Slow Loris - Distribution and Diversity

Distribution and Diversity

Slow lorises are found in South and Southeast Asia. Their collective range stretches from Northeast India through Indochina, east to the Sulu Archipelago (the small, southern islands of the Philippines), and south to the island of Java (including Borneo, Sumatra, and many small nearby islands). They are found in India (Assam and other states of northeastern India), China (Yunnan province), Laos, Vietnam, Cambodia, Bangladesh, Burma, Thailand, Malaysia, the Philippines, Indonesia, Brunei, and Singapore.

There are currently five recognized species. The pygmy slow loris (N. pygmaeus) occurs east of the Mekong river in Yunnan, Laos, Vietnam, and Cambodia. The Bornean slow loris (N. menagensis) is found on Borneo and nearby islands, including the Sulu Archipelago. The Javan slow loris (N. javanicus) is only found on the island of Java in Indonesia. The Sunda slow loris (N. coucang) occurs on Sumatra and the Malay Peninsula, including Singapore and southern Thailand (the Isthmus of Kra). The Bengal slow loris (N. bengalensis) has the largest distribution of all the slow lorises and can be found in Bangladesh, Cambodia, southern China, Northeast India, Laos, Burma, Thailand, and Vietnam.

Slow lorises range across tropical and subtropical regions and are found in primary and secondary rainforests, as well as bamboo groves and mangrove forests. They prefer forests with high, dense canopies, although some species have also been found in disturbed habitats, such as cacao plantations and mixed-crop home gardens. Due largely to their nocturnal behavior and the subsequent difficulties in accurately quantifying abundance, data about the population size or distribution patterns of slow lorises is limited. In general, encounter rates are low; a combined analysis of several field studies involving transect surveys conducted in South and Southeast Asia determined encounter rates ranging from as high as 0.74 lorises per kilometer for N. coucang to as low as 0.05 lorises per kilometer for N. pygmaeus.