Slender lorises  (Loris tardigradus and Loris lydekkerianus)

The most distinguishing characteristics of the slender lorises are their very long, slender arms and legs, which give these species their names (4). They usually have a grey or reddish coat, although this varies according to subspecies, and the fur is soft, thick and woolly. Slender lorises do not have tails and move on all fours climbing or walking along branches (5). They do not have truly opposable thumbs and are only able to grasp things like food or branches with the whole hand, though they do have an extremely powerful grip (2). The eyes are large and round and the prominent ears are thin, rounded and naked at the edges (5). There is much confusion over slender loris classification (2).

L. lydekkerianus ssp. lydekkerianus and L. lydekkerianus ssp. malabaricus are endemic to India, while the other four subspecies, L. lydekkerianus ssp. grandis, L. lydekkerianus ssp. nordicus, L. tardigradus spp. nyctoceboides and L. tardigradus spp. tardigradus are endemic to Sri Lanka (3).

Slender lorises inhabit various habitats, including wet and dry zones, lowland and highland forests (4).

Slender lorises are nocturnal and arboreal, spending daylight hours sleeping on branches or hollow trees (3). By night they move slowly and stealthily in the trees, and catch their prey by quietly stalking it and grabbing it with two hands. Slender lorises have large eyes which provide them with excellent night vision and, like the lemurs, have an excellent sense of smell (5). The muzzle is elongated with an area of moist, glandular skin around the nostrils (2), and it is this that heightens their sense of smell which is useful for foraging. Their diet consists of insects, small vertebrates, birds' eggs, fruit, shoots and young leaves (5). To maximize protein and nutrient uptake, lorises consume every part of their prey including the scales and the bones (4).

These prosimians usually live alone or with a mate. Females enter oestrous twice a year and are receptive for about a week (5). The gestation period lasts for 166-169 days, after which the female gives birth to one or two young (5). Males leave their natal area at maturity to establish their own territories, though female offspring typically stay within their mother's territory, and only leave to establish their own range when they become reproductively active (5).

These species are threatened in India and Sri Lanka by habitat loss and habitat degradation (1). Forest clearance for logging, agriculture and development results in fragmented habitats for loris populations and reduced food and shelter (4).

There are many protected reserves throughout India and Sri Lanka. However, following reports of dwindling primate populations, their success appears limited (6). A detailed survey (2003) on the status and distribution of south-Asian primates may be helpful in informing conservation measures in the future (6). The research recommended habitat management and public education as priorities in the conservation of South Asian primates. Captive breeding was not considered an important tool in the long term protection of Asia's primates, not because of its lack of importance, but due to inadequacies in previous programmes in the region (6). At the current rate of habitat destruction in this region, the slender lorises may become extinct within a few decades. Like so many species its future is dependent on human intervention and the protection of its forest habitats (6).

For more detail on the conservation of this species see:

Status of South Asian Primates: Conservation Assessment and Management Plan (CAMP) Workshop 2003. Summary report available online:
http://www.zooreach.org/Conservation/CAMP/Primate%20CAMP%20summary.pdf

Authenticated (30/04/05) by Matt Richardson, independent primatologist and writer.