Mentawai langur
{{Short description|Species of Old World monkey}}
{{Speciesbox
| name = Mentawai langur{{MSW3 Groves | pages = 172|id=12100664}}
| image_caption = Presbytis potenziani
| status = CR
| status_system = IUCN3.1
| status2 = CITES_A1
| status2_system = CITES
| status2_ref = {{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}
| image =
| genus = Presbytis
| species = potenziani
| authority = (Bonaparte, 1856)
| synonyms =
| range_map = Mentawai Langur area.png
| range_map_caption = Mentawai langur range
}}
The Mentawai langur (Presbytis potenziani) is a species of primate in the family Cercopithecidae. It is endemic to the Mentawai Islands in Indonesia. Its natural habitat is subtropical or tropical dry forests. The Siberut langur (P. siberu) was formerly considered a subspecies of the Mentawai langur.{{cite web|title=Presbytis siberu|url=https://mammaldiversity.org/species-account.php?genus=presbytis&species=siberu|publisher=American Society of Mammalogists|access-date=2020-04-08}}{{cite journal|title=Mitochondrial phylogeny of leaf monkeys (genus Presbytis, Eschscholtz, 1821) with implications for taxonomy and conservation|author=Meyer, Dirk|author2=Rinaldi, Ir. Dones|author3=Ramlee, Hatta|author4=Perwitasari-Farajallah, Dyah|author5=Hodges, Keith|author6=Roos, Christian|journal=Molecular Phylogenetics and Evolution|doi=10.1016/j.ympev.2011.02.015|volume=59|issue=2|year=2011|pages=311–319|pmid=21333742|bibcode=2011MolPE..59..311M |access-date=2020-04-08|url=https://www.sciencedirect.com/science/article/abs/pii/S1055790311000662}}
Description
Mentawai langur infants are born with a white pelage. After two to three weeks, the pelage begins to darken and the face becomes darkly pigmented. This change of coloration begins in the dorsal midline and head and ends laterally. After three months, the belly and chest are dark reddish-brown, throat, cheeks, forehead and tip of tail are white and the rest of the body is jet black. Males are differentiated from females by having a white circumgenital patch of fur.{{Cite journal |last=Tilson |first=R. L. |date=December 1976 |title=Infant Coloration and Taxonomic Affinity of the Mentawai Islands Leaf Monkey, Presbytis potenziani |url=https://academic.oup.com/jmammal/article-lookup/doi/10.2307/1379453 |journal=Journal of Mammalogy |language=en |volume=57 |issue=4 |pages=766–769 |doi=10.2307/1379453 |jstor=1379453 |issn=1545-1542}} Mentawai langurs have a slender body with hind limbs longer than their forelimbs.{{Cite journal |last1=Hadi |first1=Susilo |last2=Ziegler |first2=Thomas |last3=Waltert |first3=Matthias |last4=Syamsuri |first4=Fauzan |last5=Mühlenberg |first5=Michael |last6=Hodges |first6=J. Keith |date=2012-02-01 |title=Habitat Use and Trophic Niche Overlap of Two Sympatric Colobines, Presbytis potenziani and Simias concolor, on Siberut Island, Indonesia |url=https://doi.org/10.1007/s10764-011-9567-y |journal=International Journal of Primatology |language=en |volume=33 |issue=1 |pages=218–232 |doi=10.1007/s10764-011-9567-y |s2cid=11087889 |issn=1573-8604}}
Distribution and habitat
Mentawai langurs are endemic to the islands of Sipora, North Pagai, and South Pagai.{{Cite journal |last=Whittaker |first=Danielle J. |date=May 2006 |title=A Conservation Action Plan for the Mentawai Primates |url=https://bioone.org/journals/primate-conservation/volume-2006/issue-20/0898-6207.20.1.95/A-Conservation-Action-Plan-for-the-Mentawai-Primates/10.1896/0898-6207.20.1.95.full |journal=Primate Conservation |volume=2006 |issue=20 |pages=95–105 |doi=10.1896/0898-6207.20.1.95 |s2cid=85765480 |issn=0898-6207}}{{Cite journal |last=Watanabe |first=Kunio |date=April 1981 |title=Variations in group composition and population density of the two sympatric Mentawaian leaf-monkeys |url=https://doi.org/10.1007/BF02382606 |journal=Primates |language=en |volume=22 |issue=2 |pages=145–160 |doi=10.1007/BF02382606 |s2cid=25252841 |issn=1610-7365}}{{Cite journal |last1=Waltert |first1=Matthias |last2=Abegg |first2=Christophe |last3=Ziegler |first3=Thomas |last4=Hadi |first4=Susilo |last5=Priata |first5=Dodi |last6=Hodges |first6=Keith |date=July 2008 |title=Abundance and community structure of Mentawai primates in the Peleonan forest, north Siberut, Indonesia |journal=Oryx |language=en |volume=42 |issue=3 |pages=375–379 |doi=10.1017/S0030605308000793 |s2cid=208530127 |issn=1365-3008|doi-access=free }} They inhabit primary and secondary forests dominated by dipterocarps.{{Cite journal |last=Hadi |first=Susilo |date=2011-10-31 |title=Feeding Ecology of Mentawai langur (Presbytis potenziani) in Siberut, Mentawai Islands |url=http://www.sunankalijaga.org/prosiding/index.php/icbb/article/view/167 |journal=Proceeding ICBB (The International Conference on Bioscience and Biotechnology) |language=en |volume=1 |issue=1 |pages=B39–B43 |issn=2088-9771}} The trees used by Presbytis potenziani as sleeping areas are typically {{convert|35|m}} in height. The langurs sleep in the mid-upper levels of these trees above {{convert|20|m}}, where the canopy density is thickest, with the most common sites being in coconut groves.
Behavior and diet
On average, groups of Mentawai langurs travel {{convert|540|m}} each day. Heavy rainfall affects movement patterns light to moderate rainfall does not. The langurs move by quadrupedal running and climbing; they also leap in the mid and upper portions of the canopy and drop when nearer to the ground. Home ranges vary from {{convert|11|to|40|ha}}. The groups are not migrants.{{clarify|date=April 2022}} Their social organisation is variable: unimale-unifemale, unimale-multifemale, multimale-multifemale.
Mentawai langurs spend more than 80% of their time resting and foraging and only a small portion traveling and conducting social behavior. Such extensive periods of resting and foraging are required for colobines that consume seeds, unripe fruits and leaves to support their digestion. Adult males typically move away from the group in the early morning and give long calls.
The langurs feed in the upper portion of the canopy. In some areas, their diet consists of 55% leaves, 32% fruit and seed and 13% other source of food such as flowers, bark, sap, and fungi. but groups that forage in secondary forests have a diet of 70% fruits and seeds and up to 35% "climber" type vegetation.{{clarify|reason=exceeds 100%|date=April 2022}} The niche breadth of Presbytis potenziani is 0.22, based on Levin's index.
Conservation
The Mentawai langur is currently listed as critically endangered on the IUCN Red List. Over the 36 years prior to 2021, the population is estimated to have declined by 80%. The main threats to the monkeys are humans hunting for food and destruction of the habitat for agriculture. 25% of the hunting on Mentawai langur is by natives of central-south Siberut. Recommendations to conserve the species include development of a biosphere reserve on Siberut Island, creation of a primate reserve on South Pagai Island and offshore islands, a survey of primates on Sipora Island, a captive breeding program to recover the endemic subspecies of Mentawai primates on the southern islands, and beginning a campaign in education and law enforcement to prevent hunting of Mentawai langurs.
References
{{Reflist}}
{{Taxonbar|from=Q631717}}
Category:Endemic fauna of Indonesia
Category:Mentawai Islands Regency
Category:Primates of Indonesia
Category:Endangered fauna of Asia
Category:Mammals described in 1856
Category:Taxonomy articles created by Polbot