Nycticebus bengalensis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Lorisidae

Scientific Name: Nycticebus bengalensis (Lacépède, 1800)
Common Name(s):
English Bengal Slow Loris, Ashy Slow Loris, Bengal Loris, Northern Slow Loris
Nycticebus cinereus Milne-Edwards, 1867
Nycticebus incanus Thomas, 1921
Nycticebus tenasserimensis Elliot, 1913
Taxonomic Notes: This taxon was formerly considered a subspecies of Nycticebus coucang, with which there is a small hybridization zone in peninsular Thailand. No subspecies are recognized. Considerable variation exists in body size and coat colour in this taxon.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2acd+3cd+4acd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Streicher, U., Singh, M., Timmins, R.J. & Brockelman, W.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
Listed as Vulnerable as, due to loss of habitat and severe pressures from hunting, there is more than 30% reduction in population over three generations (approximately 21-24 years). The species is predicted to decline by more than 30% in the next three generations over its entire range due to continuing hunting pressures and loss of habitat.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species occurs in Bangladesh, Cambodia, China (southern Yunnan and possibly southern Guangxi), north-eastern India (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura), Lao PDR, Myanmar (including the Mergui Archipelago), Thailand, and Viet Nam (except the south). It may possibly occur as well in northern Peninsular Malaysia.
Countries occurrence:
Bangladesh; Cambodia; China; India; Lao People's Democratic Republic; Myanmar; Thailand; Viet Nam
Additional data:
Upper elevation limit (metres):2400
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:In Lao PDR, the population seems to be fairly undisturbed and occurs in large forest tracts (R. Timmins pers. comm.). Duckworth (1994) and Ratajszczak (1998) both reported the species as being very rare in Lao PDR, with the former reporting abundance indices of about 0.30-0.65/km, and the latter detecting only three after a several week survey. It is recorded in two areas in Bangladesh: Chittagong and Sylhet (Molur et al. 2003). In India, the encounter rates vary from 0.1 to 0.77/km (Radhakrishna et al. 2006). In Viet Nam, the populations are severely reduced and have disappeared from many forests (Fitch-Snyder and Thanh 2002; V. Thanh pers. comm.). In Cambodia it is widespread, though a long-term survey by Starr has also failed to detect this species in most forests. It is also widespread in Thailand (W. Brockelman pers. comm.), though an on-going study by Pliwsungnoen has found that they are absent from many forests, and are at very low densities when they are present (Pliwsungnoen pers. comm.).
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This is an arboreal, nocturnal species that inhabits tropical evergreen rainforest, semi-evergreen forest, and moist deciduous forest. In Viet Nam it is found only in secondary forests, and on the edge of primary forests; they are also known to come close to agricultural fields and plantations (V. Thanh pers. comm.). It ranges from sea level (U. Streicher pers. comm.) up to 2,400 m (Choudhury 2001). It feeds on fruits and gums, but very few insects as compared to slender or pygmy lorises (U. Streicher pers. comm.).

This animal's life span is about 15 years, and generation time is 7-8 years. Females give birth to one offspring per litter once every two years in semi-wild conditions (Rowe 1996). In captivity, this rate may be slightly higher (U. Streicher pers. comm.).

Threats [top]

Major Threat(s): The major threats that this species' habitat faces include farming, timber removal, human settlement, road building, dams, power lines, fragmentations, soil loss and erosion, and deliberately set fires. They are hunted and traded for food, traditional "medicine", sport, and as pets (Molur et al. 2003; Nekaris and Nijman 2007; V. Thanh and U. Streicher pers. comm.). Road kills represent another threat to this species.

Conservation Actions [top]

Conservation Actions: This species is listed in Bangladesh as Schedule III in the Bangladesh Wildlife (Preservation) (Amendment) Act, 1974. In India, it is listed in Schedule I, part I, under the Indian Wildlife Protection Act, 1972 amended up to 2002. This species is protected in Thailand under the Wildlife Protection of 1992; in China it is Class I, and is given the highest protection in Viet Nam under the Wildlife Protection Law (List IB, Decree 32, 2006) on a par with tigers, elephants and bears. In Cambodia, it is protected under law 359 of the Ministry of Forestry and Fisheries, 1994.

This species is found in a large number of protected areas throughout its range, but possibly at low numbers. Actual surveys rather than anecdotal reports are necessary to determine the true abundance of this species in the wild (Nekaris et al. 2008). The species has been recently transfer from Appendix II to Appendix I of CITES (Nekaris and Nijman 2007).

Classifications [top]

1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland
suitability:Suitable  major importance:Yes
1. Forest -> 1.9. Forest - Subtropical/Tropical Moist Montane
suitability:Suitable  major importance:Yes
1. Land/water protection -> 1.1. Site/area protection
2. Land/water management -> 2.1. Site/area management
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management
3. Species management -> 3.1. Species management -> 3.1.2. Trade management
4. Education & awareness -> 4.3. Awareness & communications
5. Law & policy -> 5.4. Compliance and enforcement -> 5.4.2. National level

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education
  Included in international legislation:Yes
  Subject to any international management/trade controls:Yes
1. Residential & commercial development -> 1.1. Housing & urban areas
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.2. Small-holder farming
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

4. Transportation & service corridors -> 4.1. Roads & railroads
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation
  • 2. Species Stresses -> 2.1. Species mortality

4. Transportation & service corridors -> 4.2. Utility & service lines
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

5. Biological resource use -> 5.1. Hunting & trapping terrestrial animals -> 5.1.1. Intentional use (species is the target)
♦ timing:Ongoing    
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

5. Biological resource use -> 5.3. Logging & wood harvesting -> 5.3.5. Motivation Unknown/Unrecorded
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.3. Trend Unknown/Unrecorded
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

7. Natural system modifications -> 7.2. Dams & water management/use -> 7.2.11. Dams (size unknown)
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.5. Threats
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓   National : ✓ 

♦  Medicine - human & veterinary
 Local : ✓   National : ✓ 

♦  Pets/display animals, horticulture
 Local : ✓   National : ✓ 

♦  Sport hunting/specimen collecting
 Local : ✓   National : ✓ 

Bibliography [top]

Choudhury, A. 1992. The slow loris (Nycticebus coucang) in north-east India. Primate Report 34: 77-83.

Choudhury, A. 2001. Primates in Northeast India: An overview of their distribution and conservation. ENVIS Bulletin: Wildlife and Protected Areas 1(1): 92-101.

Duckworth, J. W. 1994. Field sighting of the Pygmy Loris (Nycticebus pygmaeus) in Laos. Folia Primatologica 63(2): 99-101.

Fitch-Snyder, H. and Thanh, V. N. 2002. A preliminary survey of lorises (Nycticebus spp.) in northern Vietnam. Asian Primates 8(1-2): 1-3.

Groves C.P. 2001. Primate Taxonomy. Smithsonian Institution Press, Washington, DC, USA.

MacKinnon, J. 2008. Order Primates. In: A. T. Smith and Y. Xie (eds), The Mammals of China, pp. 158. Princeton University Press.

Molur, S., Brandon-Jones, D., Dittus, W., Eudey, A., Kumar, A., Singh, M., Feeroz, M. M., Chalise, M., Priya, P. and Walker, S. 2003. Status of South Asian Primates: Conservation Assessment and Managment Plan Report. Workshop Report, 2003. Zoo Outreach Organization/CBSG-South Asia, Coimbatore, India.

Nekaris, K.A.I. and Nijman, V. 2007. CITES proposal highlights rarity of asian nocturnal primates (Lorisidae: Nycticebus). Folia Primatologica 78: 211-214.

Nekaris, K.A.I., Blackham, G.V. and Nijman, V. 2008. Conservation implications of low encounter rates of five nocturnal primate species (Nycticebus spp.) in Asia. Biodversity and Conservation 17(4): 733-747.

Radhakrishna, S., Goswami, A. B. and Sinha, A. 2006. Distribution and conservation of Nycticebus bengalensis in northeastern India. International Journal of Primatology 27(4): 971-982.

Ratajszczak, R. 1998. Taxonomy, distribution and status of the lesser slow loris Nycticebus pygmaeus and their implications for captive management. Folia Primatologica 69: 171-174.

Rowe, N. 1996. The Pictorial Guide to Living Primates. Pogonias Press, East Hampton, NY. USA.

Citation: Streicher, U., Singh, M., Timmins, R.J. & Brockelman, W. 2008. Nycticebus bengalensis. In: . The IUCN Red List of Threatened Species 2008: e.T39758A10263081. . Downloaded on 16 August 2018.
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