A Bangka slow loris hangs from a tree on the Indonesian island of Bangka, east of Sumatra, in this undated photograph released on October 20, 2026.
| Photo Credit:
Andre Septian/Alobi Wildlife Rescue Center
The Bangka slow loris is one of
Earth’s most exotic primates, a slow-moving tree dweller that
happens to be venomous. It was listed as critically endangered
and possibly extinct, last scientifically documented in the
1930s, but now has been rediscovered on the tropical Indonesian
island of Bangka.
Scientists revealed in a new study that an animal rescue
organization came across more than 90 Bangka slow loris
individuals in recent years on Bangka, located off the
southeastern coast of Sumatra. Most were returned to the wild.
“The Bangka slow loris is still alive,” said Timon Glaw, a
graduate student in nature conservation and biodiversity
management at the Haus des Meeres Aqua Terra Zoo in Vienna,
Austria, and one of the authors of the study published in the
journal Spixiana.
The rescued animals came from different parts of Bangka,
showing the species has survived in several areas despite
extensive habitat destruction and decades of scientific neglect,
Glaw said. Its habitat has been diminished due to tin mining and
land clearing for oil palm plantations, Glaw said.
“What I find particularly astonishing is that such a
charismatic and distinctive primate has received so little
scientific attention for nearly a century. Its rediscovery also
offers hope that other species feared to be extinct may still
survive in places where scientists have not looked for decades.
After all, Bangka is just about an hour flight from Jakarta, one
of the largest cities in the world,” Glaw said.
The Bangka slow loris, whose scientific name is Nycticebus
bancanus, is a relatively small, nocturnal primate, with
reddish-brown fur, distinctive facial markings and large eyes.
It moves slowly and deliberately in the trees, unlike other
arboreal primates such as apes, monkeys and lemurs that can move
quickly across branches.
In the primate evolutionary lineage, the Bangka slow loris
is more closely related to the lemurs of Madagascar and the
galagos of Africa than to monkeys or apes — or people.
“The last historical scientific records from Bangka
discussed in our study date back to the early 1930s, more
precisely to the period between 1930 and 1932. For decades,
there was no reliable information on whether the species
survived on the island,” Glaw said.
In 2020, the International Union for Conservation of Nature,
the organization that monitors the status of species, deemed the
Bangka slow loris critically endangered and possibly extinct.
The species also was listed as one of the “lost primates” by the
conservation group Re:wild.
A VENOMOUS BITE
Like the world’s other slow loris species, it is venomous —
a rare trait among mammals. Slow lorises produce a secretion
from specialized glands near their elbows, which they mix with
saliva by raising their arms when threatened and then licking
the glands before delivering the venom through a bite.
“The venom can cause severe allergic reactions in humans,
potentially even life-threatening ones. Research on other slow
loris species suggests that the venom is used primarily in
conflicts with other lorises, although it may also serve
defensive functions against predators and parasites,” Glaw said.
Its diet is not well understood, but it likely feeds on
insects, tree gums, nectar and other plant parts like other slow
loris species, Glaw said.
It possesses a toothcomb formed by forward-projecting lower
teeth, used mainly for grooming, gouging of tree bark for gum
and delivering the venom during bites. It also has a specialized
second tongue beneath the main tongue that helps clean the
toothcomb.
Between 2015 and 2025, the Indonesian conservation
organization Alobi Wildlife Rescue Center documented more than
90 Bangka slow lorises from different localities across the
island, Glaw said.
Many were rescued from houses, gardens, plantations or
roads, while others suffered severe injuries, particularly from
electrical wires, with a few dying despite treatment, Glaw said.
Following their recovery, 86 of them were released into suitable
natural habitats, Glaw said.
“The most urgent priority is to protect the remaining
natural forests on Bangka from further destruction, particularly
through tin mining and the expansion of oil palm plantations. We
also need systematic field surveys to determine where the
species still survives and how large its populations are,” Glaw
said.
“Every species is the result of millions of years of
evolution and part of a complex ecological network, and losing
the Bangka slow loris would mean losing something truly
irreplaceable,” Glaw said.
Published on October 21, 2026
