By Siti Nurleily Marliana and Rahmia Nugraha, 17th December 2025
The bear cuscus Ailurops ursinus is an adorable species—an arboreal marsupial that inhabits the forests of Sulawesi and its surrounding islands. With their large, round, fluffy bodies, they seem to live life at an enviably leisurely pace. If glimpsed while crossing a forest path, their curiously penetrating eyes may make you stop in your tracks and wonder what secrets stir in the canopy. Their charisma alone should be enough to make any researcher want to learn more about them. In fact, one might expect that with such lovable traits, the bear cuscus would be among the most beloved and well-known species in Indonesia. And yet, it attracts far less attention than it deserves. Not only is the marsupial an obscure oddity, but surprisingly little is known about it beyond recent investigations into its morphology and behaviour. There is a paucity of ecological data on the bear cuscus, and this may explain why it holds no legal protections, despite the omnipresent dangers of deforestation and poaching. Without such data, what case can be made for protecting the species?
An adult female with a juvenile (left) and an adult male bear cuscus (right) observe the humans below. Photos: Rahmia Nugraha.
These concerns were the driving force behind our research. Our aim was to identify areas of suitable habitat for the bear cuscus and determine its potential distribution in South Sulawesi, to pinpoint priority areas for the species’ conservation. To find the answers to our questions, we used a method called maximum entropy modelling, which predicts where a species might live based on the conditions in places where it is already known to occur. We collected occurrence data in two protected areas of South Sulawesi, both of which are already experiencing anthropogenic pressures. Doing so required some creativity, resilience and adaptability as the terrain in our study landscape was at times nearly impenetrable. Each site presented its own challenges, from towering karst formations and lack of trails to journeys without phone signal and ventures into areas undocumented for the bear cuscus. Thankfully, we found our way with the help of a guide and several local residents, who also shared their insights into how local people have interacted with the bear cuscus.
The South Sulawesi landscape. Sampling required traversing through these karst towers and making our own trekking routes. Note the presence of rice fields (top) and fences over open land (bottom), both of which impede the bear cuscus’ movement. Photos: Rahmia Nugraha.
Our results showed that the vast majority—over 92%—of our study area was unsuitable as bear cuscus habitat, with much of the remaining habitat occurring in small, disconnected patches. It’s worth noting that we only covered the southern half of South Sulawesi in our modelling; the north, we discovered, is entirely unsuitable because of the scale of human impacts there. Even within the areas we identified as priorities for conservation, we found that much of the potential habitat was subject to high levels of human disturbance. Mining is of particular concern and has expanded rapidly over the past two decades. The cumulative impact of human activities means that the bear cuscus is now restricted to a fraction of the province, with no means of dispersal outside its current areas. Furthermore, in areas where the bear cuscus may be found, deforestation is an ongoing threat, reducing habitat connectivity and exposing the bear cuscus to additional dangers such as poaching.
Left: A guide, a local resident, and students from Alauddin State Islamic University of Makassar and Makassar Forestry Vocational High School, who aided us during sampling. From left to right: Rahmia Nugraha, Fajar Syahrul Syawaluddin, Mr Pado, Ahmad Fayyaadh, Adin Ayu Andriyani, Ahmad Fajar, Mr Tingkang, Rahmat Fajrin Alir and Busyairi Basri. Right: Rahmia photographs a bear cuscus. Photos: Rahmia Nugraha.
The bear cuscus is an elusive species, and they certainly demonstrated this during our efforts to study them. Beyond the challenging terrain, our greatest difficulty was spotting the animals in their natural habitat. Individuals often hide among dense foliage high in the trees and remain perfectly still, which makes visual observation particularly tricky. We only managed to encounter the first individual on the tenth day of searching. One of our most exhilarating experiences was finding a joey outside its mother’s pouch. Fragile and moving hesitantly with a still undeveloped grip, it vocalized constantly in search of its mother. In this exceedingly rare moment, we observed firsthand a bear cuscus adapting and learning how to survive alone in the wild. It was profoundly moving. Once they get a handle on life, bear cuscuses are calm creatures. And once spotted, they are easy to observe and, unfortunately, to catch. In our conversations with local people we learned the fate of captured bear cuscuses: they are eaten, sold in the bushmeat market, traded for livestock or simply fed to pets. As elusive as it may be, the bear cuscus is widely known to be hunted, even in protected areas.
A joey clings to a branch (left), while a juvenile yawns in the midst of eating. Photos: Rahmia Nugraha.
First and foremost, we hope our findings will encourage the Indonesian government to institute legal protections for the bear cuscus. Our results also suggest that the species’ conservation status on the IUCN Red List should be reassessed, to account for the changes in its legal status and the rapid decline of Sulawesi’s forests.
Biodiversity conservation faces significant challenges on islands such as Sulawesi, where it competes with human needs for food, economic resources, and for land itself. As increasing demands from people create pressure to expand extractive activities ever further into the island’s remaining forests, continued advocacy for the protection of natural habitats is vitally important—not only for the sake of the lovable bear cuscus alone. To protect the bear cuscus is to safeguard the rich, unique and irreplaceable endemic biodiversity for which Sulawesi has long been known and valued far beyond its shores.
The article ‘A species under siege: modelling habitat suitability for the bear cuscus Ailurops ursinus in South Sulawesi’ is available open access in Oryx—The International Journal of Conservation.
