The orangutans are two species of great apes with long arms and reddish, sometimes brown, hair native to Indonesia and Malaysia . They are the only extant species in the genus Pongo and the subfamily Ponginae, although that subfamily also includes the extinct Gigantopithecus and Sivapithecus genera. The orangutan is an official state animal of Sabah in Malaysia. Their name derives from the Malay and Indonesian words orang meaning "person" and hutan meaning "forest", or "person of the forest".

Orangutans are the most arboreal of the great apes, spending nearly all of their time in the trees, making a new nest in the trees every night. Adult males are about 4.5 ft (1.4 m) tall and up to 180 lb (82 kg) in weight. They are only found in rainforests on the islands of Borneo and Sumatra.

The gorilla, the largest of the living primates, is a ground-dwelling herbivore that inhabits the forests of Africa. Gorillas are divided into two species and (under debate as of 2006) either four or five subspecies. With 92-98% of its DNA being identical to that of a human, it is the next closest living relative to humans after the two chimpanzee species

Chimpanzee, often shortened to chimp, is the common name for the two extant species in the genus Pan. The better known chimpanzee is Pan troglodytes, the Common Chimpanzee, living in West and Central Africa. Its cousin, the Bonobo or "Pygmy Chimpanzee" as it is known archaically, Pan paniscus, is found in the forests of the Democratic Republic of the Congo. The Congo River forms the boundary between the two species.

Gibbons are the small apes that are grouped in the family Hylobatidae. The family is divided into four genera based on their diploid chromosome number: Hylobates (44), Hoolock (38), Nomascus (52), and Symphalangus (50). They occur in tropical and subtropical rainforests from northeast India to Indonesia and north to southern China, including the islands of Sumatra, Borneo and Java. The extinct Bunopithecus sericus is an extinct gibbon or gibbon-like ape which, until recently, was thought to be closely related to the Hoolock gibbons.

Also called the lesser apes, gibbons differ from great apes (chimpanzees, gorillas, orangutans and humans) in being smaller, pair-bonded, in not making nests, and in certain anatomical details in which they superficially more closely resemble monkeys than the great apes do. Gibbons are masters of their primary mode of locomotion, brachiation, swinging from branch to branch distances of up to 15 m (50 ft), at speeds as much as 56 km/h (35 mph). They can also make leaps of up to 8 m (27 ft), and walk bipedally with their arms raised for balance.

One unique aspect of gibbon physiology is that the wrist is composed of a ball and socket joint, allowing for biaxial movement. This greatly reduces the amount of energy needed in the upper arm and torso, while also reducing stress on the shoulder joint. They also have long hands and feet, with a deep cleft between the first and second digits of their hands. Their fur is usually black, gray, or brownish, often with white markings on hands, feet, and face. Some species have an enlarged throat sac, which inflates and serves as a resonating chamber when the animals call. This structure is enormous in a few species, equalling the size of the animal's head.

Gibbon skulls resemble those of the great apes, with very short rostra, enlarged braincases, and large orbits that face forward. Gibbons have the typical nose of catarrhine primates with nostrils that are close together and face forward and slightly downward. They lack cheek pouches and their stomach is not sacculated. Their teeth also are similar to the great apes, with molars that are bunodont and lack lophs. The upper molars usually have a cingulum, which is sometimes large. The canines are prominent but not sexually dimorphic.
Strongly territorial, gibbons defend their boundaries with vigorous visual and vocal displays. The vocal element, which can often be heard for long distances, consists of a duet between the mated pair, the young animals sometimes joining in. This eerie song can make them an easy find for poachers who engage in the illegal wildlife trade and in sales of body parts for use in traditional medicine. Most species are threatened or endangered, most importantly from degradation or loss of their forest habitat.

Gibbon species include the Siamang, the White-handed or Lar Gibbon, and the Hoolock gibbons. The Siamang, which is the largest of the 13 species, is distinguished by having two fingers on each hand stuck together, hence the generic and species names Symphalangus and syndactylus.

The Mandrill (Mandrillus sphinx) is a primate of the Cercopithecidae (Old-world monkeys) family, closely related to the baboons and even more closely to the Drill. Both the Mandrill and the Drill were once classified as baboons in genus Papio, but recent research has determined that they should be separated into their own genus, Mandrillus. The Mandrill is the world's largest monkey species. The word mandrill means "man-ape".

The Mandrill is recognized by its olive-colored fur and colorful face and rump amongst males, a coloration that grows stronger with sexual maturity; females have duller colors. This coloration becomes more pronounced as the monkey becomes excited. The coloration on the rump is thought to enhance visibility in the thick vegetation of the rainforest and aids in group movement.

Males can weigh up to 60 lb (30 kg), females about half as much. They can grow to be about 1 m long (39 in) and can survive up to 25 years in captivity. Females reach sexual maturity at about 3.5 years.

The Mandrill is found in the tropical rainforests of West Africa (Southern Nigeria, South Cameroon, Gabon, and Congo). It is a social creature and may be found in groups ranging from 5 to 50 individuals, led by an older dominant male. Six to seven of these groups may come together during the dry season to form a troop of over 200 individuals.

The Mandrill is an omnivore and acquires its food by foraging (mainly plants, insects and smaller animals) from the ground as it is terrestrial, although it may climb trees occasionally to sleep. Its main natural predators are leopards and cheetahs. Because of over-hunting by humans, the Mandrill has become endangered. The situation is exacerbated by deforestation causing Mandrill habitats to disappear.

Although the Mandrill does not normally hunt larger prey, on some occasions males have been observed to hunt and consume duiker (a small antelope). Despite this it is well adapted to fighting and is not to be provoked.

The macaques (genus Macaca) are Old World monkeys of the subfamily Cercopithecinae.

Aside from humans (genus Homo), the macaques are the most widespread primate genus, ranging from northern Africa to Japan. Twenty-two macaque species are currently recognised, and they include some of the monkeys best known to non-zoologists, such as the Rhesus Macaque (as the Rhesus Monkey), Macaca mulatta, and the Barbary Macaque (as the Barbary Ape), M. sylvanus, a colony of which lives on the Rock of Gibraltar. Although several species lack tails, and their common names therefore refer to them as apes, these are true monkeys, with no greater relationship to the true apes than any other Old World monkeys.

The baboons are some of the largest non-hominid members of the primate order; only the Mandrill and the Drill are larger. In modern scientific use, only members of the genus Papio are called baboons, but previously the closely related Gelada (genus Theropithecus) and two species of Mandrill and Drill (genus Mandrillus) were grouped in the same genus, and these monkeys are still often referred to as baboons in everyday speech. The word "baboon" comes from "babouin", the name given to them by the French naturalist Buffon. Papio belongs to family Cercopithecidae, in subfamily Cercopithecinae.

Black-and-white colobus are the Old World monkeys which bear a striking resemblance to skunks. They are of the genus Colobus and are closely related to the red colobus monkeys of genus Piliocolobus. The word "colobus" comes from Greek ekolobóse "he cut short" and is so named because its thumb is a stump.

Colobinae is a subfamily of the Old World monkey family that includes 58 species in 10 genera, including the skunk-like black-and-white colobus, the large-nosed Proboscis Monkey, and the gray langurs, sacred to India. Some classifications split the colobine monkeys into two tribes, while others split them into three groups. Both classifications put the two African genera Colobus and Piliocolobus in one group, both genera distinct in that they have a stub thumb. The various Asian genera are placed into one or two other groups. Analysis of mtDNA confirms that the Asian species form two distinct groups, one of which contains langurs, with the "odd-nosed" species in the other, but suggests that the gray langurs are not too closely related to either.

Colobines are medium sized primates with long tails and diverse colorations. It is remarkable that nearly all of the young animals differ in their coloring substantially from the adults.

Most species are arboreal, although some live a more terrestrial life. They are found in many different habitats of the different climate zones (rain forests, mangroves, mountain forests and savanah), but not in deserts and other dry areas. They live in groups, but in different group forms.

They are almost exclusively herbivores, which predominantly nourish themselves on leaves, flowers and fruits. They occasionally eat insects and other small animals. To aid in digestion, particularly for hard to digest leaves, they have a multipart, complex stomach. Unlike the other subfamily of Old World monkeys, the Cercopithecinae, they possess no cheek pouches.

Gestation averages six to seven month. Young are weaned for approximately one year and are mature at 3 to 6 years. Their life expectancy is approximately 20 years.

Lemurs are members of a class of primates known as prosimians and make up the infraorder Lemuriformes. This type of primate was the evolutionary predecessor of monkeys and apes (simians). The term "lemur" is derived from the Latin word lemures, which means "spirits of the night". This likely refers to many of the nocturnal lemur species and their large, reflective eyes. The term is generically used for the members of the four lemuriform families, but it is also the genus of one of the lemuriform species. The two flying lemur species are not lemurs, nor are they even primates.

The Drill (Mandrillus leucophaeus) is a primate of the Cercopithecidae (Old-world Monkeys) family, closely related to the baboons and even more closely to the Mandrill.

The Drill is similar in appearance to the Mandrill, but lacks the colorful face. It is found only in Cameroon, Nigeria, north of the Sanaga River and on the coastal island of Bioko, part of Equatorial Guinea.

The Drill is one of Africa's most endangered primates.

The marmosets are the genus Callithrix of New World monkeys. One species not classified in this genus also has common names including the word "marmoset", the Goeldi's Marmoset (Callimico goeldii). This article deals only with the 18 species currently classified in Callithrix.

Most marmosets are about 20 cm in length. Relative to other monkeys, they show a number of apparently primitive features: they have claws rather than nails, and tactile hairs on their wrists. They lack wisdom teeth, and their brain layout seems to be relatively primitive. Their body temperature is unusually variable, showing as much as 4 Celsius degrees (7 Fahrenheit degrees) change in a day.

Marmosets are highly active, living in the upper canopy of forest trees, and feeding on insects, fruit and leaves. They have long lower incisors, which enable them to chew holes in the trunks or branches of trees so as to harvest the gum inside; some species are specialised feeders on gum.

Marmosets live in small family groups consisting of a mated pair and their offspring, thus making marmosets (along with gibbons) some of the few monogamous primates. They are thought to be territorial. In most species, twins are usually born, though triplets are not unknown. A high degree of paternal care is shown, and the male usually carries the infants on his back as the family group moves around.

The Potto (Perodicticus potto) is a strepsirrhine primate from the Lorisidae family. It is the only species in genus Perodicticus. The name "Potto" possibly comes from the African word "pata", which means tailless ape. The Potto is also known as Bosman's Potto, after its supposed discoverer, and in some English-speaking parts of Africa it is called a Softly-softly.

The tarsiers are the members of the Tarsius genus of prosimian primates, monotypic in the Tarsiidae family and Tarsiiformes infraorder. The entire infraorder was previously classified in the Strepsirhini suborder, but now classified in the Haplorrhini suborder, although they are not considered to be monkeys. Evidence for the position of Tarsier in the primate tree came for example from retrotransposon presence/absence data. Tarsiers have enormous eyes and long feet. Their feet have extremely elongated tarsus bones, which is how they got their name, and most are nocturnal. They are primarily insectivorous, and catch insects by jumping at them. They are also known to prey on birds and snakes. Gestation takes about six months, and tarsiers give birth to single offspring. Once found in Asia, Europe and North America, tarsiers are now only found on several Southeast Asian islands including the Philippines, Sulawesi, Borneo, and Sumatra. Their conservation status has been classified as "Lower Risk/Conservation Dependent". When caged, some tarsiers have been known to injure and even kill themselves because of the stress. They also have the longest continuous fossil record of any primate, and the fossil record suggests that their dental pattern and shape hasn't changed in 45 million years. Unlike many nocturnal animals, tarsiers lack a light-reflecting area (tapetum lucidum) of the eye. They also have a fovea, atypical for nocturnal animals.