Red Slender Loris
(Loris tardigradus)
The slender loris has extremely thin arms and legs. Its face is dominated by huge round eyes which give it excellent night vision and enable it to hunt for insects during the night. Populations of this small primate are declining because their forest habitats are being destroyed for logging, agriculture and development.
Urgent Conservation Actions
Habitat restoration and the establishment of corridors between heavily fragmented forest patches. Education and awareness programmes for local people.
Sri Lanka.
Slender loris eyes are deemed to have medicinal value. The animals’ faces are held close to a scorching flame, causing them to shed tears. Sometimes they are held to a fire until their eyeballs burst. The liquid is collected as it runs out and used in traditional charms and love potions.
Associated Blog Posts
26th Sep 12
The Montane Evergreen Forests (MEF) of Sri Lanka will soon be expanding. This is great news for the Horton Plains slender loris (HPSL), a subspecies which i...  Read

16th Sep 11
Taking a trip to a primary school to join up with a Tuk Tuk rally to do some tree planting was not part of our original plan to launch our forest corrido...  Read

12th Sep 11
The Horton Plains slender loris, also known as montane loris (Loris tardigradus nyctoceboides) is bizarre and adorable all at once. It did a disappearing act...  Read

13th Jun 11
Note: Thank you to everyone who supported this campaign and helped us reach our target! if you would like to keep supporting EDGE project consider a monthly ...  Read

21st Jan 11
Last week two EDGE Fellows, Werner Conradie and Saman Gamage visited London to speak at the Zoological Society of London’s Communicating Science event:...  Read

19th Jul 10
A massive occupancy monitoring programme has been initiated over the past 18 months to assess the persistence of lorises in over 100 of the remaining fragmen...  Read

Evolutionary Distinctiveness
Order: Primates
Family: Lorisidae
The Lorisidae comprises the African angwantibos and pottos and the Asian lorises. These species are thought to share a common ancestor with the bushbabies of Africa (the Galagidae) and the lemurs of Madagascar. The fossil record of the lorids extends back to the Early Miocene (20 million years ago). In the past there has been considerable confusion over slender loris classification. Most authorities now recognise two species of slender loris: Loris tardigradus (with 2 subspecies, both occurring in Sri Lanka) and Loris lydekkerianus (with 4 subspecies, occurring in both India and Sri Lanka).
Head and body length:116-170 mm
No external tail
Weight: 103-172 g
The slender loris is so-named because of its long, slender arms and legs. L. tardigradus is smaller than its relative the grey slender loris (L. lydekkerianus). Its small face is dominated by huge round eyes and prominent ears, which are thin, rounded and hairless at the edges. The soft dense fur is a grey or reddish-brown colour on the back, depending on the subspecies. The underside is whitish-grey. The species has no tail. The highland slender loris (L. t. nycticeboides) has shorter, thicker limbs relative to body length, a larger head, and thicker fur which completely covers the ears. It superficially resembles the Asian slow loris (Nycticebus coucang).
This species is among the most social of the nocturnal primates. During daylight hours the animals sleep in groups in branch tangles, or curled up on a branch with their heads between their legs. At night the animals go their separate ways, moving slowly and silently through the trees in search of food. The red lorises differ from their grey congeners in their frequent use of rapid arboreal locomotion, despite their reputation of being slow and sloth-like. Their large eyes provide them with excellent night vision. Although they are primarily insectivorous, lorises also eat gum, bird’s eggs and small vertebrates, such as geckos and lizards. They consume every part of their prey, including the scales and bones.

Very little is known about the social organisation of this primate. Mating takes place throughout the year, with no reproductive seasonality. The gestation period is 166-169 days, after which time the females give birth to one or two young. The young are nursed for 6-7 months. The lifespan of this species is believed to be around 15-18 years in the wild.
The red slender loris (L. t. tardigradus) favours primary and secondary low land rainforest, moist monsoon forests in the transitional zones and some analogue forests (up to 900 m in altitude), in the south western wet-zone. Reports from the 1960s suggest that it once also occurred in the coastal zone. However, recent surveys have failed to locate any individuals and the subspecies is now thought to be extinct in coastal forests.

The highland slender loris (L. t. nycticeboides) is generally found in the undisturbed canopy of montane cloud forest and moist montane forests (1,800–2,300 m altitude).
Endemic to Sri Lanka. The red slender loris (Loris tardigradus tardigradus) is distributed in the south and southwestern parts of the country, in the tropical rainforests and intermonsoon forests of the wet zone of Sri Lanka.

The highland slender loris (L. t. nycticeboides) is known only from the central highlands of Sri Lanka. It has been observed in five forest patches to date: Horton Plains National Park, Peak Wilderness Sanctuary, Haggala Strict Natural Reserve, Pattipola forest reserve, and Bomuruella forest reserve.
Population Estimate
Population estimates suggest that there are approximately 1,500 animals of L. t. tardigradus in 3,000 ha of extremely fragmented forests, and about 80 animals in Horton Plains of L. t. nycticeboides (the total population of L. t. nycticeboides is unknown).
Population Trend
Loris. t. tardigradus is classified as Endangered (EN A2cd+4cd; C1) and L. t. nycticeboides is classified as Endangered (EN A2cd+4cd; B1ab(i,ii,iii,iv,v)) on the 2010 IUCN Red List of threatened species.
Both subspecies are declining as a result of habitat degradation and fragmentation. Forests in Sri Lanka are rapidly being cleared for logging, agriculture (particularly tea, rubber, cinnamon and oil palm plantations) and human settlement, leaving slender loris populations stranded in poor quality forest fragments, where there is often insufficient food and shelter. The use of agricultural pesticides may be reducing the quantity of insect prey in some areas, and accumulation of some insecticides is thought to be negatively affecting lorises. Current geological surveys have reported that the Horton Plain and other montane peaks contain high levels of lead pollution and there are fears that this may be leading to decreased fertility in the lorises that occur there. Over-collection of firewood is also causing a problem because villagers are not only collecting dead wood but also cutting down the under-story plants, many of which contain seedlings of important cloud forest trees. There are also reports of the slender lorises being electrocuted on power lines, or killed while crossing roads.
Conservation Underway
The species is protected by law in Sri Lanka, and is listed on Appendix II of CITES.

L. t. tardigradus occurs in several protected reserves in Sri Lanka, but remains at risk from habitat destruction due to illegal logging within these reserves. A few individuals of this subspecies are kept in captivity. Many populations occur outside of protected areas.

L. t. nycticeboides occurs in the Horton Plains National Park and possibly in the Peak Wilderness Sanctuary (Sabaragamuwa Province), although more research is needed to confirm its presence here. Sri Lankan researchers are currently carrying out a long-term study into the conservation status of this subspecies.

LORRIS (Land Owners Restore Rainforest in Sri Lanka) is a non-governmental organisation established in 2002 by scientists and landowners in the Pitigala area of Sri Lanka. LORRIS landowners hoping to save what remains of the country’s wet zone rainforests have pledged a portion of their private land to reforestation and a corridor project connecting remaining rainforest on either side of the boundary of Galle and Kaluthara districts in the southwestern lowland areas of Sri Lanka. Over 7000 seedlings have already been planted as part of this scheme. The organisation is also currently undertaking education and awareness programmes in the project locality, and encouraging local farmers to switch to sustainable community-based timber cultivation, and grow lesser known edible fruits, spices and medicinal plants, as well as helping to boost the income of local farmers through ecotourism activities.

The Primate Conservation Society of Sri Lanka was established by a group of young Sri Lankan researchers to promote the conservation of the country’s primates (particularly lorises) and implement research activities that will lead to their long-term conservation. The society now counts as members an international team of primatologists. Members of this society are currently mapping the distribution of the slender loris in the wet zone of Sri Lanka and implementing education and awareness programmes for local people.

This project supports in-country EDGE Fellows to help conserve relevant EDGE species

The red slender loris (Loris tardigradus) is a nocturnal primate and has been the focus of considerable research interest over the past decade. However, despite this interest only limited data are available for the accurate evaluation of their conservation status or applied management needs. A group of committed experts and interested parties gathered in February 2009 to determine priority areas to which conservation research funding should be applied. Within the scope of a single year of funding a focus has been placed on provision of required skills training, resolution of key research questions achievable within such a timeframe (species distribution, range and taxonomy), the development of baseline data and a data management and analysis systems to offer a robust measure of change in habitat patch occupancy over time. Provision of training materials and opportunities to develop technical capacity in potential partner organizations such as the Department of Wildlife Conservation (DWC) and the Forestry Department (FD) as well as within educational establishments will also be a significant component of the project.

Finally, a conservation action plan will be generated in concert with findings of field research, and interactions with management agencies that will hopefully act as a guiding foundation document for national commitment to applied conservation management of loris habitat and populations, if deemed necessary by the Sri Lankan Loris Conservation Group following outcomes of this study.

Conservation Proposed
The most important conservation measures proposed are a reduction in habitat loss and the establishment of corridors between heavily fragmented forest patches. Education and awareness programmes are important to reduce illegal logging, instances of human-induced forest fires, pesticide usage and illegal encroachment, and to reduce the extraction of seedlings as firewood. Further detailed surveys of the status and distribution of the species are required so that important areas of habitat can be identified and protected. Behavioural and ecological studies are also needed in order to estimate the habitat requirements of the different taxa of slender loris.

LORRIS is currently fundraising to restore key slender loris habitat in the montane region of Sri Lanka (Hatton and Adams Peak). More than 1000 acres of private land plus 400 acres of State-owned scrub land will allocated for this project, which aims to create a forested corridor between the Peak Wilderness Sanctuary and the Ambagamuwa forest. The organisation also hopes to create Sri Lanka’s first field based Primate Study Centre in the project locality. Funding is urgently needed to enable LORRIS to complete this important project.
Associated EDGE Community members

Vijitha works on the slender loris in Sri Lanka

Vijitha is our EDGE Fellow currently working on a project to conserve the Slender loris in Sri Lanka

Kelly is a primatologist who has conducted numerous projects on the Slender loris

Kelly has been involved with research projects and numerous species of loris

Lilia is actively involved with slender loris conservation in Sri Lanka

Saman is president of both LORRIS and PCSSL in Sri Lanka

Wasantha is an advisor to the Ministry of Environment and Nature resources of Sri Lanka and treasurer of LORRIS

Craig recently co-led the Negros Interior Biodiversity Expedition in the Philippines

Land Owners Restore Rainforest in Sri Lanka (LORRIS)
A non-governmental organisation established in 2002 by scientists and landowners in the Pitigala area of Sri Lanka. Current work includes habitat restoration and corridor projects in keys areas of red slender loris habitat as well as educational and outreach programmes in communities within Sri Lanka’s threatened wet zone.
Contact Saman Gamage (samangam2004@yahoo.com) or Sunil Wimalasuriya (daybat@celltelnet.lk)

Primate Conservation Society of Sri Lanka
Established to help protect all of Sri Lanka’s threatened primates, members of this society are currently mapping the distribution of the slender loris in the wet zone and implementing education and awareness programmes for local people.
Contact Saman Gamage (samangam2004@yahoo.com) or Wasantha Liyanage (wasantha_liyanage@yahoo.com)

Conservation database for prosimian primates
This non-commercial database for conservation of lorises and pottos containing current literature on these species is hoped to create increased awareness for these threatened species.

ARKive. (Jan 2006).

Anonymous. 2002. Opinion 1995 (Case 3004). Lorisidae Gray, 1821, Galagidae Gray, 1825 and Indriidae Burnett, 1828 (Mammalia, Primates): conserved as the correct original spellings. Bulletin of Zoological Nomenclature 59:65-67.

Gamage, S. 2007 (pers. comm.)

Groves, C. P. 1998. Systematics of tarsiers and lorises. Primates. 39(1): 13-27

Nekaris, K.A.I. 2006. (pers. comm.).

Nekaris, K.A.I. 2002-03. Rediscovery of the Ceylon Mountain slender loris in the Horton Plains National Park, Sri Lanka. Asian Primates 8(3-4): 1-7.

Nekaris, K.A.I. 2003. Observations on mating, birthing and parental care in three taxa of slender loris in India and Sri Lanka (Loris tardigradus and Loris lydekkerianus). Folia Primatologica, supp. (eds. S. Gursky and KAI Nekaris). 74:312-336.

Nekaris, A. 2008. Loris tardigradus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. www.iucnredlist.org. Downloaded on 14 November 2010.

Nekaris, K.A.I.; 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 262(4): 327-338.

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., Liyanage, W.K.D.D. & Gamage, S. 2005. Relationship between forest structure and floristic composition and population density of the Southwestern Ceylon slender loris (Loris tardigradus tardigradus) in Masmullah Forest, Sri Lanka. Mammalia 69(2): 1-10.

Nekaris, K.A.I. & Stephens, N.J. 2007. All lorises are not slow: rapid arboreal locomotion in the newly recognised red slender loris (Loris tardigradus tardigradus) of southwestern Sri Lanka. American Journal of Primatology. In press.

Nowak, R.M. 1999. Walker’s Mammals of the World. Sixth edition. The Johns Hopkins University Press, Baltimore and London.

Distribution map based on data provided by the IUCN Global Mammal Assessment.

if you can provide new information to update this species account or to correct any errors, please email us at info@edgeofexistence.org

Forum comments

There are as yet no comments for this species.

Add a comment

You must log in to post. If you don't have a login, it's easy to register.