Bengal slow loris
Bengal slow loris[1] | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Primates |
Suborder: | Strepsirrhini |
Family: | Lorisidae |
Genus: | Nycticebus |
Species: | N. bengalensis
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Binomial name | |
Nycticebus bengalensis (Lacépède, 1800)
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Range of the Bengal slow loris | |
Synonyms[4][5] | |
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The Bengal slow loris (Nycticebus bengalensis) or northern slow loris is a
The Bengal slow loris is
The species is listed as endangered on the
Taxonomy and phylogeny
Nycticebus bengalensis, commonly known as the Bengal slow loris or northern slow loris,[6] is a strepsirrhine primate in the slow loris genus, Nycticebus. Formerly considered a subspecies of the Sunda slow loris (N. coucang), it was recognized as a distinct species in 2001 by taxonomist and primatologist Colin Groves.[1] It is difficult to distinguish from the other species in its genus.[6]
To help clarify species and subspecies boundaries, and to establish whether
Anatomy and physiology
The Bengal slow loris is the largest species of slow loris, weighing 1 to 2.1 kg (2.2 to 4.6 lb),
In addition to being smaller than the Bengal slow loris, the sympatric Sunda slow loris also differs in its coloring: it does not have the pale areas of the head, nape, and shoulders, and its overall color is a tawny- or golden-brown.[10] The pygmy slow loris (N. pygmaeus) is much smaller, with a skull length less than 55 mm (2.2 in).[5] It also lacks the dark dorsal stripe of the Bengal slow loris,[14] has dark brown fur, and longer ears.[15]
The Bengal slow loris has a small swelling on the ventral side of its elbow called the brachial gland, which secretes a pungent, clear oily toxin that the animal uses defensively by wiping it on its
Behavior and ecology
The preferred habitats of the Bengal slow loris range across
The species acts as an important
A nocturnal animal, the Bengal slow loris has excellent night vision, enhanced by a tapetum lucidum—a layer of tissue in the eye that reflects visible light back through the retina. It sleeps during the day curled up in a ball in dense vegetation or in tree holes. Males and females mark their territory with urine.[23] The species is known to live in small family groups.[6] Animals may practice social grooming.[23]
Reproduction
The Bengal slow loris is not a seasonal breeder, unlike the pygmy slow loris.[8] Females in an estrous cycle attract males with a loud whistle. Females reproduce every 12–18 months and have a six-month gestation.[23] Because they are not seasonal breeders, females could become pregnant when their offspring are approximately 6 months old, making possible for females to produce two offspring per year.[8] Females typically give birth to a single offspring, although twins rarely occur.[23] This differs from the sympatric pygmy slow loris, which commonly has twins.[8] The mother carries her young about three months before they become independent, although they may be temporarily left on branches while the mother searches for food.[23] Sexual maturity is reached at approximately 20 months of age.[6] The species is known to live up to 20 years.[6]
Distribution
The species has the largest geographic range of all slow loris species
The Bengal slow loris is
Conservation
Listed as "
The most severe threats facing the species are the
The species is commonly sold as a pet and to zoos throughout Southeast Asia. In Cambodia, it was reported in 2006 as one of the most common mammals found in shops and stalls, found in the hundreds and selling for US$0.85 to US$6.25. In the same year, it was found selling for US$2.50 to US$6.30 at bazaars in China (Mengla County in Yunnan Province) and US$70 in Thailand. The Bengal slow loris is used in traditional medicine in all of these countries, selling for US$15 in Vietnam, and is also eaten in Vietnam.[6] The animal is predominantly used to prepare treatments for women after childbirth, stomach problems, healing wounds and broken bones, and in the treatment of sexually transmitted diseases. Primary users are wealthy to middle-class women in urban areas.[28]
Habitat and population trends
Throughout its geographic range, slow lorises are in serious decline. Their habitat has been seriously degraded, and growing human populations will add increasing pressure. In countries like Bangladesh, only 9% of the original forest cover was still present in 2000. In northeastern Cambodia, forests are being cleared at an increasing rate, with a loss of 6% of the natural forest between 1999 and 2000. Within those same years, Myanmar and Thailand lost 14% and 26% of their natural forest, respectively. In Vietnam, only 30% of the original forest cover remains due to the deforestation caused by the
In India, dense forest canopy has been depleted by as much as 55% in some areas and is rapidly disappearing. As early as 1987, the Indo-China region had reportedly lost 75% of the natural habitat for slow lorises. In 1992, the population size was estimated between 16,000 and 17,000 individuals, based on available habitat; however, recent publications report that few individuals remain due to a reduced geographic range. The Bengal slow loris may be restricted to a few isolated populations and is in serious threat of becoming locally extinct in parts of Assam and Meghalaya. In Arunachal Pradesh, its population is declining and under threat.[6][25]
Since the 1990s, China's forests have declined significantly. In
References
- ^ a b Groves 2005, pp. 122–123.
- ^ . Retrieved 19 November 2021.
- ^ UNEP-WCMC. "CITES species database: Nycticebus bengalensis". UNEP-WCMC Species Database. Retrieved 3 February 2011.[permanent dead link]
- ^ Groves 2005, p. 122.
- ^ a b c Groves 2001, p. 99.
- ^ a b c d e f g h i j k l m n o p q r s Management Authority of Cambodia (3–15 June 2007). Notification to Parties: Consideration of Proposals for Amendment of Appendices I and II (PDF). Netherlands: CITES. p. 31. Archived from the original (PDF) on 28 February 2011. Retrieved 9 January 2011.
- ^ Chen et al. 2006, pp. 1197–1198.
- ^ S2CID 35725257.
- ^ a b Nekaris et al. 2010, p. 157.
- ^ a b Osman Hill 1953, p. 160.
- ^ S2CID 6679294.
- ^ a b Smith et al. 2008, pp. 159–160.
- ^ a b c d e Swapna, N.; Gupta, Atul; Radhakrishna, Sindhu (2008). "Distribution survey of Bengal Slow Loris Nycticebus bengalensis in Tripura, northeastern India" (PDF). Asian Primates Journal. 1 (1): 37–40. Archived from the original (PDF) on 2011-07-27.
- ^ Smith et al. 2008, p. 159.
- ^ Osman Hill 1953, p. 162–163.
- ^ Hagey, Fry & Fitch-Snyder 2007, p. 253.
- ^ Hagey, Fry & Fitch-Snyder 2007, p. 263.
- ^ Hagey, Fry & Fitch-Snyder 2007, p. 269.
- ^ Francis 2008, p. 261.
- ^ S2CID 31261833.
- ^ Nekaris et al. 2010.
- S2CID 23726143.
- ^ a b c d e f Smith et al. 2008, p. 160.
- ^ a b Nandini, Rajamani; Kakati, Kashmira; Ved, Nimesh (2009). "Occurrence records of the Bengal Slow Loris (Nycticebus bengalensis) in northeastern India" (PDF). Asian Primates Journal. 1 (2): 12–18. Archived from the original (PDF) on 2012-03-03.
- ^ ISSN 0974-7907.
- S2CID 45718454. Archived from the originalon 24 July 2011. Retrieved 9 January 2011.
- .
- doi:10.3354/esr00285. Archived(PDF) from the original on 2020-12-02. Retrieved 2020-01-27.
Literature cited
- Francis, Charles A. (2008). A Field Guide to the Mammals of South-East Asia. London: New Holland. ISBN 978-1-84537-735-9.
- Chen, J. -H.; Pan, D.; Groves, C. P.; Wang, Y. -X.; Narushima, E.; Fitch-Snyder, H.; Crow, P.; Thanh, V. N.; Ryder, O.; Zhang, H. -W.; Fu, Y.; Zhang, Y. (2006). "Molecular phylogeny of Nycticebus inferred from mitochondrial genes". International Journal of Primatology. 27 (4): 1187–1200. S2CID 24319996.
- OCLC 62265494.
- ISBN 978-1-56098-872-4.
- Hagey, L.R.; Fry, B.G.; Fitch-Snyder, H. (2007). "Talking defensively, a dual use for the brachial gland exudate of slow and pygmy lorises". In Gursky, S.L.; Nekaris, K.A.I. (eds.). Primate Anti-Predator Strategies. Developments in Primatology: Progress and Prospects. Springer. pp. 253–273. ISBN 978-0-387-34807-0.
- Nekaris, K. A. I.; Starr, C. R.; Collins, R. L.; Wilson, A. (2010). "Comparative Ecology of Exudate Feeding by Lorises (Nycticebus, Loris) and Pottos (Perodicticus, Arctocebus)". In Burrows, A. M.; Nash, L. T (eds.). The Evolution of Exudativory in Primates. New York: Springer. pp. 155–168. ISBN 978-1-4419-6660-5.
- Osman Hill, W.C. (1953). Primates Comparative Anatomy and Taxonomy I—Strepsirhini. Edinburgh Univ Pubs Science & Maths, No 3. Edinburgh University Press. OCLC 500576914.
- Smith, Andrew T.; Xie, Yan; Hoffman, Robert S.; Lunde, Darrin (2008). A Guide to the Mammals of China. Princeton University Press. ISBN 978-0-691-09984-2.