L
Species Profile

Loris

Lorisidae

Quiet climbers of the night canopy
Conservationist/Shutterstock.com
Most Vicious Animals

At a Glance

Family Overview This page covers the Loris family as a group. Stats below are general traits shared across the family.
Also Known As Slow loris, Slender loris, Potto, Angwantibo, Golden potto
Diet Omnivore
Activity Nocturnal+
Lifespan 15 years
Weight 2.1 lbs
Status Not Evaluated
Did You Know?

Size range across Lorisidae: about 17-40 cm head-body length; most have only a tiny tail (often just a few cm or less).

Scientific Classification

Family Overview "Loris" is not a single species but represents an entire family containing multiple species.

Lorises (in the broad sense of lorisid primates) are small, nocturnal, arboreal strepsirrhine primates characterized by strong grasping hands/feet, large eyes adapted to night vision, and slow, careful locomotion in many species.

Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Primates
Family
Lorisidae

Distinguishing Features

  • Nocturnal, arboreal primates with strong grasping hands/feet
  • Large forward-facing eyes; reduced snout typical of many primates
  • Slow, deliberate climbing in many species (notably slow lorises)
  • Strepsirrhine traits (e.g., grooming claw and toothcomb)

Did You Know?

Size range across Lorisidae: about 17-40 cm head-body length; most have only a tiny tail (often just a few cm or less).

Weight range spans roughly ~0.1-2.1 kg, from the smallest slender lorises to the largest slow lorises and some pottos.

Lifespan ranges about ~10-30 years across species (shorter in the wild; some reach 20+ and even ~30 in captivity).

All lorisids are strepsirrhine primates with a toothcomb-specialized lower front teeth used for grooming and, in many, to help harvest tree gums.

Not all "lorises" move equally slowly: slow lorises and pottos are famously deliberate, while slender lorises can be noticeably quicker and more agile.

Some lorisids rely heavily on plant exudates (tree gums/nectar), while others can be more insect- and small-vertebrate-focused-diet varies by habitat and genus.

Slow lorises (Nycticebus) are among the very few venomous mammals: they can deliver a toxic bite using a brachial (arm) gland secretion mixed with saliva.

Unique Adaptations

  • Exceptional grasping ability supported by specialized blood-vessel networks (retia mirabilia) in the limbs that help sustain a strong grip with reduced fatigue-useful for long, careful climbs.
  • Large forward-facing eyes and a reflective layer (tapetum lucidum) that enhance low-light vision for nocturnal hunting and navigation.
  • Toothcomb (a strepsirrhine hallmark) for grooming and, in several lorisids, for scraping gums/exudates-an important, reliable food source.
  • Low, cautious locomotion in many species reduces detection and can aid stealth predation on insects; combined with strong hands/feet for secure arboreal movement.
  • Venom system in slow lorises: a brachial gland secretion combined with saliva can make bites medically significant and may also be used in intraspecific competition.
  • Cryptic coloration and quiet, deliberate movement suited to dense forest understories and canopy shadows.
  • In pottos and angwantibos, robust neck/shoulder morphology (including protective bony projections in pottos) supports distinctive defensive postures.

Interesting Behaviors

  • Nocturnal foraging in the mid- to upper canopy, using stealth and slow, careful limb placement (especially slow lorises and pottos); slender lorises often travel faster and more directly.
  • Powerful, sustained grasping and "freeze" responses: individuals may remain motionless for long periods to avoid detection by predators.
  • Dietary flexibility across the family: combinations of insects, tree gums/exudates, nectar, fruit, and occasional small vertebrates-proportions vary by species and season.
  • Scent-marking and chemical communication are common; many species maintain overlapping home ranges and use scent to signal status or reproductive state.
  • Social systems vary: from largely solitary foraging with loose associations, to pair-living or small family groupings in some populations; vocal calls help coordinate at night.
  • Infant care strategies differ among genera, including "parking" infants on branches while the mother forages in some species, versus more frequent carrying in others.
  • Defensive behaviors include quiet withdrawal, biting, and in pottos, presenting a spiny neck/shoulder region; in slow lorises, toxin-assisted bites can be a serious deterrent.

Cultural Significance

Slow and slender lorises in South and Southeast Asia are night animals—feared or wanted—and harmed by the pet trade, traditional medicine, and online demand. In West and Central Africa, pottos and angwantibos are part of local knowledge and may be hunted, tying their survival to forest care and local jobs.

Myths & Legends

In parts of Sri Lanka and South Asia, slender lorises have been associated in local belief with omens and nocturnal supernatural themes; such associations have historically influenced how people treat (or avoid) them.

In segments of Southeast Asia, slow lorises have been tied to folk practices that attribute special properties to their body parts-beliefs that have contributed to their capture and trade.

In regions of Central and West Africa, pottos and other nocturnal forest animals are sometimes woven into cautionary tales about the dangers and mysteries of the night forest, reflecting their elusive, secretive habits.

Conservation Status

NE Not Evaluated (family-level). Individual Lorisidae species span LC-CR (with some DD); overall conservation outlook is broadly declining across much of the range.

Has not yet been evaluated against the criteria.

Population Decreasing

Protected Under

  • CITES: Nycticebus (slow lorises) listed in Appendix I; other Lorisidae generally in Appendix II (international trade regulated).
  • National protections vary by range country (e.g., wildlife protection laws in India, Sri Lanka, Indonesia, Malaysia, Thailand, Vietnam; and relevant wildlife legislation across Central/West African range states for pottos/angwantibos).
  • Family-level diversity note (not a law): Lorisidae are small nocturnal arboreal primates; adult body mass is roughly ~0.2-2.1 kg and head-body length ~17-40 cm; lifespan often ~10-25+ years (longer in captivity). Ecology varies from very slow, cautious climbing to more active foraging; diets mix insects, gums/exudates, and fruit, with variation among genera and habitats.

You might be looking for:

Slow lorises

55%

Nycticebus

Nocturnal Asian lorises with a slow, deliberate climbing style; notable for a venomous bite and large forward-facing eyes.

Slender lorises

25%

Loris (genus)

Small, very slender Asian lorises (India/Sri Lanka), nocturnal and highly arboreal with long limbs and quick, silent movements compared to slow lorises.

Pottos

12%

Perodicticus (genus)

African nocturnal primates in the same family; stockier than lorises and often grouped with them under Lorisidae in taxonomy.

Angwantibos

8%

Arctocebus (genus)

Small African lorisids related to pottos; slow-moving, nocturnal, and arboreal.

Life Cycle

Birth 1 infant
Lifespan 15 years

Lifespan

In the Wild
10–20 years
In Captivity
12–30 years

Reproduction

Mating System Polygynandry
Social Structure Solitary
Breeding Pattern Transient
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Across Lorisidae, adults are typically solitary foragers with overlapping home ranges; mating occurs opportunistically when ranges overlap. Both sexes may mate with multiple partners, with limited pair-bonding in some populations and no consistent cooperative care.

Behavior & Ecology

Social Family group Group: 2
Activity Nocturnal, Crepuscular
Diet Omnivore Tree gums/exudates and arthropods (importance varies across genera: many slow lorises are strongly gummivorous; pottos/angwantibos tend to be more insect-focused).

Temperament

Generally cryptic and cautious; slow, deliberate arboreal movement reduces detection by predators.
Often tolerant at close range but avoidant; aggression is typically limited to brief disputes.
Territoriality varies: many scent-mark core areas, with broader home-range overlap between sexes.
Anti-predator strategies vary across genera: freezing, concealment, and occasional defensive biting.
Dietary ecology is broad: insects, gums, nectar, and fruit; proportions vary by habitat and species.
Body size range across lorises: roughly ~80 g to ~2.1 kg; head-body length ~15-40 cm.
Lifespan range: commonly ~10-20+ years in the wild; up to ~25-30 years in captivity.

Communication

whistles
chirps
clicks
grunts
growls
screeches
infant squeaks
alarm calls
scent marking with urine and glandular secretions
allogrooming and tactile contact during reunions
visual signals at close range Posture, facial orientation
mother-infant contact calls and following
rubbing and branch marking along travel routes

Habitat

Biomes:
Tropical Rainforest Tropical Dry Forest Savanna Wetland
Terrain:
Plains Hilly Valley Riverine Coastal Island
Elevation: Up to 7874 ft

Ecological Role

Nocturnal arboreal omnivores that act primarily as insect/arthropod predators and secondary plant-resource consumers (gums, nectar, fruit), with diet composition varying among genera and habitats.

suppression of nocturnal insect populations (predation on herbivorous arthropods) pollination contributions in nectar-feeding bouts (where flower visitation is frequent) seed dispersal in taxa/periods with higher fruit intake trophic linkage between canopy arthropods and higher predators (as both predator and prey in forest food webs)

Diet Details

Main Prey:
Insects Other arthropods Snails and other small invertebrates Small vertebrates Bird eggs and nestlings
Other Foods:
Tree gums and other exudates Nectar Flowers and buds Fruits

Human Interaction

Domestication Status

Wild

Lorisidae are wild primates with no domesticated forms. People capture them for food, traditional medicine, pets and tourist photos, research, and growing conservation or ecotourism. They are small (15–40 cm, 0.1–2 kg), nocturnal, arboreal, omnivorous, and live about 10–25 years. Many face habitat loss and illegal trade; CITES and national rules often ban private ownership.

Danger Level

Moderate
  • Bites and deep puncture wounds (all lorisids can bite when stressed or handled)
  • Allergic reactions/anaphylaxis risk from venom in some lorisids (notably slow lorises; severity varies by individual and exposure)
  • Zoonotic disease risk from close contact and illegal trade handling (e.g., bacterial infections from bites; broader zoonotic exposure risk typical of primates)
  • Psychological/behavioral stress responses leading to defensive aggression, especially under capture/handling

As a Pet

Not Suitable as Pet

Legality: Mostly illegal or tightly limited: Lorisidae are protected where they live and listed by CITES, so international trade is controlled. Private ownership usually needs special permits or is banned; many pets come from illegal trade.

Care Level: Expert Only

Purchase Cost: Up to $15,000
Lifetime Cost: $20,000 - $150,000

Economic Value

Uses:
Ecotourism and wildlife viewing Conservation funding and education Scientific research (behavior, ecology, sensory biology, conservation medicine) Illegal wildlife trade (pet market, live capture) Traditional medicine/folklore use in some regions
Products:
  • Tourism experiences (guided nocturnal walks where regulated)
  • Educational programming (zoos/rescues, where legal and ethical)
  • Research data/biological samples collected under permits
  • Illicit live-animal sales and photo-prop handling (harmful to animals)
  • Traditional remedies (regionally variable; often illegal or discouraged)

Relationships

Related Species 4

Galagos
Galagos Galagidae Shared Order
Mouse lemurs Microcebus Shared Order
True lemurs Lemuridae Shared Order
Aye-aye
Aye-aye Daubentonia madagascariensis Shared Order

Ecological Equivalents 5

Animals that fill a similar ecological role in their ecosystem

Tarsier
Tarsier Tarsiidae Nocturnal, arboreal primates that hunt animal prey at night; they overlap in forest strata and sensory adaptations (large eyes), although locomotion differs—tarsiers are more specialized for leaping and are highly predatory.
Night monkeys Aotus Nocturnal, arboreal primates of the Neotropics; ecological analogues in activity pattern and canopy use, though unrelated (haplorhines) and generally faster-moving.
Kinkajou
Kinkajou Potos flavus Nocturnal, arboreal mammal that uses fruit and nectar, sharing canopy niche elements (night foraging, grasping and climbing); taxonomically a procyonid and typically larger.
Brushtail possums Phalangeridae Nocturnal, arboreal mammals with omnivorous diets and slow-to-moderate climbing abilities; ecological parallels in night-time canopy foraging despite belonging to a different lineage and occurring on a different continent.
Sloths Folivora Classic example of slow, deliberate arboreal locomotion and cryptic behavior; ecological similarity is primarily in locomotor and anti-predator strategy, though diet and biogeography differ strongly.

Types of Loris

14

Explore 14 recognized types of loris

Bengal slow loris Nycticebus bengalensis
Sunda slow loris Nycticebus coucang
Javan slow loris Nycticebus javanicus
Pygmy slow loris Nycticebus pygmaeus
Bornean slow loris Nycticebus borneanus
Kayan River slow loris Nycticebus kayan
Menage's slow loris Nycticebus menagensis
Gray slender loris Loris lydekkerianus
Red slender loris Loris tardigradus
Potto
Potto Perodicticus potto
Central African potto Perodicticus edwardsi
East African potto Perodicticus ibeanus
Calabar angwantibo Arctocebus calabarensis
Golden angwantibo Arctocebus aureus

Like all lorises, slow loris has a cute wide-eyed look, but it also has a venomous sting that can rot human flesh. 

CONSERVATION STATUS

The International Union for Conservation of Nature (IUCN) considers all loris species (except the gray slender loris) threatened. The conservation status of relatively common lorises is as follows:

  • Loris lydekkerianus (Gray slender loris) — Near Threatened 
  • Nycticebus coucang (Slow loris), Nycticebus bengalensis (Bengal slow loris), Loris tardigradus (Red slender loris), and Xanthonycticebus pygmaeus (Pygmy slow loris) — Endangered
  • Nycetibus menagensis (Phillipine slow loris) — Vulnerable
  • Nycticebus bancanus (Bangka slow loris) — Critically Endangered

Summary

Lorises are arboreal and nocturnal creatures with soft gray fur and prominent eyes encircled by dark patches. This group of small primates inhabit the Southern Asia area. There are ten different species of lorises which researchers divide into 3 genera. Lorises are adept at moving through trees. They often hang by the trees with their feet, freeing their hands to grasp food from the branches. The Javan slow loris found on the Indonesian island of Java is one of the only handful of venomous mammals. It has advanced specialized glands under its armpits that produce a toxic venom when mixed with saliva and deliver what is called a necrotic bite. The bite causes flesh to rot.

Loris Facts 

  • The eyes of a loris are like binoculars. They have excellent vision coupled with a special reflective layer across the outside that makes them see clearly at night.
  • Lorises sleep during the day and hunt at night.
  • Their lifespan runs between 15 and 20 years.
  • The loris walks on all four legs.
  • Despite their fearsome reputation, not all species of lorises are venomous. Only slow lorises can secrete venom, and the venom is not toxic in all species. 

Scientific Name

Loris refers to any of the 10 species of short-tailed or tailless primates in the subfamily Lorisinae. They are native to the forests of south and southeast Asia. Their common name is from the old Dutch word “loeris” which means “clown.” Lorises belong to the Lorisidae family, in which there are more than 16 species divided into 5 genera. Lorises are close relatives of the Lemurs (family Lemuroidea). Some of the most notable genera in the subfamily Lorisinae include: 

  • Loris lydekkerianus — Gray slender loris 
  • Loris tardigradus — Red slender loris 
  • Xanthonycticebus — Pygmy slow loris 
  • Nycticebus — Slow loris 

Loris — Appearance & Behavior 

Slowest Animals: Slow Loris

A Slow loris hanging on a tree. The movement of a slow loris is snakelike. This is because a slow loris has more spinal vertebra than other primates.

While there are many different species of lorises, they’re all quite similar in shape and size. They have round faces, large eyes, and colored patches of fur around their eyes. As opposed to monkeys and many other primates, they do not have long tails but short stubs that serve as tails. They have short legs in comparison to other primates. All have strong hands and toes. They move with slow and deliberate hand-over-hand movements. 

Lorises vary in size from one genus to the other. Slender lorises, for instance, are about 8–10 inches long and may weigh as much as 0.55 pounds. The slow lorises are more robust. They’re typically about 11–15 inches long. They may weigh as much as 2 pounds, with the Bengal slow loris weighing up to 4 pounds. 

Behavior 

If alarmed, lorises can move quickly, but they hardly jump or leap. Their vampire-looking teeth are filled with grooves and are very sharp. Lorises know how to use the sharpness of their teeth to their advantage. They bite extremely hard, whether biting into flesh, the bark of a tree, or even a bone.

While their social behavior ranges from species to species, all lorises are arboreal and spend most of their time in trees. Some species live in small groups but forage alone. Those that live together generally like to congregate during the day when they sleep. All species are nocturnal. Lorises do not like to be separated from their kin. In the wild, they live together in family units, where parents and older ones care for the young ones who stay in the care of their parents for at most three years.

One defensive feature of slender and slow lorises is to freeze when they’re in danger until the danger passes. If this doesn’t work, they will stare brazenly at the attacker and growl while oozing a foul, offensive stench from scent glands under their arms. Before going off to forage, mothers park their babies in trees, lick their brachial glands, and then groom their young so that the venom is transferred to the fur of their infants. This is a deterrent against predators like leopards and bears.

Loris — Habitat 

Each loris species has different preferences when it comes to choosing a habitat. However, tropical rainforests are a popular favorite due to the abundance of trees on which they live. Some species prefer areas with less rainfall. Lorises can also be found in agricultural regions like plantations. Slender lorises have been found in India and on the Island nation of Sri Lanka at 15 degrees latitude.

Lorises are well suited to exploring and exploiting different types of habitats. They are often found in low swampy areas, humid tropical rainforests, and drier areas like fairly deciduous forests. The Sunda slow loris inhabits Peninsular Malaysia and the Indonesian island of Sumatra. The Javan loris is limited to the Indonesian island of Java. During cold nights, pygmy slow lorises that inhabit Vietnam, Eastern Cambodia, and Yunnan, China, are capable of entering a state of inactivity known as torpor. In this state, they reduce metabolism and body temperature for days.

Loris — Threats and Predators

A loris is a predator itself, feeding on insects, small birds, and reptiles. However, their diet is more accurately described as omnivores since they eat eggs, fruits, nectar, gums, and vegetation. Some species are known to be venomous. This group of lorises uses their venom mostly for defense and internal fights over territory or mates. 

Humans are the biggest threat to the population of lorises. Even though it is illegal to capture, sell, or own a loris in all the countries where their population is prominent, they are still caught for their use in traditional Asian medicine and the pet trade. The trade of lorises involves pulling their teeth and subjecting them to critical situations that are cruel, unfair, and in violation of animal welfare. Many of them die while being transported. Besides humans, snakes, hawk-eagles, orangutans, cats, and sun bears are also major predators of the lorises. 

Loris — Reproduction, Babies, and Lifespan 

Breeding, gestation, and infant care range from species to species. Most species have a gestation period that is about six months long, and then they give birth to about one or two babies. A young female loris cannot breed until it is about two years old. For a slender loris, the reproductive behavior is quite different. 

The slender loris breeds all year round in captivity. Mating seasons find the female in estrus for 29-40 days. During mating, females tend to hang on a branch and support the male’s weight along with their own. Gestation ranges from 166 to 169 days for the slender loris. They have a higher percentage of twin births compared to other members of the subfamily.

Newborns are usually pink and furless at the time of their birth, and they cling to their mother’s fur until their infancy fades away. At 10 and 18 months, they reach sexual maturity, but this duration is much slower in males. Their lives span a total of 15 or even 25 years.

Loris — Population

Over the course of the last century, the population of the lorises has been on a steady decline, with as much as a 50% fall in population. Poaching for the exotic pet trade is among the main factors responsible for their sharp decline. Despite government protections guarding lorises, their population continues to drop because wildlife protection laws are weakly enforced locally. The highland slender loris has less than 2,500 individuals surviving across South Western and Central Sri Lanka. Their conservation status is critically endangered. Most of the other species are endangered or threatened. The gray slender loris is near threatened.

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Sources

  1. Britannica / Accessed October 10, 2022
  2. New England Primate Conservancy / Accessed October 10, 2022
  3. Science Direct / Primate Anatomy (Third Edition) / Friderun Ankel-Simons / Accessed October 10, 2022
  4. Active Wild / Accessed October 10, 2022
Abdulmumin Akinde

About the Author

Abdulmumin Akinde

Abdulmumin is a pharmacist and a top-rated content writer who can pretty much write on anything that can be researched on the internet. However, he particularly enjoys writing about animals, nature, and health. He loves animals, especially horses, and would love to have one someday.
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Loris FAQs (Frequently Asked Questions)

Several countries now have laws against keeping lorises as pets, so it is hard to keep them legally. Beyond the legal complexities, some species of lorises have venoms, making it unsafe to keep them around.