What nocturnal primate from Southeast Asia has large eyes and a slow climbing movement? The answer is the slow loris. Slow lorises are several species in the genus Nycticebus, a group of strepsirrhine primates found across South and Southeast Asia.
Their oversized, forward-facing eyes provide strong low-light vision, aided by a reflective layer called the tapetum lucidum. Slow lorises move through the canopy with deliberate, nearly silent steps, often keeping three limbs attached to a branch while reaching with the fourth. This careful climbing helps them avoid detection and maintain a powerful grip.
Slow lorises are not lemurs, bushbabies, or tarsiers, although all are nocturnal or may resemble one another at a glance. Their name describes their unhurried locomotion, not laziness. A remarkable and uncommon primate trait is also found in this group: secretions from an arm gland can be mixed with saliva to produce a toxin delivered through a bite. Habitat loss and the illegal pet trade threaten many slow-loris species.