The binturong (Arctictis binturong) is a large, shaggy mammal native to the dense tropical rainforests of South and Southeast Asia. It is a robust animal, characterized by a long, muscular body and a thick coat of dark fur. The binturong spends the majority of its life high in the forest canopy, moving slowly and deliberately through the branches.
Classification and Physical Characteristics
The binturong belongs to the family Viverridae, which places it among the civets, genets, and linsangs, despite its common moniker, the “bear-cat.” It is neither a bear nor a true cat, but it is the largest species within its family. The binturong is the sole member of its genus, Arctictis.
Its body is covered in coarse, shaggy fur that is typically black or dark brown, often with tips of gray or white that give it a grizzled appearance. The head is distinguished by small, rounded ears topped with prominent tufts of black hair and long, white whiskers. An adult binturong measures approximately 61 to 96 centimeters (24 to 38 inches) in head and body length, with its tail adding nearly the same length. These animals are quite heavy for an arboreal mammal, weighing between 9 and 20 kilograms (20 and 44 pounds).
Unique Adaptations and Behavior
A defining characteristic of the binturong is its long, muscular prehensile tail, which it uses as a fifth limb. This species is one of only two carnivorous mammals in the world to possess a fully prehensile tail, an adaptation that aids significantly in navigating the complex forest canopy. The tail is thick at the base and tapers toward the end, where a specialized patch of rough, leathery skin provides extra traction for gripping branches.
The binturong is predominantly arboreal, moving with a slow, cautious ambling gait as it climbs through the trees. It is too heavy to jump between large gaps, so it must descend or use its tail and flexible ankles to maneuver.
Both sexes possess scent glands near the tail, which they use to mark their territory. This marking produces a distinctive odor often described as smelling like hot, buttered popcorn. Researchers have identified the volatile compound responsible for this unique smell as 2-acetyl-1-pyrroline, the same chemical created during the Maillard reaction that gives popcorn its aroma. This chemical signal informs other binturongs of an individual’s presence and sex.
Ecology, Diet, and Range
Binturongs inhabit the canopies of tall, dense, tropical forests and lowland evergreen forests across a wide range in South and Southeast Asia. Their geographical distribution extends from Nepal and India eastward through countries like Thailand, Laos, Vietnam, Malaysia, and into the Indonesian islands of Sumatra and Java, and the Philippine island of Palawan. They are primarily nocturnal and crepuscular, meaning they are most active during the twilight hours of dawn and dusk.
The species is classified as a carnivore, but its diet is largely omnivorous, with a strong emphasis on fruit. They are considered highly frugivorous, with figs, especially the strangler fig, being a major food source. They supplement their diet by opportunistically consuming eggs, small birds, rodents, fish, and carrion.
The binturong plays an ecological function as a seed disperser, particularly for the strangler fig. Their digestive system is uniquely capable of breaking down the fig seeds’ tough outer coating, which helps facilitate germination after the seeds are passed.
Conservation Status and Threats
The binturong population has declined by more than 30% over the last three decades, leading the International Union for Conservation of Nature (IUCN) to list the species as Vulnerable. This decline is largely a result of extensive habitat loss and degradation across its range. Deforestation driven by logging, agricultural expansion, and the conversion of lowland forests into plantations, such as those for palm oil, has severely fragmented their living areas.
The species is also significantly impacted by the illegal wildlife trade. Binturongs are captured for the exotic pet market, and their parts are sometimes sold for use in traditional medicine or for their meat in local markets.