The colugo, sometimes called the 'flying lemur' of Southeast Asia, resembles a lemur in appearance, possesses a gliding membrane like a gliding ferret, and spends its nights moving through the forest canopy. However, the colugo is neither a lemur nor a gliding ferret, and it cannot fly.
This unusual mammal from Southeast Asia belongs to its own order. Currently, only two living species are recognized, making the colugo one of the least known and most peculiar mammals in the region.
Colugos are small nocturnal mammals belonging to the order Dermoptera. The two recognized species are the Sunda colugo (Galeopterus variegatus) and the Philippine colugo (Cynocephalus volans). They inhabit forests throughout Southeast Asia, including parts of Indonesia, Malaysia, the Philippines, and Singapore.
They spend almost their entire lives in trees, where their spotted brown or grey fur helps them blend in with trunks and branches. During the day, they can remain almost motionless, pressed against a tree. As soon as night falls, they become active, feeding and moving through the canopy.
What is a Colugo?
The most distinctive feature of the colugo is the patagium—a large skin membrane that stretches between its limbs. Although several mammals can glide, the colugo's membrane is unusually extensive. It extends from the neck along the sides of the body and between the paws, reaching the tail and even covering the fingers and feet.
When the animal jumps from a tree, it unfurls this membrane to glide through the forest. It has been recorded that colugos can glide for distances of about 150 meters, allowing them to move between trees without descending to the forest floor. This is an energy-efficient mode of locomotion that keeps them in the canopy, away from some dangers below.
Despite the nickname, the colugo cannot fly. Unlike birds or bats, it is not capable of generating powered flight; it is a gliding animal that uses gravity and its membrane to control movement in the air.
The unusual anatomy of the colugo is not limited to the gliding membrane. It has specialized teeth called dental crests. Some lower teeth are divided into thin, crest-like projections that help the animal groom itself. This is especially useful for an animal whose enormous membrane is constantly exposed to the tropical forest environment, as dirt, insects, and other debris can settle on it, making membrane cleanliness very important.
Colugos are primarily herbivores. Their diet includes leaves, flowers, and fruits, with leaves forming a significant part of their intake. Their nocturnal lifestyle allows them to feed quietly in the canopy while most of the forest sleeps. Furthermore, they have large eyes suitable for low-light conditions, and their long limbs and sharp claws help them grip tree trunks and branches.
The Sunda colugo is found in parts of mainland and island Southeast Asia, while the Philippine colugo inhabits the southern Philippines. Singapore is one of the more accessible places to encounter the Sunda colugo. Animals have been sighted in several forest areas, including Bukit Timah Reserve and Central Catchment.
However, encountering one is not guaranteed. Colugos are secretive, nocturnal animals, and their camouflage can make them surprisingly difficult to spot on tree bark. Nevertheless, if you look up into the canopy after dark, you might see the animal push off the trunk and silently glide to another tree.
Although there are only two recognized living species of colugo, researchers have discovered significant genetic differences between geographically isolated populations. A 2016 genomic study showed that what is currently classified as two species may contain much greater evolutionary diversity than previously thought. For now, the colugo remains the sole living representative of its own order, alongside its single close relative. It is a strange combination of a gliding mammal, a nocturnal tree dweller, and a primate relative.