Sunda Slow Loris, Nycticebus coucang

The Sunda slow loris (Nycticebus coucang), also known as the greater slow loris, is a primate that can be found in Singapore, western areas of Malaysia, southern areas of Thailand, and Indonesia. This species prefers to reside in tropical rainforests but can be found in other habitats. It was first discovered in 1770 by Dutchman Arnout Vosmaer, who described it as a sloth, and was later classified with all other known lorises as a single species. Today, the Sunda slow loris is one of nine distinct species of slow loris, three of which were once thought to be its subspecies.

The Sunda slow loris reaches an average body length between 11 and 15 inches and weight between 21.1 and 24.2 ounces. As is typical to slow lorises, this species has toes that allow it to grip onto branches and a toothcomb, which is uses for grooming and to pull sap from trees. It is known for its unique movements, which are slow and sporadic in appearance. It seems to crawl in all directions and always has at least three limbs attached to a branch at all times.

The Sunda slow loris is nocturnal and spends its life moving about in the thick canopies of rainforests. This species is primarily solitary, although it can be found in male and females pairs. All adult individuals reside in small home ranges that overlap each other and although most have been found sleeping alone, some sleep with other individuals. Although it is a slow moving animal, it consumes food that produces high amounts of energy, including saps, flower nectar, and fruits, among other food types. It is thought that these foods are consumed in order to help it digest toxic secondary plant compounds.

The Sunda slow loris is capable of emitting eight different calls that are separated into contact calls and defensive calls. Contact calls, which include whistles, are used to initiate and engage in contact with other individuals. Defensive calls, which individuals make when aggravated or disturbed, include grunts, screams, and snarls. This species does not emit alarm calls when threatened by predators, because it is able to defend itself using a toxic chemical excreted from the elbow. It rubs this excretion on its fur while grooming. Although it is able to defend itself, its primary means of escaping predators is to hide.

The breeding season of the Sunda slow loris is the only time that many individuals will gather at one time, but these groupings consist of only one female. However, it is not known whether females mate with one or many males. Females will emit a vocalization to alert males that they are ready to breed, after which time they will mate while hanging onto branches. After a pregnancy period of about 192 days, one young or twins are born. Once the young are weaned, they will leave their mother to establish home ranges of their own.

The Sunda slow loris is mainly threatened by the pet trade and it is the most widely traded and sold legally protected animal within its range. Because this species has a high death rate when in captivity, replacement pets are often captured, repeating a dangerous and increasing cycle. It is also captured to be used in traditional medicinal practices and is threatened by extreme habitat loss and habitat fragmentation. The Sunda slow loris appears on the IUCN red List with a conservation status of “Vulnerable.”

Image Caption: A Sumatran Sunda Slow Loris (Nycticebus coucang) clinging to a tree branch at the Duke Lemur Center in Durham, North Carolina. Credit: David Haring/Wikipedia (CC BY-SA 3.0)