Old and New World Monkeys

Monkeys are either classified as Old World Monkeys, or New World Monkeys. The species which fall in the former group are those who hail from Africa, central to southern Asia, Japan and India. While those whose home ground happens to be Mexico, Central and South America, are put under the latter group. Monkeys are different from apes or prosimians (defined as primitive primates bearing large ears and eyes, they usually have nocturnal habits). Many may be unaware of the fact that monkeys are smaller and longer-tailed.

Largest and Smallest Monkey Species

Largest Species of Monkey

A male mandrill monkey showing its vivid blue and red muzzle markings
The mandrill's striking face colors are the most vivid of any mammal.

The largest species of monkeys is the Mandrill. It is often mistaken for an ape because of its size (1 - 3ft).

Smallest Monkey

A tiny pygmy marmoset perched on a human thumb, showing its true miniature scale
The pygmy marmoset fits in the palm of your hand, it is the world's smallest monkey.

The smallest monkey in the world does not grow more than 5 - 6 inches. This species is known as the pygmy marmoset.

Monkeys never catch cold!

Here is a surprising fact: monkeys never catch the common cold. The cold is a problem for us humans, but not for monkeys. Unlike gorillas and chimpanzees, monkeys simply don't get it.

Monkey and its table manners

Monkey eating a banana, carefully peeling the skin first
A monkey peels a banana before eating, something they do consistently in the wild.

Monkeys are also known for their table manners. They never eat a banana without peeling the skin first.

Teeth of Monkeys

A baboon baring its teeth, showing the full set of 32 Old World monkey teeth
Old World monkeys, like this baboon, have 32 teeth, four more than their New World relatives.

Monkeys belonging from the Old World family grow 32 teeth while those from the New World, 28.

The Howler Monkey

A howler monkey roaring from its perch high in the rainforest canopy
The howler monkey's enlarged hyoid bone acts as a resonating chamber, amplifying its roar to extraordinary volume.

If you can hear a monkey howling from a distance of 3 miles or more, then know that it is the howler monkey. The species is reputed to be the loudest animal on land, and the largest of the New World monkeys.

Take the Monkey Facts Quiz!

5 quick questions. How much do you really know about monkeys?

Monkey brain, a delicacy!

In parts of South Asia, China, and Africa, a dish made from monkey brains is considered a delicacy. It is one of the more unusual (and controversial) facts about how monkeys interact with human cultures around the world.

Give and take!

Two monkeys grooming each other, one picking through the other's fur
Grooming builds social bonds, and the groomer earns a meal of insects found in its partner's coat.

Monkeys like to stay clean and groomed. That is why a monkey would have another one to do a barber's job. The barber monkey gets paid in the form of bugs from the customer's coat. So it's a give and take concept!

The Unique Spider Monkey

A spider monkey hanging from a tree branch by its long prehensile tail
The spider monkey's prehensile tail acts like a fifth hand, gripping branches with enough strength to hold its full body weight.

The spider monkey can hang on to a branch by using only the tip of its tail. Also, it can be seen swinging from one branch to the other. Most monkeys simply run across the branches.

Beware of its signs!

A toque macaque monkey yawning widely, displaying its teeth as a warning signal
That wide-open yawn is not sleepiness, in monkey language it means 'back off.'

If a monkey yawns at you, then better let it be because it is most likely that you are making the animal angry. Also, if you see a monkey grinning or pulling its lip, then these are signs of aggression.

Frequently Asked Questions

What is the difference between Old World and New World monkeys?

Old World monkeys come from Africa, central and southern Asia, Japan and India. New World monkeys live in Mexico, Central and South America.

Which is the largest species of monkey?

The Mandrill, which can grow 1-3 feet and is often mistaken for an ape.

What is the smallest monkey in the world?

The pygmy marmoset, which grows no more than 5-6 inches.

What does it mean when a monkey yawns at you?

It is a warning sign of aggression. A yawning, grinning, or lip-pulling monkey is most likely angry.

Can monkeys catch a cold?

No, unlike gorillas and chimpanzees, monkeys do not catch the common cold.

The cold survivors

A Japanese macaque (snow monkey) sitting in a snow-covered landscape in Nagano, Japan
Japanese macaques in Nagano are famous for warming up in natural hot springs during the bitter winter months.

Some monkeys can handle truly freezing weather. Snow monkeys, also known as Japanese macaques, can survive temperatures as low as -10 degrees Celsius. They are even famous for warming up in natural hot springs during winter.

The endangered monkey species

A golden lion tamarin with its vivid orange mane perched on a branch in the Atlantic Forest, Brazil
The golden lion tamarin's spectacular orange mane sets it apart, but its forest home in Brazil is rapidly disappearing.

The Golden Lion Tamarin is a majestic animal bearing a striking orange mane. But, thanks to human activities such as poaching, mining, and urbanization to name a few, this species is listed as endangered by the IUCN (International Union for Conservation of Nature).

Mating Habit

During mating, the female monkey gives out loud and distinctive calls. Scientists believe these calls play an important role in the mating process. This behavior is especially well-studied in the Barbary macaque species.

The White-faced Capuchin

A white-faced capuchin monkey looking attentively at the camera, its pale face framed by dark fur
Capuchin monkeys are considered among the most intelligent of all monkey species, they have even been trained to assist people with disabilities.

Monkeys can be cheeky, but they can also be incredibly helpful. Capuchin monkeys are put through extensive training programs to help people such as quadriplegics. They learn to open bottles, wash a patient's face, and even operate a microwave.

Breeding Time No Bar

Monkeys do not wait for spring time to get cozy with their mates. Most of them can breed at any time of the year.

Common Species of Monkeys

There are over 260 known species of monkey. Here are some of the best-known:

  • Golden Lion Tamarin
  • Capuchin Monkey
  • Japanese Macaque
  • Mandrill
  • Gelada Monkeys
  • Howler Monkey
  • Spider Monkey
  • Rhesus Monkey
  • Vervet Monkeys
  • Olive Baboons
  • Squirrel Monkey
  • Proboscis Monkey

Monkeys (along with all the other animals on Earth) show us just how wide and varied nature really is. They are a reminder of how connected we all are. Without them there would be no ecological pyramid, no biodiversity, and a much quieter world. Chi hoo ooh! That's 'cheers' in monkey language!

Explore More Animals

A Complete List of All Types of MonkeysA Complete List of All Types of MonkeysFrom the pygmy marmoset (5 inches tall) to the giant Mandrill: discover every major type of monkey (New World and Old World) with photos, fun facts, and a qui Monkey Habitat: Where Do Monkeys Live?Monkey Habitat: Where Do Monkeys Live?There are more than 260 extant monkey species known today. Discover where monkeys live (from Amazon rainforests to Asian mountains) plus habitat facts, a quiz Facts About the Astoundingly Colorful MandrillsFacts About the Astoundingly Colorful MandrillsMandrills are the largest and most colorful monkeys in the world. Natives to central Africa, these fascinating primates are listed as vulnerable. Discover their Staggering Facts About Spider Monkeys You'd Never BelieveStaggering Facts About Spider Monkeys You'd Never BelieveSpider monkeys are the 'trapeze artists' of the jungle, swinging through the canopy on a prehensile tail stronger than their own body weight. Discover how they