The World’s Only Venomous Primate Was Missing From Science for Nearly 100 Years—Then More Than 90 Were Found

For decades, scientists had little new information about one of the world’s most unusual primates. The Bangka slow loris, a small, nocturnal animal with enormous eyes and a rare venom-producing defense, had not appeared in scientific literature for nearly a century. Some conservation assessments even listed the species as possibly extinct.

But the animal had not vanished from the island it calls home.

On Bangka Island in Indonesia, local residents continued encountering these elusive primates in gardens, near roads, and around human settlements. Wildlife rescuers responded to reports, cared for injured animals, and returned many to the forest. Between 2015 and 2025, the Alobi Wildlife Rescue Center documented more than 90 Bangka slow lorises, providing researchers with important evidence that the species was still surviving in the wild. A new study published in the scientific journal Spixiana brought these records into the scientific literature. <Cite refs={[“turn596475search0″,”turn596475search7”]}/>

The discovery is an encouraging development for conservation. However, it also reveals how little scientists know about a critically endangered primate whose remaining habitat faces mounting pressure.

A Primate Missing From Scientific Records Since the 1930s

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The Bangka slow loris (Nycticebus bancanus) was first scientifically described in 1906. The species was subsequently recognized as distinct through modern taxonomic research, but records of the animal remained exceptionally scarce. It was last documented in scientific literature in the 1930s, with 1937 commonly cited as the last record before the recent study. <Cite refs={[“turn596475search1″,”turn596475search4”]}/>

The long gap created a serious problem for conservationists. Without reliable observations, researchers could not confidently establish whether the species had survived, how widely it was distributed, or how many individuals might remain.

The Bangka slow loris was classified as Critically Endangered, with the possibility that it was extinct, on the International Union for Conservation of Nature’s Red List. This classification reflected the lack of recent records and the threats affecting its habitat.

Yet an absence of scientific documentation is not necessarily proof that an animal has disappeared. Some species are difficult to observe because they are nocturnal, live in dense vegetation, or inhabit areas where systematic wildlife surveys are limited.

In this case, the local community continued to encounter the animal even while scientific records remained scarce.

How Local Wildlife Rescuers Helped Rediscover the Species

The breakthrough did not come from a single expedition that suddenly uncovered a hidden population deep in the forest. Instead, it emerged from years of rescue work and reports from people living on Bangka Island.

Between 2015 and 2025, the Alobi Wildlife Rescue Center received reports of slow lorises found in places where residents did not necessarily expect to see wildlife. Some appeared in gardens or along roadsides. Others were found near power lines or in residential areas, where encounters with people could put them at risk.

The rescue center recorded more than 90 individuals identified as Bangka slow lorises. Of these, 86 recovered and were released at seven sites on the island, according to the research summary published by Re. <Cite refs={[“turn596475search0″,”turn596475search6”]}/>

These records helped establish that the species had survived across several parts of Bangka. The reports covered all four regencies of the island as well as Pangkal Pinang, its principal city, suggesting that the animal’s distribution may extend across much of the island. <Cite refs={[“turn596475search0″,”turn596475search8”]}/>

The findings also demonstrate why local knowledge matters in wildlife conservation. Residents can notice animals in their surroundings long before researchers have enough evidence to publish formal scientific records.

For people on Bangka, the slow loris was not a newly discovered animal. What changed was the scientific understanding of its continued survival.

What Makes the Bangka Slow Loris So Unusual?

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At first glance, the Bangka slow loris may look like a small, wide-eyed forest animal. Its large eyes help it navigate in low light, while its slow, deliberate movements suit its nocturnal lifestyle.

But one of its most remarkable characteristics is its venomous defense.

Slow lorises are the only primates known to produce venom. They have specialized glands on the inside of their upper arms. When threatened, a slow loris can bring its mouth into contact with these glands and mix the resulting secretion with saliva. A bite can then deliver the toxic mixture, potentially causing severe pain and swelling. <Cite refs={[“turn596475news23″,”turn596475search6”]}/>

This unusual adaptation distinguishes slow lorises from most other primates, which do not possess a comparable venom system.

The venom is generally understood to serve a defensive function. It can discourage predators and may also make the animals less attractive to potential threats. However, the precise role of venom in the Bangka slow loris’s behavior and ecology remains an area where further research is needed.

Despite its small size and appealing appearance, this animal should never be treated as a harmless pet. Handling a slow loris can stress the animal and expose people to a potentially dangerous bite.

Its distinctive appearance has also made slow lorises vulnerable to the exotic pet trade, adding another challenge to their survival.

Why More Than 90 Rescued Animals Do Not Reveal the Whole Population

The rediscovery is significant, but the number of rescued animals needs to be understood in context.

The more than 90 individuals documented by Alobi represent animals encountered through rescue operations over a decade. They are not a complete census of every slow loris living on Bangka Island.

Some individuals may have been encountered more than once, and many animals could remain undetected in forest fragments or other habitats. Rescue records alone cannot establish the species’ total population, its reproductive success, or whether numbers are increasing or declining.

Researchers still need systematic field surveys to estimate population density and identify the areas where the animals are most likely to survive. Genetic studies could also help establish the level of diversity within the population and clarify its relationship to other slow loris species.

These questions are important because a species can persist across a broad area while still having a very small or fragmented population.

The findings provide evidence that the Bangka slow loris is not extinct. They do not, however, mean that its long-term survival is secure.

Habitat Destruction Poses a Major Threat

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Bangka Island has experienced substantial environmental pressure from human activities. Illegal tin mining, forest clearing for oil palm plantations, expanding settlements, and infrastructure development have reduced and fragmented natural habitats.

For an arboreal primate, the loss of connected tree cover can be especially damaging. Forests provide shelter, food, and routes for moving between different parts of a habitat. When trees disappear or forest fragments become isolated, animals may be forced to cross roads, enter gardens, or move near power lines.

These encounters can result in injuries or leave the animals more vulnerable to capture.

The wildlife rescue records reflect this difficult relationship between people and wildlife. Some slow lorises were found in developed areas rather than undisturbed forest, illustrating how habitat changes can bring animals into closer contact with human activity. <Cite refs={[“turn596475search5″,”turn596475search7”]}/>

The illegal wildlife trade creates an additional danger. Slow lorises are sometimes captured for the exotic pet market, where their large eyes and unusual appearance can make them attractive to buyers. Removing animals from the wild can further weaken populations that may already be under pressure.

Protecting the species therefore requires more than rescuing individual animals. It also requires preserving the natural environments that allow them to survive without human intervention.

How Conservationists Are Working to Protect the Species

The work of Alobi Wildlife Rescue Center has helped turn local observations into valuable scientific evidence. Its efforts include responding to reports, rehabilitating rescued animals, and returning suitable individuals to protected forest areas.

According to Re’s summary of the research, the 86 recovered slow lorises were released at seven locations selected for their remaining forest habitat and some degree of protection. <Cite refs={[“turn596475search0″,”turn596475search2”]}/>

These releases offer a practical contribution to conservation, but their long-term success will need to be assessed through continued monitoring. An animal’s release does not automatically guarantee survival, successful reproduction, or the recovery of the wider population.

Researchers and conservation organizations have identified several priorities for the next phase of work:

• Conduct field surveys to estimate population size and determine where the species survives.
• Carry out genetic research to better understand its diversity and evolutionary history.
• Protect remaining forest fragments and improve habitat connectivity where possible.
• Strengthen enforcement against illegal wildlife capture and trade.
• Continue rescue, rehabilitation, and carefully monitored releases.
• Work with local communities to reduce harmful encounters and improve awareness of the species.

The central challenge is to connect the success of rediscovery with lasting protection on the ground.

A Rediscovery That Offers Hope—and a Warning

The return of the Bangka slow loris to scientific attention is a reminder that wildlife can remain overlooked even when local people continue to encounter it.

The story also highlights the importance of long-term rescue work, community observations, and collaboration between local organizations and researchers. Without those records, scientists might have continued to view the species primarily through the lens of its long absence from published research.

Now, there is renewed evidence that the primate survives across several parts of Bangka Island. That knowledge gives conservationists a stronger foundation for planning surveys, studying its biology, and protecting its habitat.

But rediscovery is only the beginning. The species remains critically endangered, and major questions about its population and future remain unanswered.

The next task is to ensure that the Bangka slow loris does not become genuinely extinct after spending so many decades outside the scientific spotlight.

Its story carries a powerful lesson: sometimes, a species is not gone. It is simply waiting for the world to pay attention—and for the forests it depends on to remain standing.