QuestionMandrill
What Is the Largest Monkey in the World? Mandrills and More
The mandrill is usually named the largest monkey in the world. Adult males weigh about 19–30 kg (42–66 lb) in the wild and measure 70–95 cm (28–37 in) in head and body length. Some baboons, especially the chacma baboon, rival it in length and weight, so the title depends on how you measure.
Contents
Why the mandrill holds the title
The mandrill of west-central Africa combines a heavy, stocky build with a large head and powerful limbs. Wild adult males average roughly 25 kg (55 lb), and males in zoos are sometimes considerably heavier.
The mandrill also has the most extreme size difference between the sexes of any primate. Females weigh only about 10–15 kg (22–33 lb), less than half as much as many males. Because males are so big, the mandrill tops most lists that compare average male weight. Its short tail, just 7–10 cm (3–4 in), means it looks bulkier than long-tailed monkeys of similar weight.
The largest monkeys compared
| Monkey | Where it lives | Typical adult male weight | Notes |
|---|---|---|---|
| Mandrill | Cameroon, Equatorial Guinea, Gabon, Congo | 19–30 kg (42–66 lb) | Usually ranked largest on average weight |
| Chacma baboon | Southern Africa | 21–45 kg (46–99 lb), average about 32 kg | Longest monkey; big individuals may be heaviest |
| Olive baboon | Central and East Africa | Average about 24 kg (53 lb) | Very widespread; males have a mane |
| Drill | Cameroon, Nigeria, Bioko | Similar build to the mandrill | Endangered close relative |
| Proboscis monkey | Borneo | 16–22.5 kg (35–50 lb) | Largest monkey in Asia; huge nose |
| Gelada | Ethiopian highlands | About 18–20 kg (40–44 lb) | Grass-eater with a red chest patch |
| Muriqui | Atlantic Forest, Brazil | Up to about 15 kg (33 lb) | Largest monkey in the Americas |
Weights are approximate ranges for wild animals. Figures vary between studies and populations.
Mandrill vs baboon
Baboons are the mandrill’s main rivals. The chacma baboon of southern Africa is probably the longest monkey, with a head and body of up to about 115 cm (45 in) and a tail of 45–84 cm (18–33 in). Male chacmas weigh about 21–45 kg (46–99 lb), averaging around 32 kg (70 lb). The olive baboon is similar, with occasional very large males.
Mandrill and chacma baboon males have similar average weights, and comparisons depend on which populations are measured. Most reference books still name the mandrill as the largest monkey, but some experts argue the chacma baboon deserves the title on total length and maximum weight. Either way, these two species are clearly the giants of the monkey world.
Other big monkeys
The drill, the mandrill’s closest relative, is built in much the same way and is close in size, with males again far larger than females. It lives just north of the mandrill’s range and is listed as Endangered.
In Asia, the largest monkey is the proboscis monkey of Borneo. Males weigh about 16–22.5 kg (35–50 lb), roughly twice as much as females, and have an enormous, drooping nose that can exceed 10 cm (4 in). The gelada of Ethiopia is another large Old World monkey.
Monkeys of Central and South America are smaller overall. The biggest are the muriquis of Brazil, at up to about 15 kg (33 lb), followed by woolly monkeys, howler monkeys and spider monkeys.
Monkeys vs apes
Many people think of gorillas or chimpanzees when they hear “largest monkey,” but those animals are apes, not monkeys. Apes, which include gibbons, orangutans, gorillas, chimpanzees, bonobos and humans, have no tail, a more upright posture, flexible shoulders for swinging, and larger brains for their body size.
Apes are also much bigger. A wild male western gorilla usually weighs about 140–230 kg (310–500 lb), several times more than any monkey. For a full explanation of the differences, read Are chimpanzees monkeys?.
Were there bigger monkeys in the past?
Yes. Fossils show that some extinct monkeys were larger than any living species. Relatives of today’s gelada, in the genus Theropithecus, lived across Africa and beyond during the last few million years, and some of them were considerably heavier than modern mandrills or baboons. Exact weights are estimates based on bones and teeth, so they vary between studies.
Among living monkeys, there are also big differences between wild and captive animals. Zoo mandrills and baboons eat a rich, steady diet and get less exercise, so they can weigh much more than wild ones. When comparing species, scientists use measurements from wild adults to avoid this bias.
How to measure “largest”
There are several ways to decide which monkey is biggest, and they give slightly different answers. Average weight of adult males favors the mandrill. Total length, including the tail, favors long-tailed baboons. Maximum recorded weight can be skewed by a single unusual animal. That is why it is fair to call the mandrill the largest monkey while recognizing that the chacma baboon is a very close second.
Why males are so much bigger
In mandrills and baboons, males compete fiercely for access to females. Bigger, stronger males with longer canine teeth win more contests and father more young, so evolution has pushed male size up over many generations. Female size is shaped more by the energy needed to raise infants.
In mandrills, this competition also produced the male’s famous colors; see Why do mandrills have colorful faces?. Size differences between the sexes are much smaller in monkeys where males compete less, such as many South American species.
Frequently asked questions
Is a gorilla a monkey?
No. Gorillas are apes, like chimpanzees, orangutans and gibbons. Apes have no tail, larger brains for their size and different shoulders and skeletons. A gorilla is far bigger than any monkey, with wild males often weighing 140–230 kg (310–500 lb).
What is the largest monkey in the Americas?
The largest New World monkeys are the muriquis, or woolly spider monkeys, of Brazil's Atlantic Forest, which weigh up to about 15 kg (33 lb). Large howler monkeys and woolly monkeys come close but are generally lighter.
Is a baboon bigger than a mandrill?
They are very close. Chacma and olive baboons are often longer, especially counting the tail, and the heaviest individual baboons may outweigh most mandrills. On average body weight, adult male mandrills are usually ranked slightly ahead.
What is the smallest monkey?
The pygmy marmoset of the western Amazon is the smallest monkey. Adults weigh only about 100–140 g (3.5–5 oz) and measure around 12–15 cm (5–6 in) without the tail, so a male mandrill is more than 150 times heavier.
How strong is a mandrill?
Mandrills are very strong for their size, with powerful jaws that can crack hard seeds and canine teeth up to about 4.5 cm (1.8 in) long in males. There are no reliable measurements of their strength, so dramatic comparisons online should be treated with caution.
Sources and further reading
- Dixson, A. F., The Mandrill: A Case of Extreme Sexual Selection (2015)
- Animal Diversity Web (University of Michigan), "Mandrillus sphinx"
- Animal Diversity Web (University of Michigan), "Papio ursinus"
- Mittermeier, R. A., Rylands, A. B. and Wilson, D. E. (eds.), Handbook of the Mammals of the World, Vol. 3: Primates (2013)
Cite this page
“What Is the Largest Monkey in the World? Mandrills and More.” Animal Atlas, https://animals.bigworldlist.com/questions/what-is-the-largest-monkey/.
