Bengal Slow Loris, Nycticebus bengalensis

The Bengal slow loris (Nycticebus bengalensis), also known as the northern slow loris, is a primate that can be found in Indochina and on the subcontinent of India. Its range includes Bangladesh, Cambodia, Vietnam, and southern areas of Thailand. It prefers to reside in deciduous forests and evergreen forests with thick canopies. This species was classified as a subspecies of the Sunda slow loris until 2001, when genetic evidence was found that supported its classification as a distinct species.

The Bengal slow loris reaches and average body length between 10 and fifteen inches and a weight between 2.2 to 4.63 pounds, making it the largest of all slow loris species. Its thick fur is brownish grey on the back, although seasonal moulting may change this color slightly, and white on the underbelly. It holds a dark stripe on its head that extends vertically. Its forelegs are light in color, while the hind legs vary in color from nearly white to brown. Its flat face, which is pale in color, holds large eyes that are orange in color. Both its hind feet and forefeet help it grip onto branches and each hind foot has a curved second toe, known as a toilet claw, that aids it in grooming and scratching itches.

Like other primates, the Bengal slow loris resides in trees, preferring large and healthy canopies because they provide a stable food source and protection against predators. Because of this, it is a good indicator for gauging the health of a forest. This species primarily consumes plant materials like resins, saps, and gums, making it an important germinator, but it will also consume small birds, reptiles, and snails. It is active during the nighttime hours, resting in tree hollows during the day, and is thought to live in small family groups that hold territories. This species is hunted by many carnivores and has a lifespan of up to twenty years.

The Bengal slow loris is able to breed throughout the year, but is only able to breed once every twelve to eighteen months. Breeding females emit a loud whistle to attract males and after a pregnancy period of six months, they will give birth to one young, although twins do occur. Mothers will carry their young on their backs for up to three months, at which time the young are weaned and sexual maturity is reached at twenty months of age.

The main threats to the Bengal slow loris include illegal trapping and hunting and habitat loss caused by logging, road construction, and slash and burn agricultural practices. This species does occur in some protected areas and is protected by law in some areas of its range. Despite its protections, it has experienced significant habitat and population losses. Because of these factors, the Bengal slow loris appears in the CITES Appendix I and on the IUCN Red List with a conservation status of “Vulnerable.”

Image Caption: Nycticebus bengalensis from Laos with 6-week-old baby. Credit: Helena Snyder/Wikipedia (CC BY-SA 3.0)