Bangka Slow Loris (Nycticebus bancanus) — Rediscovered, Still Fighting for Survival
Opening Story: A Quiet Pair of Eyes at the Edge of the Trees
Welcome. I am EcoSage, your guide across the living world. Picture a warm, humid night on Bangka Island, off the southeastern coast of Sumatra, Indonesia. Where towering lowland rainforest once stood unbroken, a quiet residential lane now borders a backyard garden and a row of power lines. High on a narrow branch, a small, reddish-brown primate no heavier than a grapefruit pauses in the beam of a flashlight. Its round, dark-ringed eyes catch the light. It does not leap or screech; instead, it moves with deliberate, fluid slowness, gripping the bark with pincer-like hands.
For nearly nine decades, formal Western science believed this animal might have vanished from the Earth forever. Yet on the ground in Bangka, local residents looking up into their fruit trees—and the wildlife rescuers answering their late-night phone calls—knew the Bangka slow loris was still here, holding on at the very edge of human neighborhoods.
Quick Facts Card (Nycticebus bancanus)
| Field | Verified Data |
|---|---|
| Common Name | Bangka slow loris |
| Scientific Name | Nycticebus bancanus (Lyon, 1906; elevated to full species status in 2013 by Munds et al.) |
| Class / Order / Family | Mammalia / Primates / Lorisidae |
| Geographic Range | Endemic to Bangka Island (and possibly adjacent Belitung Island; 2013 facial-mask studies also proposed southwestern Borneo / West Kalimantan), off southeastern Sumatra, Indonesia |
| Primary Habitat | Tropical lowland forest fragments; frequently encountered in plantations, backyard gardens, settlements, and along roads where primary forest has been cleared |
| Wild Diet | Coming Soon (Not confirmed in published field studies for N. bancanus specifically; study co-author Timon Glaw notes it likely feeds on insects, tree gums, nectar, and other plant parts like related Nycticebus species) |
| Venomous Trait | Yes — One of the world's only venomous primates; licks a brachial gland near the inside of its elbow to mix secretion with saliva, delivered through a forward-projecting lower toothcomb |
| IUCN Red List Status | Critically Endangered (Possibly Extinct) — Nekaris & Marsh, 2020 assessment (status reassessment pending following the October 2026 Spixiana publication) |
Is the Bangka slow loris extinct?
The Bangka slow loris is alive in the wild today, despite decades of absence from academic journals. In its 2020 assessment, the IUCN Red List classified Nycticebus bancanus as Critically Endangered (Possibly Extinct), citing 1937 as the species' last scientific record—a reference to Dutch zoologist H.J.V. Sody's 1937 work examining museum specimens likely collected between November 1930 and September 1932—and Re:wild included the primate on its Most Wanted Lost Primates list. That nearly 90-year gap in formal literature closed in October 2026, when researchers Langka Sani, Endi Riadi, and Andre Septian of the Alobi Wildlife Rescue Center, together with Jochen Menner of the Taman Safari Prigen Conservation Breeding Ark and Timon Glaw of the Haus des Meeres Aqua Terra Zoo in Vienna, published landmark findings in the zoological journal Spixiana (Vol. 49, Issue 1, pp. 119–128). Their paper documented that between 2015 and August 2025, Alobi rescued more than 90 Bangka slow lorises across all four regencies of Bangka Island as well as the provincial capital, Pangkal Pinang. Following veterinary evaluation, 86 healthy individuals were released back into seven protected forest sites across the island, led by Taman Hutan Raya Bukit Mangkol (37 releases), Taman Wisata Alam Permisan (22 releases), and Taman Hutan Raya Gunung Menumbing (15 releases).
Where does the Bangka slow loris live?
The Bangka slow loris is native to Bangka Island, an island covering roughly 12,000 square kilometers off the southeastern coast of Sumatra in Indonesia's Bangka Belitung province, home to more than one million people. Although first described as a distinct taxon by Marcus Ward Lyon Jr. in 1906 and long treated as a subspecies of the Bornean slow loris (Nycticebus menagensis), it was elevated to full species rank in 2013 by Rachel Munds and colleagues based on distinctive facial-mask coloration and fur patterns; those 2013 museum analyses also suggested its range might extend to neighboring Belitung Island and parts of West Kalimantan in southwestern Borneo. On Eclopidia's interactive map layers—spanning Countries, Habitats, and Mammalia—you can trace how Bangka Island's remaining lowland rainforest pockets, including Gunung Maras National Park, Bukit Mangkol, and Gunung Menumbing, serve as vital refuges not only for Nycticebus bancanus but also for other little-known island endemics such as the Bangkan treeshrew (Tupaia discolor, currently listed as Data Deficient).
Why is the Bangka slow loris Critically Endangered?
Centuries of intensive surface and pit tin mining—including widespread illegal mining operations—combined with large-scale land clearing for oil palm plantations have carved Bangka Island's original primary rainforest into isolated fragments. Because slow lorises are strictly arboreal and cannot cross open ground easily, forest clearance forces them onto utility wires, roadways, and residential fruit trees. In the October 2026 Spixiana study, the authors analyzed 43 rescues recorded with detailed circumstances since 2021, revealing the exact everyday hazards pushing the species toward extinction: 16 individuals had entered houses or backyard gardens, 7 suffered severe electrical burns on uninsulated power lines, 6 were recovered while crossing roads, 5 were confiscated or surrendered from captivity and the local pet trade, 3 were found inside agricultural plantations, 1 became entangled in a fence, and 1 was injured in a dog attack. At least 3 of those rescued individuals died from the severity of their injuries, underscoring how narrow the margin of survival has become whenever forest canopy is replaced by wires and asphalt.
Is the Bangka slow loris venomous, and what does it eat?
Yes—alongside the other members of the genus Nycticebus, the Bangka slow loris belongs to the only known group of venomous primates on Earth. When threatened, the loris raises its arms and licks a specialized brachial gland located near the inside of its elbow, mixing an oily glandular secretion with its saliva to activate a potent toxin. The activated venom is drawn by capillary action into its procumbent lower front teeth—an anatomical structure known as a toothcomb, kept clean by a textured sublingual "second tongue"—allowing the animal to deliver a bite that can cause intense pain, slow-healing tissue necrosis, or life-threatening anaphylactic shock in humans and predators. While the toothcomb also functions as a feeding tool in slow lorises, published wild diet field studies for Nycticebus bancanus specifically have not yet been conducted (marked as Coming Soon on Eclopidia's data card). Study co-author Timon Glaw notes that, like other Nycticebus species, the Bangka slow loris almost certainly feeds on a mix of insects, tree gums and sap gouged from bark, floral nectar, and soft plant parts.
What happens next for the species?
Confirming that the Bangka slow loris still survives is only the opening chapter; keeping it in the wild requires immediate, coordinated science and habitat stewardship. In their 2026 Spixiana assessment, Sani, Riadi, Septian, Menner, and Glaw call for three urgent priorities: establishing a formal in situ forest protection and post-release monitoring program on Bangka Island aligned with IUCN SSC guidelines, conducting systematic island-wide population and genetic surveys to determine how many individuals remain and clarify their relationship to Bornean populations, and building a scientifically managed ex situ conservation breeding ark as an insurance population. Everyone who follows wildlife science can help keep attention on these overlooked island ecosystems: explore Indonesia's threatened mammals across Eclopidia's Conservation hub and Mammalia directory, and read the full multi-source attribution timeline in our companion briefing on EcoAlaxy News Channel™ (ecoalaxynewschannel.com).
Primary Sources & Taxonomic References
- Sani, L., Riadi, E., Septian, A., Menner, J. & Glaw, T. (2026). "Neglected but still alive: Further evidence for the continued existence of the Bangka Slow Loris (Nycticebus bancanus) on Bangka Island, Indonesia (Primates: Lorisidae)." Spixiana, 49(1): 119–128. Original PDF via Pfeil Verlag
- Nekaris, K.A.I. & Marsh, C. (2020). Nycticebus bancanus. The IUCN Red List of Threatened Species 2020: e.T163015864A163015867.
- Munds, R.A., Nekaris, K.A.I. & Ford, S.M. (2013). "Taxonomy of the Bornean slow loris, with new species Nycticebus kayan (Primates, Lorisidae)." American Journal of Primatology, 75(1): 46–56.
- Lyon, M.W. Jr. (1906). "Mammals of Banka, Mendanau, and Billiton Islands, between Sumatra and Borneo." Proceedings of the United States National Museum, 31(1498): 575–612.
- Companion Source Briefing: Bangka Slow Loris Confirmed Alive on Bangka Island After Nearly 90-Year Gap in Scientific Literature — EcoAlaxy News Channel™ (ecoalaxynewschannel.com)