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Wildlife Guide · Indonesia & Malaysia

Slow Loris

Nycticebus spp. (and Xanthonycticebus pygmaeus, the pygmy slow loris, since 2022)

Viral pet videos are fuelling the extinction of the world's only venomous primate.

Threatened (Vulnerable–Critically Endangered)
Slow loris with large round eyes in a rehabilitation enclosure

Image: Source: Wikimedia Commons — “Nycticebus coucang, Sunda slow loris - Kaeng Krachan National Park (25704660113)” by Rushen, CC BY-SA 2.0

In brief

Slow lorises are small nocturnal primates from South and Southeast Asia; every species is threatened with extinction — ranging from Vulnerable to Critically Endangered — largely because of the illegal pet trade, which is fuelled in part by viral social media videos.

By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated

Slow lorises are small, nocturnal primates native to the tropical forests of South and Southeast Asia. They are the only known venomous primates — venom is produced by a gland near the elbow and activated when mixed with saliva. They are also among the most heavily trafficked primates in the world, driven by demand for exotic pets fuelled by viral social media videos. Every slow loris species is threatened with extinction, ranging from Vulnerable to Critically Endangered, and all assessed populations are declining.

9

Species — all threatened, Vulnerable to Critically Endangered

Appendix I

CITES listing — all commercial trade banned since 2007

Pliers

Teeth routinely cut or pulled without anaesthetic before sale

Decreasing

Population trend for every assessed species

Figures sourced from IUCN Red List — Javan slow loris (Nycticebus javanicus), IUCN Red List — search slow loris assessments, CITES — Appendices (Nycticebus listed Appendix I) and other references on this page.

Slow Loris: Quick Facts

Vital statistics and key facts about the Slow Loris
Lifespan Up to ~20 years in human care (pygmy slow loris averages ~17 years); wild lifespan poorly documented
Weight ~265 g (Bornean) to ~2,100 g (Bengal); pygmy slow loris ~120–500 g
Head-body length ~18–38 cm across species (pygmy ~15–25 cm)
Diet Omnivore/exudativore — tree gum and sap, nectar, fruit, insects and small vertebrates
Gestation ~185–197 days (about 6 months)
Young per birth Usually 1; twins common in the pygmy slow loris
Sexual maturity Females ~9 months; males ~18–20 months (pygmy slow loris)
Activity Nocturnal and arboreal; slow, deliberate quadrupedal climbing (no leaping)
Distinction Only venomous primates; brachial-gland secretion activated with saliva
CITES Appendix I (all species, since 2007)

Scientific Classification

Scientific classification of the Slow Loris
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Primates
Family Lorisidae
Genera Nycticebus; Xanthonycticebus (pygmy slow loris, since Nekaris & Nijman, 2022)
Species ~9 slow loris species total (8 Nycticebus + Xanthonycticebus pygmaeus)

Conservation Status

IUCN Status
Varies: Vulnerable to Critically Endangered (per species)
Population
No reliable combined global estimate; species assessed individually and surveyed at low densities
Trend
Decreasing for all assessed species
Assessed
Per species (e.g. Javan slow loris assessed Critically Endangered, listed since 2013)
CITES
Appendix I (all slow lorises, uplisted from Appendix II in 2007)

Only the Javan and Bangka slow lorises are Critically Endangered; others are Endangered (Bengal, Sunda, Sumatran) or Vulnerable (Bornean, Kayan, Philippine).

Did you know?

Slow lorises are the only venomous primates on Earth: they draw a secretion from a gland near the elbow, mix it with saliva, and can deliver a bite toxic enough to cause anaphylactic shock in humans — and mothers even coat their infants in it to ward off predators.

Key Facts: Slow Loris

  • Every slow loris species is threatened with extinction and declining: the Javan and Bangka slow lorises are Critically Endangered, the Bengal, Sunda and Sumatran are Endangered, and the Bornean, Kayan and Philippine are Vulnerable.
  • Before being sold as pets, slow lorises routinely have their teeth cut or pulled out with pliers or clippers — without anaesthetic — to prevent their venomous bite.
  • Pet-trade mortality is severe across capture, transport and captivity; tooth removal causes infection and stress that many animals do not survive.
  • The sight of a "ticklish" slow loris raising its arms in viral videos is actually a fear response — the animal is lifting its arms to access its venom gland.
  • Slow lorises cannot be legally traded internationally — all species were uplisted to CITES Appendix I in 2007 — and possession is illegal in most range and import countries.
  • Rehabilitation is possible but extremely difficult because of their specialist gum-and-insect diet, nocturnal habits, and the trauma and dental mutilation caused by captivity.

Why Social Media Is Driving Extinction

Videos of slow lorises being "tickled" or held as pets have accumulated hundreds of millions of views across YouTube, Instagram, and TikTok. Many viewers are unaware that the animal's raised arms represent a fear response to threat, not enjoyment. The videos create demand — people want one. To meet that demand, poachers take wild animals from the forest at night, using torches to freeze them (their eyes reflect the light via a layer called the tapetum lucidum, and sudden brightness disorients them), then cut or pull their teeth out so they cannot bite. Those that survive reach markets in Indonesia, Vietnam, and Thailand. The trafficking networks running these markets have become sophisticated at evading enforcement, and the viral cycle continues.

The Venom No One Talks About

Slow lorises are unique among primates in producing venom. The venom is formed by combining a secretion from a brachial gland near the elbow with saliva. It is used both for defence and in mother-infant interactions, where mothers coat their young to deter predators. The venom of some species can cause anaphylactic shock in humans — a documented case followed the bite of a wild Kayan slow loris. This is why pet slow lorises have their teeth removed — and why the operation, performed without anaesthetic by traders, is so often fatal. A slow loris without teeth is also unable to feed naturally, further compromising its welfare in captivity.

What Happens at a Rescue Centre?

Slow lorises confiscated from markets or surrendered by owners arrive with multiple serious problems: dental mutilation, malnutrition, metabolic bone disease from an inadequate diet, severe stress, and sometimes injuries from confinement. Triage involves dental assessment, rehydration, and a carefully controlled reintroduction to natural food — primarily tree gum and sap, nectar, and invertebrates, the exudativore diet they are built for. Animals that cannot be released require lifetime sanctuary care in appropriately sized nocturnal enclosures. Those that recover sufficiently undergo pre-release assessment before soft release into protected forest.

Taxonomy: One Genus Becomes Two

Slow lorises are strepsirrhine primates — relatives of lemurs and bushbabies, not monkeys. Most were long grouped in the single genus Nycticebus. In 2022 the pygmy slow loris was moved into its own genus, Xanthonycticebus pygmaeus, on the basis of genetic and morphological differences. Counting it, most current sources recognise nine slow loris species in total: eight in Nycticebus plus the pygmy slow loris. All belong to the family Lorisidae and share the same slow, deliberate, non-leaping climbing style and round, forward-facing eyes adapted for night vision.

Key slow loris species: range and IUCN status

SpeciesScientific nameMain rangeIUCN status
Javan slow lorisNycticebus javanicusJava (Indonesia)Critically Endangered
Bangka slow lorisNycticebus bancanusBangka & Borneo (Indonesia)Critically Endangered
Bengal slow lorisNycticebus bengalensisIndia, Bangladesh, mainland SE Asia, S ChinaEndangered
Sunda slow lorisNycticebus coucangSumatra, Malay PeninsulaEndangered
Bornean slow lorisNycticebus borneanusBorneoVulnerable
Philippine slow lorisNycticebus menagensisBorneo, PhilippinesVulnerable
Pygmy slow lorisXanthonycticebus pygmaeusVietnam, Laos, Cambodia, S ChinaEndangered

What WARN Does

WARN focuses current slow loris rescue funding on Indonesia and Malaysia, while keeping Vietnam, Thailand and Cambodia context live for education about the wider viral pet-trade crisis.

A rescued slow loris needs months of round-the-clock care — a controlled return to its natural gum-and-insect diet, dental treatment, and a quiet nocturnal enclosure — before it can even be assessed for release. Your gift helps WARN's partners in Indonesia and Malaysia fund that recovery, one loris at a time.

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Slow Loris: Frequently Asked Questions

Are slow lorises venomous?
Yes — slow lorises are the only known venomous primates. They produce venom by combining a secretion from a gland near their elbow with saliva. The venom is used for defence and can cause anaphylactic shock in humans, as documented after the bite of a wild Kayan slow loris. This is why slow lorises sold as pets have their teeth removed — an operation performed without anaesthetic that many animals do not survive.

Why do slow lorises raise their arms?
When a slow loris raises its arms, it is not "enjoying being tickled" — it is accessing its venom gland in preparation for a defensive bite. The behaviour shown in viral videos is a fear response to being handled. The animal's eyes are also often called "cute" when in fact they are wide open because they are being exposed to bright light, which is painful and disorienting for a nocturnal animal.

Can you keep a slow loris as a pet?
No. All slow loris species were uplisted to CITES Appendix I in 2007, making commercial international trade illegal. National legislation in range countries and in most import countries also prohibits possession. Any slow loris offered for sale has almost certainly been illegally taken from the wild.

Are all slow loris species critically endangered?
No. Of the recognised slow lorises, only the Javan (Nycticebus javanicus) and Bangka (N. bancanus) are Critically Endangered. The Bengal, Sunda and Sumatran are Endangered, while the Bornean, Kayan and Philippine slow lorises are Vulnerable. Every assessed species is declining, so all are threatened with extinction even though they are not in a single category.

What do slow lorises eat?
They are omnivores with a strong reliance on tree gum and sap, which makes them exudativores, supplemented by nectar, fruit, insects and the occasional small vertebrate. This specialist diet is one reason they are so difficult to feed correctly in captivity, and why rescued animals often arrive with metabolic bone disease.

Where do slow loris live?
Slow Loris live in Indonesia, Malaysia, Vietnam. Slow lorises are small nocturnal primates from South and Southeast Asia; every species is threatened with extinction — ranging from Vulnerable to Critically Endangered — largely because of the illegal pet trade, which is fuelled in part by viral social media videos.

Are slow loris dangerous?
They are the only known venomous primates — venom is produced by a gland near the elbow and activated when mixed with saliva. They are nocturnal and arboreal; slow, deliberate quadrupedal climbing (no leaping). Give wild slow loris space; do not corner or handle them.

How long do slow loris live?
Slow Loris typically live Up to ~20 years in human care (pygmy slow loris averages ~17 years); wild lifespan poorly documented. Slow lorises are small nocturnal primates from South and Southeast Asia; every species is threatened with extinction — ranging from Vulnerable to Critically Endangered — largely because of the illegal pet trade, which is fuelled in part by viral social media videos. Wild and captive figures can differ; use the sources listed on the guide for the underlying studies.

How big is a slow loris?
A Slow Loris is about Up to ~20 years in human care (pygmy slow loris averages ~17 years); wild lifespan poorly documented. Slow lorises are small nocturnal primates from South and Southeast Asia; every species is threatened with extinction — ranging from Vulnerable to Critically Endangered — largely because of the illegal pet trade, which is fuelled in part by viral social media videos.

Sources & References

Population figures, conservation status and biological facts on this page are drawn from authoritative scientific and intergovernmental sources.

Related Rescue Guides

Focused answers for people searching how slow loris rescue works in high-need regions.

Southeast Asia · Exotic pet trade

Slow Loris Pet Trade Rescue

Slow loris pet trade rescue is difficult because trafficked lorises often arrive with clipped teeth, stress injuries and specialist dietary needs after being taken from the wild for viral exotic pet demand.

Thailand · Wildlife tourism welfare

Ethical Wildlife Tourism in Thailand

Ethical wildlife tourism in Thailand means choosing genuine non-contact sanctuaries and avoiding riding, bathing, selfies, performances, cub handling and any venue that breeds or trades animals for visitors.

Malaysia · Transit routes

Malaysia Wildlife Trafficking

Malaysia wildlife trafficking matters because the country sits on key regional routes for pangolins, birds, reptiles and big-cat parts, making customs detection and live-animal rescue capacity especially important.

Slow loris · Pet trade injury

Rescued Slow Loris Teeth Removed

Slow loris teeth are often cut or pulled by traders to prevent biting; rescued lorises with dental damage need urgent veterinary care and may be unable to return to the wild.

Terms used on this page

Plain-English definitions, from our wildlife and conservation glossary.

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