Wildlife Guide · Central America & South America

Monkey

Infraorder Simiiformes — ~260+ species in families Cebidae, Callitrichidae, Cercopithecidae and others

Tailed primates of forest, savanna and city — intelligent, social and overwhelmingly wild.

Varies by species (Least Concern to Critically Endangered)

Two Japanese macaques (snow monkeys, Macaca fuscata) resting in a steaming hot spring in winter, snow dusting their thick fur.

Image: Photo: nomao saeki saekinomao / Wikimedia Commons (CC0)

In brief

Monkeys are tailed simian primates of the Americas, Africa and Asia — roughly 260+ species with forward-facing eyes, grasping hands and complex social groups. They are distinct from tailless apes; status ranges from Least Concern to Critically Endangered, and most species are protected from international trade.

By the WARN Research & Conservation TeamChecked against IUCN Red List & CITES sourcesLast updated June 2026

A monkey is a primate in the infraorder Simiiformes — the "simians" — distinguished from prosimians such as lemurs and from tailless apes such as gorillas and chimpanzees. Scientists recognise roughly 260 to 280 monkey species split into New World monkeys of the Americas and Old World monkeys of Africa and Asia. Monkeys range from thumb-sized marmosets to large baboons and mandrills. They share forward-facing eyes, grasping hands and feet, complex social lives and often long childhoods. Conservation status varies sharply: some adaptable species remain common, while specialists such as golden lion tamarins and proboscis monkeys are Endangered. Most monkeys are protected under CITES, and private keeping is restricted in many countries.

260+

Recognised monkey species worldwide

Major groups: New World & Old World

CITES

Most species regulated in international trade

Varies

IUCN status from Least Concern to Critically Endangered

Figures sourced from IUCN Red List — primate assessments, CITES — Checklist of CITES Species, Smithsonian National Zoo — primate facts .

Monkey: Quick Facts

Vital statistics and key facts about the Monkey
Common name	Monkey (many species)
Groups	New World & Old World monkeys
Tail	Present in almost all monkeys; absent in apes
Diet	Mostly frugivorous or omnivorous; varies by species
Trade	Most species CITES Appendix I or II
Pet suitability	Poor — specialist wild animals

Scientific Classification

Scientific classification of the Monkey
Kingdom	Animalia
Phylum	Chordata
Class	Mammalia
Order	Primates
Suborder	Haplorhini
Infraorder	Simiiformes (simians)

Conservation Status

IUCN Status: No single IUCN category applies. Many widespread species are Least Concern; numerous forest specialists are Endangered or Critically Endangered due to habitat loss, hunting and the pet trade.
Population: Varies by species — from abundant to fewer than 1,000 mature individuals
Trend: Decreasing for many forest specialists; stable or increasing locally for some adaptable species
Assessed: Varies by species (IUCN Red List ongoing)
CITES: Most monkey species on CITES Appendix I or II

Great apes are assessed separately; see WARN guides for chimpanzee, gorilla and orangutan.

Key Facts: Monkey

Monkeys have tails; apes (gorillas, chimpanzees, orangutans, gibbons) do not — a quick way to tell them apart.
New World monkeys live in Central and South America; Old World monkeys live in Africa and Asia.
Monkeys are highly social, often living in troops with hierarchies, grooming and learned behaviour.
The golden snub-nosed monkey of China lives in bands of up to 200 — among the largest primate societies.
Most monkeys are poor pets — they need large groups, specialist diets and decades of expert care.
Habitat loss, bushmeat hunting and the illegal pet trade are the main threats across regions.
Great apes are covered in separate WARN guides; this page focuses on monkeys and their species.

What is a monkey — and how is it different from an ape?

Monkeys belong to the simian primates but are not apes. The easiest field distinction is the tail: almost all monkeys have one, while apes — gorillas, chimpanzees, bonobos, orangutans and gibbons — do not. Monkeys also tend to have narrower chests and, in many species, run along branches rather than swing beneath them like apes. Taxonomically, monkeys split into New World monkeys (flat noses, often prehensile tails, native to the Americas) and Old World monkeys (downward-facing nostrils, non-prehensile tails in most species, native to Africa and Asia). Marmosets and tamarins are small New World specialists; macaques and baboons are widespread Old World groups. Understanding this split helps explain why conservation and welfare issues differ between regions.

Behaviour, intelligence and society

Monkeys are among the most behaviourally flexible non-human animals. Many species use tools, share food according to social rules, and transmit local traditions — different troops using different techniques to open nuts or extract insects. Group size ranges from pair-bonded marmosets to baboon troops of dozens or, in some squirrel monkeys, more than a hundred individuals. Communication combines calls, facial expressions and gestures. Mothers carry and nurse infants for months or years, and youngsters learn foraging routes and social rank through observation. That complexity is why monkeys suffer so severely in the pet trade: a single animal in a human home cannot replicate the diet, space or social stimulation of a wild troop.

Threats and conservation

No single IUCN label covers all monkeys. Generalist species such as the rhesus macaque remain Least Concern across a huge range, while specialists — golden lion tamarins, proboscis monkeys, several spider monkeys — are Endangered or Critically Endangered. Deforestation for agriculture, logging and urban sprawl removes the continuous forest many species need. Bushmeat hunting and snares kill monkeys for food and traditional medicine. The illegal pet and entertainment trades still remove infants from mothers, with high mortality in transit. CITES lists most monkey species on Appendix I or II, restricting international commercial trade. Protecting connected habitat, enforcing anti-trafficking law and reducing demand for monkey selfies and pets are the most effective levers.

Monkeys and people

In some regions monkeys live alongside people — rhesus macaques at Indian temples, vervets on African farms, capuchins at forest edges. That proximity creates conflict when crops are raided or tourists feed troops, leading to bites, disease risk and retaliatory killing. Feeding wild monkeys is discouraged by wildlife authorities because it increases aggression and spreads zoonotic disease. Ethical tourism keeps distance and supports habitats rather than direct contact. For WARN's audience, the practical message is clear: admire monkeys in the wild or in accredited sanctuaries, support habitat protection in range countries, and never treat a monkey as a substitute for a domestic pet.

Explore monkey species on WARN

This hub introduces monkeys as a group — but most readers search for a particular species. WARN publishes a twenty-species monkey library on this page covering capuchin, rhesus macaque, golden snub-nosed monkey, proboscis monkey and mandrill, plus the olive baboon, Hanuman langur, Barbary macaque, emperor tamarin, black-and-white colobus, pygmy marmoset, gelada and long-tailed macaque. Flagship guides also cover golden snub-nosed monkey, golden lion tamarin, proboscis monkey and baboon at species level. Great apes — chimpanzee, gorilla, orangutan — have separate WARN pages. All wild primates are CITES-regulated; supporting habitat protection and anti-trafficking work helps every species from Atlantic Forest tamarins to Chinese montane bands.

New World vs Old World monkeys

Feature	New World monkeys	Old World monkeys
Region	Central & South America	Africa & Asia
Families	Cebidae, Callitrichidae & others	Cercopithecidae
Nose	Flat, wide, side-facing nostrils	Narrow, downward-facing nostrils
Tail	Often long; sometimes prehensile (grasping)	Never prehensile; some have short tails
Examples	Capuchin, squirrel monkey, marmoset, tamarin	Macaque, baboon, langur, colobus, gelada
Typical habitat	Mostly tree-dwelling forest species	Forest, savanna, mountains and cities

Monkey Species Guide

From the Capuchin, Rhesus Macaque and Mandrill to the Olive Baboon, Hanuman Langur, Barbary Macaque, Emperor Tamarin, Pygmy Marmoset and Gelada — explore 20 of the world's most searched monkey species with range, behaviour, conservation status and why wild primates belong in the wild.

Capuchin Monkey

Central & South America

Curious, dexterous, social

Rhesus Macaque

South, Central & Southeast Asia

Bold, adaptable, hierarchical

Squirrel Monkey

Central & South America

Active, social, vocal

Japanese Macaque

Japan (Honshu and southern islands)

Social, hardy, intelligent

Common Marmoset

North-eastern Brazil

Active, vocal, family-oriented

Golden Snub-Nosed Monkey

Central China (Sichuan, Gansu, Shaanxi, Hubei)

Cold-hardy, highly social

Spider Monkey

Southern Mexico to Brazil (Neotropical forests)

Acrobatic, frugivorous, far-ranging

Howler Monkey

Central & South America

Loud, leaf-eating, slow-moving

Golden Lion Tamarin

Brazil (Atlantic Forest of Rio de Janeiro)

Striking, social, cooperatively breeding

Vervet Monkey

Eastern & southern Africa

Alert, adaptable, highly vocal

Proboscis Monkey

Borneo (coastal & riverine forest)

Swamp-forest specialist, strong swimmer

Mandrill

West-central Africa (Cameroon, Gabon, Congo, Eq. Guinea)

Colourful, powerful, highly social

Olive Baboon

Equatorial Africa (savanna belt)

Bold, terrestrial, highly social

Hanuman Langur

Indian subcontinent

Agile, leaf-eating, semi-terrestrial

Barbary Macaque

Morocco, Algeria & Gibraltar

Social, hardy, cold-tolerant

Emperor Tamarin

Western Amazon (Peru, Bolivia, Brazil)

Active, vocal, cooperative

Black-and-White Colobus

Equatorial Africa

Arboreal, leaf-eating, graceful

Pygmy Marmoset

Western Amazon basin

Active, secretive, gum-feeding

Gelada

Ethiopian highlands

Grass-grazing, highly social, terrestrial

Long-tailed Macaque

Southeast Asia

Adaptable, intelligent, water-loving

What WARN Does

WARN funds orangutan, slow loris and broader anti-trafficking work in partner countries where primate habitat and welfare overlap our mission. This monkey guide is free public education — helping searchers understand species, threats and why wild primates belong in the wild.

If this guide helps you understand why wild monkeys belong in the forest, a gift to WARN supports habitat protection and anti-trafficking work for primates in our partner countries.

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How does the monkey compare?

Monkey vs Ape →Lemur vs Monkey →

Monkey: Frequently Asked Questions

How many monkey species are there?

Scientists recognise roughly 260 to 280 living monkey species, split between New World monkeys of the Americas and Old World monkeys of Africa and Asia. The count shifts as genetic studies refine species boundaries.

What is the difference between a monkey and a gorilla?

Gorillas are apes — they lack a tail, have broader chests and are much larger. Monkeys are generally smaller, have tails (except some stump-tailed macaques appear short-tailed), and belong to different evolutionary branches of the simian primates.

Can you have a pet monkey?

In most countries private monkey ownership is restricted or illegal, and welfare experts overwhelmingly advise against it. Monkeys need large social groups, climbing space, specialist diets and decades of care. The pet trade causes severe suffering.

Are monkeys endangered?

It depends on the species. Some adaptable monkeys remain common, while others — such as the golden snub-nosed monkey, golden lion tamarin, proboscis monkey and several spider monkeys — are Endangered or Critically Endangered due to habitat loss and hunting.

What do monkeys eat?

Most monkeys are omnivorous, eating fruit, leaves, seeds, insects and small animals. Diets vary: howler monkeys eat mainly leaves, capuchins crack nuts and hunt, marmosets gouge tree gum. Specialisation makes habitat type critical.

Where do monkeys live?

Monkeys live in tropical and subtropical regions of Central and South America, Africa and Asia. Habitats include rainforest, dry forest, savanna woodland, mangroves and — for some macaques — urban parks. The golden snub-nosed monkey is unusual in occupying snowy montane forest in central China.

Are monkeys dangerous?

Monkeys are not generally dangerous to people. Monkeys are tailed simian primates of the Americas, Africa and Asia — roughly 260+ species with forward-facing eyes, grasping hands and complex social groups. Give wild individuals space and do not corner or handle them.

How long do monkeys live?

A precise wild lifespan for monkeys is not firmly established in the sources cited on this guide. Monkeys are tailed simian primates of the Americas, Africa and Asia — roughly 260+ species with forward-facing eyes, grasping hands and complex social groups. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

How big is a monkey?

A Monkey is about Varies (IUCN status from Least Concern to Critically Endangered). Monkeys are tailed simian primates of the Americas, Africa and Asia — roughly 260+ species with forward-facing eyes, grasping hands and complex social groups.

Sources & References

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

Terms used on this page

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

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