Sunda Slow Loris

Sunda Slow Loris

Greater slow loris

Nycticebus coucang
Population size
Life Span
20-24 yrs
599-685 g
227-38 cm

The Sunda slow loris is an arboreal venomous primate native to Southeastern Asia. Like other slow lorises, it has a wet nose (rhinarium), a round head, small ears hidden in thick fur, a flat face, large eyes, and a vestigial tail. The Sunda slow loris has dark rings around its large eyes, a white nose with a whitish stripe that extends to the forehead, and a dark stripe that stretches from the back of the head along the spine. Its soft, thick, woolly fur ranges from light brown to deep reddish-brown, with a lighter underside.






















Generally solitary




Not a migrant


starts with



Biogeographical realms

Sunda slow lorises are found in Indonesia, on the islands of Sumatra, Batam, and Galang in the Riau Archipelago, and Pulau Tebingtinggi and Great Natuna (Bunguran) in the Natuna Islands; in Malaysia on the Malay Peninsula and Pulau Tioman; in the southern peninsular of Thailand; and Singapore. They prefer to live in rainforests with continuous dense canopies and will also live in other types of habitat.

Sunda Slow Loris habitat map

Climate zones

Habits and Lifestyle

Sunda slow lorises are nocturnal primates that rest by day in the forks of trees, or in thick vegetation and feed by night. Unlike other loris species, they remain in trees most of their life and sleep in a ball in branches or foliage. They usually sleep alone but may sleep with several conspecifics (individuals of the same species), including other adults. When threatened with predators, Sunda slow lorises can bite, roll into a ball exposing their toxic saliva-covered fur, or roll up and drop from the trees. However, the primary method of predator avoidance is crypsis (camouflage), whereby it hides. There are eight distinct call types made by Sunda slow loris adults, which can be divided into two categories: contact and contact-seeking calls such as whistles and short keckers (a social play and attention-seeking call), and aggressive and defensive calls such as long keckers, screams, snarls and grunts. Because they rely on crypsis to avoid predators, Sunda slow lorises do not make alarm calls. Infants emit clicks and squeaks when disturbed. During the mating season, females make whistle calls when in visual contact with a male. When exploring new environments and during handling, these animals make ultrasonic vocalizations out of the human hearing range.

Group name
Seasonal behavior

Diet and Nutrition

Sunda slow lorises are omnivores. They eat sap, floral nectar and nectar-producing plant parts, and fruits. They also consume gums and arthropods such as spiders and insects. Gum is taken by licking wounds on trees. Sunda slow lorises are also known to feed on mollusks, including the giant land snail, and birds' eggs.

Mating Habits

192 days
1 infant
16-27 months

In the wild, the mating system of the Sunda slow loris is thought to vary between populations. These primates are polyestrous, having many breeding periods during the year. The gestation period usually lasts about 192 days, after which one infant is born, although twinning has been observed. Baby slow lorises are weaned from their mother at 3-6 months of age and become independent when they are between 16 and 27 months old. Reproductive maturity is reached between the ages of 18 and 24 months in females and can be reached by 17 months in males.


Population threats

The Sunda slow loris is threatened with extinction due to growing demand in the exotic pet trade and has become one of the most abundant primate species on sale at Indonesian pet markets. Its teeth are often pulled out before being sold as pets which can result in infection and/or death, this process makes reintroduction to the wild impossible. It also suffers from habitat loss, which has been severe in the areas in which it is found. Sunda slow lorises are further threatened by gathering for illegal traditional medicine. Their fur is reported to heal wounds, the flesh to cure epilepsy, eyes are used in love potions, and the meat is reported to cure asthma and stomach problems. They are also killed as crop pests.

Population number

The IUCN Red List and other sources don’t provide the number of the Sunda slow loris total population size. Currently, this species is classified as Endangered (EN) on the IUCN Red List and its numbers today are decreasing.

Fun Facts for Kids

  • The Sunda slow loris is commonly known as malu-malu, meaning "shy" in Indonesian, and also as bukang or Kalamasan. It is sometimes called Kuskus, because local people do not distinguish between the slow loris and Cuscus, a group of Australasian possums. In Malaysia they are sometimes known as kongkang or kera duku; 'kera' is Malay for monkey while 'duku' is the fruit-bearing tree. In Thailand, this adorable primate is called ling lom (ลิงลม), which translates as "wind monkey".
  • The Sunda slow loris has a toothcomb, six forward-facing teeth on the bottom jaw, which includes the lower incisors and the canine teeth. The structure is generally used for grooming and to scrape off gum when foraging.
  • The Sunda slow loris is the only venomous primate in Singapore. Like other lorises, it excretes a strong-smelling liquid from glands on the insides of its elbows which is used in communication but it is toxic to humans. The gland is licked to spread scent across their bodies and those of their infants using the toothcomb while grooming.
  • The Sunda slow loris may grin or bare its teeth. When stressed, infants may grin, while adults bear their teeth to show aggression or fear, but also during play.
  • One major distinguishing feature between all loris species is locomotion: the Sunda slow loris moves slowly through trees on all four limbs, typically with three limbs attached to a support at a time. Its movement has been described as unique; similar to crawling, or as if it was climbing in every direction, the Sunda slow loris changes direction or moves between branches with little noise or change in speed. It may also hang below a branch by one or both feet for long periods of time.


2. Sunda Slow Loris on The IUCN Red List site -

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