degraded Peat-Swamp Forest". Behavioural Ecology of Gibbon (Hylobates albibarbis) in a Degraded Peat-Swamp Forest. pp. 121–156. doi:10.1007/978-1-4419-1560-3_8. ISBN 978-1-4419-1559-7.
^ "Gibbons | National Geographic". 2010-11-08. Archived from the original on February 4, 2017. Retrieved 2018-10-17.
^ Santosa, Yanto (September 2012). "Cohabitation Study of the Leaf Monkey and Bornean White-Bearded Gibbons in Gunung Palung National Park, West Kalimantan". HAYATI Journal of Biosciences. 19 (3): 115–123. doi:10.4308/hjb.19.3.115.
^ "Gibbons | National Geographic". 2010-11-08. Archived from the original on February 4, 2017. Retrieved 2018-10-17.