Nycticebus borneanus

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Nycticebus borneanus
Nycticebus borneanus (Nycticebus coucang borneanus) - Museo Civico di Storia Naturale Giacomo Doria - Genoa, Italy - DSC02519.JPG
CITES Appendix I (CITES) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Suborder: Strepsirrhini
Family: Lorisidae
Genus: Nycticebus
Species:
N. borneanus
Binomial name
Nycticebus borneanus
(Lyon, 1906)

Nycticebus borneanus, the Bornean slow loris, [3] is a strepsirrhine primate and a species of slow loris that is native to central south Borneo in Indonesia. Formerly considered a subspecies or synonym of N. menagensis , it was promoted to full species status in 2013 when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it as a separate species. It is distinguished by its dark, contrasting facial features, as well as the shape and width of the stripes of its facial markings.

As with other slow lorises, this arboreal and nocturnal species primarily eats insects, tree gum, nectar, and fruit and has a toxic bite, a unique feature among primates. Although not yet evaluated by the International Union for Conservation of Nature (IUCN), it is likely to be listed as "Vulnerable" or placed in a higher-risk category when its conservation status is assessed. It is primarily threatened by habitat loss and the illegal wildlife trade.

Taxonomy and phylogeny

N. borneanus is a strepsirrhine primate, and species of slow loris (genus Nycticebus) within the family Lorisidae. Museum specimens of this animal had previously been identified as the Bornean slow loris using the scientific name Nycticebus menagensis – first described by the English naturalist Richard Lydekker in 1893 as Lemur menagensis, [4] – a scientific name now assigned exclusively to the Philippine slow loris. In 1906, Marcus Ward Lyon Jr. first described N. borneanus from western Borneo. [5] By 1953, all of the slow lorises were lumped together into a single species, the Sunda slow loris (Nycticebus coucang). [6] In 1971, that view was updated by distinguishing the pygmy slow loris (N. pygmaeus) as a species, and by further recognizing four subspecies, including N. coucang menagensis. [7] [8] From then until 2005, N. borneanus was considered a synonym of N. menagensis. [9] The latter was elevated to the species level in 2006, when molecular analysis showed it to be genetically distinct from N. coucang. [10]

A 2013 review of museum specimens and photographs attributed to N. menagensis resulted in elevating two of its former subspecies to species: N. bancanus and N. borneanus. [11] Additionally, N. kayan emerged as a new species, which had previously been overlooked. All newly recognized or elevated species showed significant differences in their "face mask"—the coloration patterns on their face. [11]

Physical description

Female, from Nanga Tayap, Ketapang Regency Nyctice bornean 120322-24228 sndai.JPG
Female, from Nanga Tayap, Ketapang Regency

Like other slow lorises, it has a vestigial tail, round head, and short ears. [12] It has a rhinarium (the moist, naked surface around the nostrils of the nose) and a broad, flat face with large eyes. [13] Like N. menagensis, this and all other Bornean species lack a second upper incisor, which distinguishes them from other slow lorises. [14] On its front feet, the second digit is smaller than the rest; the big toe on its hind foot opposes the other toes, which enhances its gripping power. Its second toe on the hind foot has a curved grooming claw that it uses for scratching and grooming, while the other nails are straight. [13] It also possesses a specialized arrangement of lower front teeth, called a toothcomb, which is also used for grooming, as with other lemuriform primates. [15] On the ventral side of its elbow, it has a small swelling called the brachial gland, which secretes a pungent, clear oily toxin that the animal uses defensively by wiping it on its toothcomb. [16]

The facial markings of N. borneanus are dark and contrasting. The dark rings around its eyes are usually rounded on top, though sometimes diffuse-edged, and they never reach below the zygomatic arch. The stripe between the eyes often varies in width, the ears are covered in hair, and the band of hair in front of the ears is wide. The colored patch on the top of the head is usually round, but is sometimes a narrower band. The body length averages 260.1 mm (10.24 in) for the species. [14]

Distribution

N. borneanus is found in central south Borneo, in the Indonesian provinces of West, South, and Central Kalimantan. Its range extends south of the Kapuas River and east to the Barito River. However, N. borneanus is not found in the extreme southwest of the island. It may be sympatric with N. bancanus in the province of West Kalimantan. [17]

Habitat and ecology

Like other slow lorises, N. borneanus is arboreal, nocturnal, [12] and omnivorous, eating primarily insects, tree gum, nectar, and fruit. [18] Likewise, this species has a toxic bite, a unique feature found only in slow lorises among primates. The toxin is produced by licking a brachial gland (a gland by their elbow), and the secretion mixes with its saliva to activate. Their toxic bite is a deterrent to predators, and the toxin is also applied to the fur during grooming as a form of protection for their infants. When threatened, slow lorises may also lick their brachial glands and bite their aggressors, delivering the toxin into the wounds. Slow lorises can be reluctant to release their bite, which is likely to maximize the transfer of toxins. [19]

The face mask may help the species identify potential mates by distinguishing species, and may serve as an anti-predator strategy by making its eyes appear larger than they really are. [20]

Conservation

While this new species has yet to be assessed by the IUCN, N. menagensis was listed as "Vulnerable" as of 2012. [11] Because that species has been divided into four distinct species, each of the new species faces a higher risk of extinction. Accordingly, each of them are expected to be listed as "Vulnerable" at the least, with some of them likely to be assigned to a higher-risk category. [21]

Between 1987 and 2012, one-third of Borneo's forests have been lost, making habitat loss one of the greatest threats to the survival of N. borneanus. The illegal wildlife trade is also a major factor, [11] with loris parts commonly sold in traditional medicine and viral videos on YouTube promoting the exotic pet trade. [21] [22] [23] However, all slow loris species are protected from commercial trade under Appendix I of CITES. [24]

Related Research Articles

<span class="mw-page-title-main">Lorisidae</span> Family of primates

Lorisidae is a family of strepsirrhine primates. The lorisids are all slim arboreal animals and comprise the lorises, pottos and angwantibos. Lorisids live in tropical, central Africa as well as in south and southeast Asia.

<span class="mw-page-title-main">Loris</span> Subfamily of primates

Loris is the common name for the strepsirrhine mammals of the subfamily Lorinae in the family Lorisidae. Loris is one genus in this subfamily and includes the slender lorises, Nycticebus is the genus containing the slow lorises, and Xanthonycticebus is the genus name of the pygmy slow loris.

<span class="mw-page-title-main">Strepsirrhini</span> Suborder of primates

Strepsirrhini or Strepsirhini is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Collectively they are referred to as strepsirrhines. Also belonging to the suborder are the extinct adapiform primates which thrived during the Eocene in Europe, North America, and Asia, but disappeared from most of the Northern Hemisphere as the climate cooled. Adapiforms are sometimes referred to as being "lemur-like", although the diversity of both lemurs and adapiforms does not support this comparison.

<span class="mw-page-title-main">Slow loris</span> Genus of primates from Southeast Asia

Slow lorises are a group of several species of nocturnal strepsirrhine primates that make up the genus Nycticebus. Found in Southeast Asia and bordering areas, they range from Bangladesh and Northeast India in the west to the Sulu Archipelago in the Philippines in the east, and from Yunnan province in China in the north to the island of Java in the south. Although many previous classifications recognized as few as a single all-inclusive species, there are now at least eight that are considered valid: the Sunda slow loris (N. coucang), Bengal slow loris (N. bengalensis), Javan slow loris (N. javanicus), Philippine slow loris (N. menagensis), Bangka slow loris (N. bancanus), Bornean slow loris (N. borneanus), Kayan River slow loris (N. kayan) and Sumatran slow loris. A ninth species, the pygmy slow loris (X. pygmaeus), was recently moved to the new genus Xanthonycticebus. After the pygmy slow loris, the group's closest relatives are the slender lorises of southern India and Sri Lanka. Their next closest relatives are the African lorisids, the pottos, false pottos, and angwantibos. They are less closely related to the remaining lorisoids, and more distantly to the lemurs of Madagascar. Their evolutionary history is uncertain since their fossil record is patchy and molecular clock studies have given inconsistent results.

<span class="mw-page-title-main">Venomous mammal</span> Venom-producing animals of the class Mammalia

Venomous mammals are animals of the class Mammalia that produce venom, which they use to kill or disable prey, to defend themselves from predators or conspecifics or in agonistic encounters. Mammalian venoms form a heterogeneous group with different compositions and modes of action, from four orders of mammals: Eulipotyphla, Monotremata, Primates, and Chiroptera. To explain the rarity of venom delivery in Mammalia, Mark Dufton of the University of Strathclyde has suggested that modern mammalian predators do not need venom because they are able to kill quickly with their teeth or claws, whereas venom, no matter how sophisticated, requires time to disable prey.

<span class="mw-page-title-main">Sunda slow loris</span> Species of primate found in South East Asia

The Sunda slow loris, or greater slow loris, is a strepsirrhine primate and a species of slow loris native to Indonesia, West Malaysia, southern Thailand and Singapore. It measures 27 to 38 cm from head to tail and weighs between 599 and 685 g. Like other slow lorises, it has a wet nose (rhinarium), a round head, small ears hidden in thick fur, a flat face, large eyes and a vestigial tail.

<span class="mw-page-title-main">Pygmy slow loris</span> Species of primate

The pygmy slow loris is a species of slow loris found east of the Mekong River in Vietnam, Laos, eastern Cambodia, and China. It occurs in a variety of forest habitats, including tropical dry forests, semi-evergreen, and evergreen forests. It was originally classified within Nycticebus until it was transferred to the genus Xanthonycticebus in 2022. Two species are recognised, the northern pygmy loris X. intermedius from northern Vietnam, Laos and China and the southern pygmy loris X. pygmaeus from southern Vietnam, Laos and Cambodia. The animal is nocturnal and arboreal, crawling along branches using slow movements in search of prey. Unlike other primates, it does not leap. It lives together in small groups usually with one or two offspring. An adult can grow to around 19 to 23 cm long and has a very short tail. It weighs about 450 g (1.0 lb). Its diet consists of fruits, insects, small fauna, tree sap, and floral nectar. The animal has a toxic bite, which it gets by licking a toxic secretion from glands on the inside of its elbows. The teeth in its lower jaw form a comb-like structure called a toothcomb that is used for scraping resin from tree bark.

<span class="mw-page-title-main">Bengal slow loris</span> Species of primate

The Bengal slow loris or northern slow loris is a strepsirrhine primate and a species of slow loris native to the Indian subcontinent and Indochina. Its geographic range is larger than that of any other slow loris species. Considered a subspecies of the Sunda slow loris (N. coucang) until 2001, phylogenetic analysis suggests that the Bengal slow loris is most closely related to the Sunda slow loris. However, some individuals in both species have mitochondrial DNA sequences that resemble those of the other species, due to introgressive hybridization. It is the largest species of slow loris, measuring 26 to 38 cm from head to tail and weighing between 1 and 2.1 kg. Like other slow lorises, it has a wet nose (rhinarium), a round head, flat face, large eyes, small ears, a vestigial tail, and dense, woolly fur. The toxin it secretes from its brachial gland differs chemically from that of other slow loris species and may be used to communicate information about sex, age, health, and social status.

<span class="mw-page-title-main">Slender loris</span> Genus of primates

The slender lorises (Loris) are a genus of loris native to India and Sri Lanka. The genus comprises two species, the red slender loris found in Sri Lanka and the gray slender loris from Sri Lanka and India. Slender lorises spend most of their life in trees, traveling along the tops of branches with slow and precise movements. They are found in tropical rainforests, scrub forests, semi-deciduous forests, and swamps. The primates have lifespans of approximately 15 years and are nocturnal. Slender lorises generally feed on insects, reptiles, plant shoots, and fruit.

<span class="mw-page-title-main">Gray slender loris</span> Species of primate

The gray slender loris is a species of primate in the family Loridae. It is native to India and Sri Lanka and inhabits subtropical and tropical dry forests and subtropical or tropical moist lowland forests. It is threatened by habitat loss.

<span class="mw-page-title-main">Javan slow loris</span> Species of primate native to Indonesia

The Javan slow loris is a strepsirrhine primate and a species of slow loris native to the western and central portions of the island of Java, in Indonesia. Although originally described as a separate species, it was considered a subspecies of the Sunda slow loris (N. coucang) for many years, until reassessments of its morphology and genetics in the 2000s resulted in its promotion to full species status. It is most closely related to the Sunda slow loris and the Bengal slow loris (N. bengalensis). The species has two forms, based on hair length and, to a lesser extent, coloration.

<span class="mw-page-title-main">Philippine slow loris</span> Species of primate

The Philippine slow loris is a strepsirrhine primate and a species of slow loris that is native to the north and east coastal areas of the island of Borneo, as well as the Sulu Archipelago in the Philippines. The species was first named as the Bornean slow loris in 1892, but lumped into the widespread Sunda slow loris (N. coucang) in 1952. However, it was promoted to full species status – again as the Bornean slow loris – based on molecular analysis in 2006. In 2013, two former subspecies of the Bornean slow loris were elevated to species status, and a new species—N. kayan—was recognized among the Bornean population.

? Nycticebus linglom is a fossil strepsirrhine primate from the Miocene of Thailand. Known only from a single tooth, an upper third molar, it is thought to be related to the living slow lorises, but the material is not sufficient to assign the species to Nycticebus with certainty, and the species name therefore uses open nomenclature. With a width of 1.82 mm, this tooth is very small for a primate. It is triangular in shape, supported by a single root, and shows three main cusps, in addition to various crests. The absence of a fourth cusp, the hypocone, distinguishes it from various other prosimian primates.

<span class="mw-page-title-main">Conservation of slow lorises</span> Conservation management of the nocturnal primates in Asia

Slow lorises are nocturnal strepsirrhine primates in the genus Nycticebus that live in the rainforests of South and Southeast Asia. They are threatened by habitat loss and fragmentation from deforestation, selective logging, and slash-and-burn agriculture, as well as by collection and hunting for the wildlife trade, including the exotic pet trade, and for use in traditional medicine and as bushmeat. Because of these and other threats, all five species of slow loris are listed as either "Vulnerable" or "Endangered" by the International Union for Conservation of Nature (IUCN). Their conservation status was originally listed as "Least Concern" in 2000 because of imprecise population surveys and the frequency in which these primates were found in animal markets. Because of their rapidly declining populations and local extinctions, their status was updated and in 2007 the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) elevated them to Appendix I, which prohibits international commercial trade. Local laws also protect slow lorises from hunting and trade, but enforcement is lacking in most areas.

<i>Nycticebus kayan</i> Species of primate

The Kayan River slow loris is a strepsirrhine primate and a species of slow loris that is native to the northern and central highland region of the island of Borneo. The species was originally thought to be a part of the Bornean slow loris (N. menagensis) population until 2013, when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it. It is distinguished by the high contrast of its black and white facial features, as well as the shape and width of the stripes of its facial markings.

<i>Nycticebus bancanus</i> Species of primate

The Bangka slow loris is a strepsirrhine primate and a species of slow loris that is native to southwestern Borneo and the island of Bangka. Originally considered a subspecies or synonym of the Bornean slow loris (N. menagensis), it was promoted to full species status in 2013 when a study of museum specimens and photographs identified distinct facial markings, which helped to differentiate it as a separate species. It is distinguished by the crimson red fur on its back, light-colored facial features, as well as the shape and width of the stripes of its facial markings.

The Bornean slow loris is a strepsirrhine primate and a species of slow loris that is native to Borneo in Indonesia.

<span class="mw-page-title-main">Primatology and Conservation at Oxford Brookes University</span> Primatalogy and conservation programmes

The Primatology and Conservation programmes at Oxford Brookes University are part of the Department of Social Science, with links to the Department of Health and Life Sciences. It traces its origins to the anthropology courses offered at the then Oxford Polytechnic in the 1970s and developed into a globally recognised centre for primate conservation.

References

  1. ↑ Nekaris, K.A.I.; Miard, P. (2020). "Nycticebus borneanus". IUCN Red List of Threatened Species . 2020. IUCN: e.T163015906A163015915. doi: 10.2305/IUCN.UK.2020-2.RLTS.T163015906A163015915.en .
  2. ↑ "Appendices I, II and III" (PDF). Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). 2010. Archived from the original (PDF) on 2010-12-24. Retrieved 2012-12-14.
  3. ↑ "Nycticebus borneanus". Integrated Taxonomic Information System . Retrieved 28 January 2016.
  4. ↑ Munds, Nekaris & Ford 2013, p. 46.
  5. ↑ Lyon 1906, pp. 535–536.
  6. ↑ Osman Hill 1953, pp. 156–163.
  7. ↑ Groves 1971.
  8. ↑ Groves 2001, p. 99.
  9. ↑ Groves 2005, p. 122.
  10. ↑ Chen et al. 2006, p. 1198.
  11. 1 2 3 4 Munds, Nekaris & Ford 2013, p. 47.
  12. 1 2 Ankel-Simons 2007, p. 82.
  13. 1 2 Smith & Xie 2008, pp. 159–160.
  14. 1 2 Munds, Nekaris & Ford 2013, p. 53.
  15. ↑ Ankel-Simons 2007, p. 246.
  16. ↑ Hagey, Fry & Fitch-Snyder 2007, p. 253.
  17. ↑ Munds, Nekaris & Ford 2013, p. 52–53.
  18. ↑ Nekaris & Bearder 2007, pp. 28–33.
  19. ↑ Alterman 1995, pp. 421–423.
  20. ↑ Munds, Nekaris & Ford 2013, p. 49.
  21. 1 2 Wall, T. (13 December 2012). "Three new species of venomous primate identified by MU researcher". Missouri University News Bureau. Archived from the original on 17 December 2012. Retrieved 19 December 2012.
  22. ↑ Bryner, J. (14 December 2012). "Slow loris species, Nycticebus kayan, discovered in Borneo". The Huffington Post. Archived from the original on 17 December 2012. Retrieved 15 December 2012.
  23. ↑ Walker, M. (13 December 2012). "Primate species: new slow loris found in Borneo". BBC News. Archived from the original on 25 December 2012.
  24. ↑ Nekaris & Munds 2010, p. 390.

Literature cited

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