Loris tardigradus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Loris tardigradus
Species Authority: (Linnaeus, 1758)
Infra-specific Taxa Assessed:
Common Name(s):
English Red Slender Loris, Slender Loris
French Loris Grèle
Spanish Loris Fino
Loris ceylonicus Fischer, 1804
Loris gracilis É. Geoffroy, 1796
Loris zeylanicus Lydekker, 1905
Taxonomic Notes: This taxon formerly included Loris lydekkerianus, which has been recently been promoted to full species status (Groves 2001). There is preliminary evidence for two additional subspecies in the Wet Zone of Sri Lanka (Nekaris et al. 2006). The form nycticeboides is a taxonomic variant of tardigradus and not lydekkerianus.

Assessment Information [top]

Red List Category & Criteria: Endangered C2a(i) ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Nekaris, A.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
Listed as Endangered because its population size is estimated to number fewer than 2,500 mature individuals, there is an observed continuing decline in the number of mature individuals, and no subpopulation contains more than 250 mature individuals.
2004 Endangered
2000 Vulnerable
1996 Vulnerable (Baillie and Groombridge 1996)
1996 Vulnerable

Geographic Range [top]

Range Description: This species is endemic to central and south-western Sri Lanka, and is typically found in the southern “wet zone” of the island, up to the central “intermediate zone” (Nekaris and Jayewardene 2004).

L. t. tardigradus
Found in south-western Sri Lanka, from Colombo (although no known population still exists in this city) in the north to Ranna on the south coast. The subspecies has recently been recorded at several locations in Sri Lanka: Maimbulakanda Nature Reserve in Gampaha District, Western Province; Oliyagankele Forest Reserve, Masmullah, Kakanadura, Dandeniya Proposed Forest Reserve, Matara District; Kanneliya, Polgahaivalakande, and Kottawa Forest Reserves and Pitigala forest patches, Galle District, Southern Province; and in Godakawela, Ratnapura District, and Sinharaja World Heritage site.

Loris tardigradus nycticeboides
Found in central Sri Lanka, where it is known from the Horton Plains, Nuwara Eliya District, Central Province. Extent of occurrence is less than 300 km2.
Sri Lanka
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: All populations are thought to be in decline. 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. According to Molur et al. (2003) the total population of L. t. nycticeboides is unknown, yet this species has declined by greater than 80% in the last 200 years and is predicted to decline by >20% in the next 10 years. L. t. tardigradus is predicted to decline by greater than 10% in the next 5 years (Molur et al. 2003). These declines are based on the 1:1 relationship between loss of critical habitat and population number. The country has lost 97% of its forest cover (Mill 1995; Myers et al. 2000), thus dramatically reducing the population.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Loris tardigradus tardigradus is found in wet lowland forests (Schulze and Meier 1995), tropical rain, swampy coastal and evergreen forests, and wet zone lowland forest up to 470 m (Molur et al. 2003). Loris t. tardigradus has only been observed to eat animal prey. Although they will eat fruit in a captive setting, they will always choose animal prey first. In addition to insects (including moths, stick insects, dragonflies, beetles, cockroaches, grasshoppers), they relish lizards and geckos. At Masmullah Proposed Forest Reserve, lorises were found in high abundance in areas characterised by Humboldtia laurifolia, a tree that has a mutualistic relationship with ants, providing abundant food for lorises. Lorises occurred at densities of 0.08-0.55 animals/ha across 15 separate sites. Loris abundance was positively associated with vines and branches providing continuous passage, branches of small size (<5 cm) and trees providing a number of potential sleeping sites. Vicinity to human populations negatively impacts this species; it is not found in home gardens, and seems to require continuous canopy to move between forest patches.
Loris t. nycticeboides may possibly be more carnivorous than the lowland subspecies. As is this case with other primates at high altitudes, it also may occur at lower densities. The forest where it occurs has been classified as cloud forest, montane forest and evergreen forest at altitudes greater than 1,500 m (Schulze and Meier 1995), from 1,650 to 2,000 m (Molur et al. 2003). Of actual sightings, the highest was at 2,134 m and the lowest at 1,829 m altitude. Temperatures in its habitat have been recorded from 15.4°C (May/June) to -4°C (Dec/Jan) (Nekaris and Jayewardene 2003; Nekaris et al. 2005; Nekaris and Bearder 2006).
Systems: Terrestrial

Threats [top]

Major Threat(s): The threats imposed by humans on Sri Lankan Loris include habitat loss, road kill, and hunting for the pet trade, traditional “medicine,” and superstitious killing. Also, lorises have been electrocuted on un-insulated power lines. Loris t. tardigradus exists in few isolated forest patches that are also under severe encroachment by humans. Recent population studies estimate low numbers in forest patches and it is evident that both subspecies are in decline (Nekaris 2003, 2006).

Molur et al. (2003) list the following threats for L. t. nycticeboides: “land and water pollution, habitat loss due to agriculture, dairy husbandry, and vegetable cultivation, as well as local and commercial trade for eyes and meat by tea plantation workers, and possible village level trade for folk medicine”. While for L. t. tardigradus major threats are: “deforestation due to urbanization, and local, domestic, and commercial trade for meat” (Molur et al. 2003).

Conservation Actions [top]

Conservation Actions: This species is listed on CITES Appendix II, and is protected under the Fauna and Flora Protection Ordinance Act No. 2, 1937 and subsequent amendments including Act No. 49, 1993 at the species level (Molur et al. 2003).
L. t. tardigradus exists in Sinharaja World Heritage site and seven nature/forest preserves, as well as one proposed forest reserve, while at least one population of L. t. nycticeboides resides in Horton Plains National Park. Despite living in these areas, the survival of the species depends on reduction of habitat loss and the concurrent establishment of corridors between forest fragments. The eradication of local reliance on lorises for traditional “medicine” and use as superstitious scapegoats can only be achieved through education (Nekaris and Jayewardene 2004). Reliable population estimates and a monitoring program are needed for all Sri Lankan loris populations.
Molur et al. (2003) list the following necessary research actions for this species: genetic and taxonomic, life history, population surveying, epidemiology, trade, population genetics, limiting factors, behavior and ecology. Also listed are the following needed management actions: habitat management, wild population management, monitoring, public education, limiting factor management, work in local communities, and Population and Habitat Viability Assessment.

Citation: Nekaris, A. 2008. Loris tardigradus. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 22 December 2014.
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