Ceylon Mountain Slender Loris, Loris tardigradus nycticeboides

Ceylon Mountain Slender Loris
Loris tardigradus nycticeboides (Hill, 1942)
Sri Lanka
(2004)
Specially adapted to the cold nights of its mountainside forests, the Ceylon Mountain slender loris is the rarest and most vulnerable of Sri Lanka's primate fauna.

Four taxa of slender loris, spindly nocturnal primates characterized by short soft fur, no tails, long limbs, and woeful and enormous eyes, are endemic to the critically endangered rainforests of Sri Lanka. Although all taxa have been classified as Endangered, those found in the island's Wet Zone, where only 3% of rainforest remains, are the most imperiled.
Restricted to a potential range of no more than 250 km², or, more realistically, 30 km², the Ceylon Mountain (or Horton Plains) slender loris (Loris tardigradus nycticeboides) is the most extraordinary of the already specialized slender loris taxa. This cold-adapted slender loris' pelage is so thick, it obscures its ears and thickly clothes the animals' otherwise pencil-thin limbs, adapting it to its life in the montane rainforests, where temperatures may drop to -4ºC.

In 1980, the meticulous expert on Sri Lanka's mammals, W. W. Phillips, wrote that the Ceylon Mountain slender loris "would appear to be the rarest of all mammals in Sri Lanka (p. 127)." In fact only four confirmed sightings have been made since 1937, despite several recent systematic surveys in its restricted range by researchers from the Nocturnal Primate Research Group, Oxford Brookes University, and Wildlife Heritage Trust of Sri Lanka.

Although the Horton Plains National Park is officially protected, gem mining, collection of fuelwood, agricultural encroachment, the pet trade, forest diebacks in the park, and stochastic effects on the small isolated forest patches to which it clings, continue to threaten this rarest of Sri Lankan primates.

K. Anna. I. Nekaris

References
Nekaris, K. A. I. 2003. Observations of mating, birthing and parental behaviour in three subspecies of slender loris (Loris tardigradus and Loris lydekkerianus) in India and Sri Lanka. Folia Primatologica 74: 312-336.
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. 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: 1-12.

Suggested citation:
Nekaris, K. A. I. 2005. Horton Plains Slender Loris, Ceylon Mountain Slender Loris, Loris tardigradus nycticeboides (Hill, 1942). In: Primates in Peril: The World's 25 Most Endangered Primates 2004-2006, R. A. Mittermeier, C. Valladares-Pádua, A. B. Rylands, A. A. Eudey, T. M. Butynski, J. U. Ganzhorn, R. Kormos, J. M. Aguiar and S. Walker (eds.), p.25. Report to IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS) and Conservation International (CI), Washington, DC.