Loris lydekkerianus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Loris lydekkerianus
Species Authority: Cabrera, 1908
Infra-specific Taxa Assessed:
Common Name(s):
English Gray Slender Loris, Grey Slender Loris, Highland Slender Loris
Loris tardigradus subspecies grandis Hill & Phillips, 1932
Taxonomic Notes: This taxon was formerly considered a subspecies of Loris tardigradus. Although Groves could not distinguish L. l. grandis from L. l. nordicus, the current classification is provisionally maintained pending further taxonomic research, particularly in regard to the montane and submontane forms.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Nekaris, A., Singh, M. & Kumar Chhangani, A.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
Listed as Least Concern in view of its wide distribution, tolerance of a broad range of habitats, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category. If threats arising from habitat loss and hunting increase, this species will need to be reassessed, and could qualify for listing as Near Threatened.
2004 Near Threatened

Geographic Range [top]

Range Description:The species occurs in southern and eastern India (Andhra Pradesh, Karnataka, Kerala and Tamil Nadu) and Sri Lanka.

L. l. lydekkerianus
This subspecies occurs in southern and eastern India (Andhra Pradesh, Karnataka and Tamil Nadu), in the dry shrub jungles of the Eastern Ghats (Schulze and Meier 1995; Nekaris and Jayewardene, 2003; Singh et al. 2000). Singh et al. (1999) recorded this taxon most often in areas up to 1,000 m.

L. l. nordicus
This subspecies occurs in north-central Sri Lanka, in dry-zone areas (A. Nekaris pers. comm.). Recent reports include Mannar, Wilpattu, Anuradhapura, Sigiriya, Polonnaruwa, Mihintale, Ritigale, Minneriya-Giritale, Trincomalee, and Madura Oya. It is uncertain if the range extends to the southeast of the island as no undisputed sighting has yet been made of this subspecies there (Nekaris and de Silva in press).

L. l. grandis
This subspecies is found in the Central Province of Sri Lanka, at an average altitude of 900 m (Schulze and Meier 1995a). Although it has thus far been found only in the East Matale Hills, it is probable that it also occurs throughout the lower foothills of the mountains of central Sri Lanka. The highest altitude from which it has been obtained is 1,036 m. Lorises which may conform to this subspecies have recently been seen at Udawatakele and in the Knuckles Range (Nekaris and de Silva in press).

L. l. malabaricus
This subspecies occurs in India along the west coast and in the wet forests of the Western Ghats in Karnataka, Kerala and Tamil Nadu. It has not been reported from rainforests south of Palghat gap (A. Kumar and M. Singh pers. comm.). It is found from the coast up to 1,200 m in Karnataka, and lower elevations in Kerala.
India; Sri Lanka
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: Loris lydekkerianus nordicuss is known to occur in at least seven distinct populations (Nekaris and Jayewardene 2003). Nekaris and Jayewardene (2004b) carried out a survey of slender lorises in Sri Lanka. Population densities of animal were estimated using the animal encounter rate, or ‘sightings’ per km. Loris lydekkerianus grandis had a density of 0.11 to 3.3 animals/km, with an overall density of 0.42 animals/km, while Loris lydekkerianus nordicus were recorded at a density of 0.33 to 3.5 animals/km, with an overall density of 3.65 animals/km. In some localities of the Eastern Ghats, Karnataka and Andhra Pradesh, the population densities of Loris lydekkerianus lydekkerianus are rather high, although not as high as in Dindigul region (Singh et al. 2000; M. Singh pers. comm.). The encounter rate for L. l. malabaricus is 0.21 animals/km.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Two long-term studies have been conducted on the ecology and behavior of this species in India, and one such study has been conducted in Sri Lanka (Nekaris and Bearder 2006; Radhakrishna and Singh 2004); L. l. nordicus is also very well studied in captivity (Schulze and Meier 1995). They are primarily insectivorous (Nekaris and Jayewardene 2004). Loris lydekkerianus nordicus is apparently able to survive well near human habitations (Nekaris and Jayewardene 2003), as it was found more often associated with disturbed human habitation than with forest (Nekaris and Jayewardene 2004); similar trends in India were found by Singh et al. (1999) and were associated with agricultural pest abundance. The highest densities of lorises on Sri Lanka occurred in the dry zone forests; also, the presence of species of this genus is positively associated with insect presence, and negatively associated with secondary forest with little undergrowth (Nekaris and Jayewardene 2004; Kumara et al. 2006). L. l. nordicus and L.l. lydekkarianus seem to rely heavily on undergrowth, and are often found in secondary growth forest (Nekaris and Jayewardene 2004; Radhakrishna and Singh 2002). Singh et al. (1999) found that relatively open forest and adjoining croplands are the preferred habitat types of lorises in the Dindigul Forests of Tamil Nadu, India. L. l. malabaricus is found to occur more in cardamom plantations and in degraded and stunted rainforests than in primary rainforests (Kumara et al. 2006).

This species is characterized by a multiple-male/multiple-female social system of spatial overlap. They sleep in groups of up to 7 individuals and interact commonly throughout the night (Nekaris 2006; Radhakrishna 2001).
Systems: Terrestrial

Threats [top]

Major Threat(s): Severe habitat loss in Sri Lanka and India has threatened this species there (Nekaris and Jayewardene 2003; Nekaris and Schulze 2005; Nekaris and Bearder 2006). Other threats in Sri Lanka and India include road kills, electrocution on un-insulated power lines, capture for pet trade and use in traditional “medicine,” and killing due to superstitious beliefs (Nekaris and Jayewardene 2003).

Conservation Actions [top]

Conservation Actions: This species is listed in CITES – Appendix II, and classified under Schedule I of the Indian Wildlife Act (1972). In India, very few populations are found in protected areas, and the majority of the population occurs in private lands and commercial plantations (M. Singh pers. comm.).

Further studies of behavior and ecology are needed to better understand the habitat requirements of all the slender loris taxa (Nekaris and Jayewardene 2004). Singh et al. (1999) also suggests more detailed surveys in different forest blocks and habitat types in order to obtain quantitative data on densities and distribution. In Sri Lanka a conservation education programme has been launched in order to increase awareness about the taxa (Nekaris 2003).

Bibliography [top]

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

Kumara, H. N., Singh, M. and Kumar, S. 2006. Distribution, Habitat Correlates, and Conservation of Loris lydekkerianus in Karnataka, India. International Journal of Primatology 27(4): 941-969.

Nekaris, K. A. I. 1997. A preliminary survey of the slender loris (Loris tardigradus) in South India. American Journal of Physical Anthropology 24: 176-177.

Nekaris, K. A. I. 2003. Rediscovery of the slender loris in Horton Plains National Park, Sri Lanka. Asian Primates 8(3): 1-7.

Nekaris, K. A. I. 2006. Social lives of adult mysore slender lorises (Loris lydekkerianus lydekkerianus). American Journal of Primatology 68(12): 1171-1182.

Nekaris, K. A. I. and Bearder, S. 2007. The strepsirrhine primates of Asia and Mainland Africa: diversity shrouded in darkness. In: S. K. Bearder, C. Campbell, A. Fuentes, K. MacKinnon and M. Panger (eds), Primates in Perspective, pp. 24-45. Oxford University Press, Oxford, UK.

Nekaris, K. A. I. and de Silva, G. W. In press. The Primates of Sri Lanka. WHT Press, Colombo, Sri Lanka.

Nekaris, K. A. I. and Jayewardene, J. 2003. Pilot study and conservation status of the slender loris (Loris tardigradus and L. lydekkerianus) in Sri Lanka. Primate Conservation 19: 83-90.

Nekaris, K. A. I. and Jayewardene, J. 2004. Distribution of slender lorises in four ecological zones in Sri Lanka. Journal of Zoology (London) 262: 1-12.

Nekaris, K. A. I. and Jayewardene, J. 2004. Survey of the slender loris (primates: Lorisidae Gray, 1821: Loris tardigradus Linnaeus, 1758 and Loris lydekkerianus Cabrera, 1908) in Sri Lanka. Journal of Zoology (London) 262(4): 327-338.

Radhakrishna, S. 2001. The social behavior of the Mysore slender loris (Loris tardigradus lydekkerianus). Thesis, University of Mysore.

Radhakrishna, S. and Singh, M. 2002. Activity schedule and habitat use of the slender loris (Loris tardigradus lydekkerianus). Journal of the Bombay Natural History Society 99: 400-407.

Radhakrishna, S. and Singh, M. 2002. Conserving the slender loris (Loris lydekkerianus lydekkerianus). National Seminar on Conservation of Eastern Ghats, March 24-26, 2002: 227-231.

Radhakrishna, S. and Singh, M. 2004. Reproductive biology of the slender loris (Loris lydekkerianus lydekkerianus). Folia Primatologica 75(1): 1-13.

Rao, P. 1994. Occurrence of the slender loris Loris tardigradus in south coastal Andhra Pradesh, India. Journal of the Bombay Natural History Society 91(2): 303.

Schulze, H. and Meier, B. 1995. The subspecies of Loris tardigradus and their conservation status: a review. In: L. Alterman, G. A. Doyle, and M. K. Izard (eds), Creatures of the Dark: The Nocturnal Prosimians, Plenum Press, New York, USA.

Singh, M., Kumar, M. A., Kumara, H. N. and Mohnot, S. M. 2000. Distribution and conservation of slender lorises (Loris tardigradus lydekkerianus) in southern Andhra Pradesh, South India. International Journal of Primatology 21(4): 721-730.

Singh, M., Lindburg, D. G., Udhayan, A., Kumar, M. A. and Kumara, H. N. 1999. Status survey of slender loris Loris tardigradus lydekkerianus in Dindigul, Tamil Nadu, India. Oryx 33(1): 31-37.

Citation: Nekaris, A., Singh, M. & Kumar Chhangani, A. 2008. Loris lydekkerianus. In: The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 29 August 2015.
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