Old World Monkeys II (Cercopithecinae)

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Old World monkeys II

(Cercopithecinae)

Class Mammalia

Order Primates

Family Cercopithecidae

Subfamily Cercopithecinae


Thumbnail description
Medium-sized mammals with forward-facing, quite large eyes, relatively large brains and a quadrupedal pattern of locomotion involving grasping hands and feet

Size
2 lb 12 oz (1.25 kg) to 48 lb (21.7 kg)

Number of genera, species
11 genera; 72 species

Habitat
Wide range of habitats, ranging from semi-arid scrub with only sparse vegetation to dense evergreen tropical rainforest

Conservation status
Critically Endangered: 1 species; Endangered: 8 species; Vulnerable: 10 species; Near Threatened: 16 species; Data Deficient: 3 species

Distribution
Predominantly occur in Africa south of the Sahara; macaques occur outside Africa, having a wide distribution throughout Asia and Southeast Asia

Evolution and systematics

The higher primates (suborder Anthropoidea) are divided into the broad-nosed monkeys of the New World (infraorder Platyrrhini) and the narrow-nosed monkeys and apes of the Old World (infraorder Catarrhini). The Old World monkeys and apes, which occur in Africa, Asia and Southeast Asia, are uniformly characterized by a dental formula of (I2/2 C1/1 P2/2 M3/3) × 2 = 32, differing from all New World monkeys by reduction in the number of premolars from three to two in each tooth row. All Old World monkeys and apes have trichromatic color vision comparable to that of humans. As a group, the Old World monkeys are distinguished from the apes by the presence in both upper and lower jaws of four-cusped molars with the cusps linked in pairs to form transverse cutting ridges (bilophodonty). Furthermore, all Old World monkeys possess well-developed hardened sitting pads (ischial callosities) on the buttocks, supported by broad, roughened bony flanges (ischial tuberosities) on the pelvis. Among the apes, only the gibbons show a similar development. The Old World monkeys are divided into two main groups, the cheek-pouched monkeys (subfamily Cercopithecinae) and the leaf-monkeys (subfamily Colobinae). Defining features of these two groups are related to their feeding habits. Whereas all cercopithecine monkeys possess cheek pouches for the temporary storage of food, leaf-monkeys have a complex, multi-chambered stomach as an adaptation for digestion of plant cell walls in their leaf-rich diet with the aid of symbiotic bacteria. There is also a consistent and immediately obvious difference in skull morphology, in that the distance

between the eye sockets (interorbital distance) is small in cheek-pouched monkeys and large in leaf-monkeys.

Two tribes can be recognized among the cercopithecine monkeys: the Cercopithecini (guenons) and the Papionini (baboons, geladas, mangabeys, drill, mandrill, and macaques). The guenons are generally smaller and more arboreal than the baboons and their relatives, which tend to be large-bodied and at least partially terrestrial; but there is some degree of overlap in these features. For instance, the patas monkey (Erythrocebus patas) is a member of the guenon tribe but is quite large-bodied and predominantly terrestrial.

Old World monkeys commonly show some degree of sexual dimorphism, in which males and females differ in features other than those directly related to reproduction. Males and females of a species can differ markedly in fur coloration, in overall body size and in the size of the canine teeth, although these features can vary to some extent independently. The most striking example of sexual dimorphism in all three aspects is provided by the mandrill (Mandrillus sphinx), in which males weigh more than twice as much as females, have strikingly large canine teeth and are more brightly colored.

Chromosomal and molecular evidence indicates that the two tribes Cercopithecini and Papioni are both monophyletic, each being derived from a separate common ancestor after the cheek-pouched monkeys diverged from the leaf-monkeys. Within the Cercopithecini, there appear to be two main clusters, one formed by most of the forest-living guenons (Cercopithecus species) and the other containing the talapoins (Miopithecus), the vervets or grivets (Chlorocebus), l'Hoest's guenon (Cercopithecus lhoesti), and the patas monkey (Erythrocebus patas). Within the Papionini, there is a basic division between the baboons, macaques, and geladas on one branch and the mandrills on another. Unexpectedly, the Old World monkeys known as mangabeys, which were all originally classified as species of the genus Cercocebus, turned out to belong to two distinct lineages. The genus name Cercocebus is now reserved for more terrestrial species related to the mandrill, whereas the genus name Lophocebus is used for more arboreal species related to baboons.

The early fossil history of the Old World monkeys is still poorly documented. Two early Miocene forms from Africa, from deposits dated at about 20 million years ago (mya) are

Prohylobates and Victoriapithecus, both of which have bilophodont (two-ridged) molar teeth. These early fossil forms were originally known only from isolated teeth and jaw fragments, and this is still the case for Prohylobates. However, a fairly complete skull and parts of the postcranial skeleton have been reported for Victoriapithecus, and as a result it is known that this genus was characterized by a short interorbital distance and by possession of ischial tuberosities on the pelvis. But it is unclear whether Victoriapithecus is specifically related to modern cheek-pouched monkeys, as the small interorbital distance suggests. It is not until the late Miocene and the Pliocene, less than 10 mya, that fossil remains of Old World monkeys become relatively well documented, and by that stage it is certainly possible to distinguish between cercopithecines (relatives of cheek-pouched monkeys) and colobines (relatives of leaf-monkeys). Cercopithecine monkeys are comparatively common in Pliocene deposits of Africa. Many of them resemble modern baboons (e.g. Dinopithecus, Dolichopithecus and Gorgopithecus), and there are also relatives of the modern gelada, some of them almost as big as a female gorilla, which are placed in the same genus Theropithecus. During warm interglacial periods of the middle Pleistocene, macaques related to the modern Barbary macaque (Macaca sylvanus) were present in central Europe, but they subsequently became restricted to North Africa.

Physical characteristics

Coloration of the body fur is often relatively inconspicuous and occasionally cryptic, generally being darker dorsally and paler ventrally. The face is usually virtually naked, although in some species there is a beard-like tuft of hair on the chin. However, in many cases the fur and skin on the face and sometimes on other areas of the body are conspicuously patterned, notably in various guenons, where species-specific coloration patterns on the head are commonly emphasized by characteristic head movements. Striking color contrasts are also frequently present in the genital region. In males, the scrotum and/or penis are often distinctively colored, while in females of some species there is often a conspicuous sex skin

that changes in color and size over the course of the ovarian cycle. The most colorful species is undoubtedly the mandrill (Mandrillus sphinx). In this species, the faces of males have a bright red nose flanked by blue, ridged paranasal bulges along with white whiskers, and there is a large, orange-yellow beard, while the rump is also colored red and blue and the penis is bright red. Females are similarly, although less brightly, colored; but they also have prominent sexual swellings that are bright red at peak inflation.

In the head, the eyes are always directed directly forwards and the snout is mildly to strongly elongated. In common with other higher primates, a rhinarium (a naked, moist area of skin around the nostrils present in most mammals) is always completely lacking. The nostrils are relatively close-set and point downward. Cheek pouches are consistently present, but the degree of development varies from species to species. The dental formula, which is the same in all Old World monkeys and apes, is (I2/2 C1/1 P2/2 M3/3) × 2 = 32. The canine teeth are typically large, stabbing teeth, and the rear edges of the upper canines are honed against the leading edges of the anterior premolars in the lower jaw. The molars in both upper and lower jaws are bilophodont. Cercopithecine monkeys typically walk and run quadrupedally both in the trees and on the ground, and the arms and legs are of approximately equal length. In the trees, they are agile climbers. On the hand, the thumb is always well developed, and fine manipulative actions are particularly prevalent in terrestrial species. In all Old World monkeys, including leaf-monkeys (colobines), well-developed hardened sitting pads (ischial callosities) are present

on the buttocks, and these are supported by broad, roughened bony flanges (ischial tuberosities) on the pelvis. The tail is very variable in length, being very long in some species and reduced to a small stump in others. As a rule, arboreal species tend to have a relatively long tail, whereas marked reduction of the tail is found in species that spend much of their time on the ground. Head and body length varies from 14 in (35 cm) to 30 in (75 cm), while tail length varies from practically zero to 34 in (86 cm), according to species. Body mass ranges from 2 lb 12 oz (1.25 kg) for the diminutive talapoin (Miopithecus talapoin) to 48 lb (31.6 kg) for a male mandrill (Mandrillus sphinx).

Distribution

Cheek-pouched monkeys of the subfamily Cercopithecinae are largely confined to Africa south of the Sahara, where they are very widely distributed. The only cercopithecine monkeys to occur outside Africa are the macaques (genus Macaca), which occur widely in Southeast Asia. Just one macaque species, the Barbary macaque (Macaca sylvanus) is found in Africa, occurring north of the Sahara in Algeria and Morocco.

Habitat

Cheek-pouched monkeys occur in a remarkably wide range of habitats, spanning the spectrum from semi-arid scrub vegetation marked by strictly seasonal rainfall to highly humid evergreen tropical rainforest with year-round rainfall. Most species depend upon trees to some extent, at least for sleeping sites during the night. Most species typically inhabit evergreen tropical rainforest. This applies to most guenons (genera Allenopithecus and Cercopithecus), talapoins (genus Miopithecus), mangabeys (genera Cercocebus and Lophocebus), drills and mandrills (genus Mandrillus) and many Asiatic macaque species (genus Macaca). By contrast, baboons (genus Papio), geladas (genus Theropithecus), a few guenons (genera Chlorocebus and Erythrocebus), and some macaque species (e.g. the Barbary macaque, Macaca sylvanus) commonly live in relatively open, dry-country habitats. The most extreme example of the latter is probably provided by the chacma baboon (Papio ursinus), which lives under extremely dry, almost desert-like conditions in some parts of southern Africa.

Behavior

All members of the subfamily Cercopithecinae are diurnal. Most species are essentially arboreal, but there are also

numerous species that have become adapted for terrestrial activity. In all cases, locomotion is typically quadrupedal. All cheek-pouched monkeys live in gregarious social groups that move around and feed as relatively cohesive units, organized in some cases as harem groups with a single adult male (one-male groups) and in others as groups containing several adult males (multimale groups). Monogamy is extremely rare as a social system in cercopithecine monkeys. Forest-living guenons of the genus Cercopithecus, patas monkeys (Erythrocebus), hamadryas baboons (Papio hamadryas), and geladas (Theropithecus) all form one-male groups. In some species that exhibit one-male groups, surplus males form bachelor male groups, and it is possible for several harem groups and bachelor male groups to live in large herds, as is the case with hamadryas baboons and geladas. As a general rule, females tend to stay in their natal groups, whereas males migrate at round the time of sexual maturity.

Feeding ecology and diet

As a rule, cheek-pouched monkeys feed predominantly on relatively high-energy foods such as fruits, seeds, insects, and

(occasionally) other vertebrates. Although many species also eat leaves, these typically represent a minor part of the diet and relatively nutritious young leaves are generally preferred. However, the bilophodont teeth that characterize all Old World monkeys probably represents an adaptation for mastication of resistant material such as leaves, so it seems likely that the common Old World ancestor of both cheek-pouched monkeys (subfamily Cercopithecinae) and leaf-monkeys (sub-family Colobinae) was folivorous at least to some extent. On the other hand, the cheek pouches that characterize all cercopithecine monkeys probably constitute an adaptation for temporary storage of small, easily collected food items such as fruits and seeds, so their development in the common ancestor of Cercopithecinae probably presumably a shift towards increased consumption of such food items. With respect to diet, the most aberrant species among the cheek-pouched monkeys is the gelada (Theropithecus gelada), which feeds extensively on grass shoots, seeds and roots and shuffles along on its hindquarters much of the day while foraging.

Reproductive biology

Monogamy is rare in cercopithecine monkeys; most are polygamous.

Single births are typical, although twins are born very occasionally, and two teats (mammae) are consistently present in the chest region. All species have a menstrual cycle lasting approximately a month and marked by externally visible menstrual bleeding. In many species, females have a conspicuous sex skin in the genital region that changes in coloration and size over the course of the ovarian cycle. Maximum swelling and the most prominent degree of coloration (commonly bright red) occur around the time of ovulation, approximately halfway between menstrual episodes. Conspicuous sex swellings are found in baboons, mandrills, some mangabeys, short-tailed macaques, swamp monkeys and talapoins, but they are less prominent or virtually absent in long-tailed macaques and forest-living guenons and other mangabeys. Geladas are highly unusual in that the sex skin is located on the chest, as a patch bordered by vesicles that varies in color and prominence over the ovarian cycle. This special development is undoubtedly linked to the fact that geladas spend much of the day shuffling along on their hindquarters while foraging. Placentation is of a highly invasive hemochorial type. The gestation period is long, varying between 162 days for the smallest species, the talapoin (Miopithecus talapoin), and 187 days for one of the largest, the chacma baboon (Papio ursinus).

Conservation status

One species is Critically Endangered (Macaca pagensis), eight species are Endangered (Cercopithecus diana, Cercopithecus erythrogaster, Cercopithecus preussi, Cercopithecus sclateri, Macaca maurus, Macaca nigra, Macaca silenus, and Mandrillus leucophaeus), 10 are Vulnerable (Cercopithecus erythrotis, Cercopithecus solatus, Macaca arctoides, Macaca assamensis, Macaca cyclopis, Macaca leonina, Macaca nemestrina, Macaca sinica, Macaca sylvanus, and Mandrillus sphinx), and 16 are Near Threatened (Allenopithecus nigroviridis, Cercocebus atys, Cercocebus galeritus, Cercocebus torquatus, Cercopithecus hamlyni, Cercopithecus lhoesti, Lophocebus aterrimus, Macaca fascicularis, Macaca hecki, Macaca mulatta, Macaca nigrescens, Macaca thibetana, Macaca tonkeana, Papio hamadryas, Papio papio, and Theropithecus gelada). Three species are listed as Data Deficient (Cercopithecus dryas, Macaca fuscata, and Macaca ochreata).

Significance to humans

Cheek-pouched monkeys are commonly hunted for food (bushmeat) in Africa, Asia and Southeast Asia, although they are often protected at least to some extent by local customs in Asia and parts of Southeast Asia, as is the case with rhesus macaques (Macaca mulatta) and bonnet macaques (Macaca radiata) in India. Monkeys of the subfamily Cercopithecinae have also been used extensively in biomedical research because they are relatively closely related to humans. The rhesus macaque has long been established as a standard laboratory species and, among other things, served as a basic model for the study of reproductive processes and maternal behavior. Other macaque species, various baboons and some guenon species have also been widely used in biomedical research.

Species accounts

List of Species

Allen's swamp monkey
Patas monkey
Angolan talapoin
Grivet
Moustached guenon
Rhesus macaque
Barbary macaque
Gray-cheeked mangabey
Collared mangabey
Hamadryas baboon
Gelada
Mandrill

Allen's swamp monkey

Allenopithecus nigroviridis

subfamily

Cercopithecinae

tribe

Cercopithecini

taxonomy

Allenopithecus nigroviridis (Pocock, 1907), upper Congo River, Zaire. This species was originally included in the genus Cercopithecus, but it resembles members of the tribe Papionini in a number of features and is best allocated to the separate genus Allenopithecus.

other common names

English: Allen's swamp guenon; French: Cercopithèque d'Allen; German: Schwarzgrüne Meerkatze.

physical characteristics

Fur greenish gray dorsally and pale gray (sometimes with an orange tinge) ventrally. Webbing is present between the fingers and toes. The ischial callosities are fused across the mid-line in adult males. In males, the scrotum is pale blue. Average head and body length: 18 in (45 cm); average tail length: 17.5 in (43.5 cm). There is marked sexual dimorphism in body size. Body mass: 13 lb 9 oz (6.15 kg) for males and 7 lb (3.20 kg) for females.

distribution

Central Congo basin in eastern Congo-Brazzaville and western Democratic Republic of the Congo (Zaïre).

habitat

Swampy forest areas and regularly flooded parts of riverine forests.

behavior

Diurnal and semi-arboreal, typically occurring relatively low down in the forest. Swim well and may dive into rivers to escape from predators. Live in multimale groups of moderate size, 23 to 57, with very few rules.

feeding ecology and diet

Often forage on the ground. Diet primarily consists of fruit, supplemented by flowers, nectar, roots and animal prey (e.g., insects and, reputedly, fish).

reproductive biology

Polygamous. Single births are typical. Females have a prominent sexual swelling that varies in size and coloration across the cycle. Little-studied in captivity, so reproductive characteristics such as the gestation period are unknown.

conservation status

Listed as Near Threatened.

significance to humans

Hunted for bushmeat, particularly by hunters operating from boats.


Patas monkey

Erythrocebus patas

subfamily

Cercopithecinae

tribe

Cercopithecini

taxonomy

Erythrocebus patas (Schreber, 1775), Senegal. The patas monkey is sometimes included in the genus Cercopithecus, but it is so distinctive in many features that recognition of the separate genus Erythrocebus is surely justified. Four subspecies have been recognized.

other common names

English: Hussar monkey, red monkey; French: Patas; German: Husarenaffe.

physical characteristics

This is the largest species in the guenon tribe Cercopithecini and there is pronounced sexual dimorphism in body size, with males weighing almost twice as much as females. The body fur is bright reddish orange dorsally and white ventrally. Both sexes have a conspicuous white mustache. In non-pregnant females, the nose is black and there is a black band across the temples and above the eyes. In males, the scrotum is bright blue. The limbs are long and slender, and the patas monkey is

the only species that shows locomotion using the tips of the fingers (digitigrady) rather than the palms of the hand (palmi-grady) as in other primates. Head and body length: 26 in (65.5 cm) for males and 19.5 in (49.0 cm) for females; tail length: 27.5 in (68.5 cm) for males and 20.5 in (51.0 cm) for females. Body mass: 27 lb 5 oz (12.4 kg) for males and 14 lb oz (6.5 kg) for females.

distribution

Very large range in sub-Saharan Africa, extending from Senegal in the west to the borders of Ethiopia in the east and southward in East Africa down to Serengeti and Mount Kilimanjaro.

habitat

Semi-desert, grassland, and woodland savanna characterized by a pronounced dry season.

behavior

Diurnal and predominantly terrestrial, although they occasionally climb trees while foraging and sleep in trees at night. Typically form one-male groups of moderate size, with surplus males forming bachelor groups. However, extra-group males commonly invade harem groups and mate with the females during the breeding season.

feeding ecology and diet

Feeds on fruits, seeds, gums, grasses, and a variety of animal prey, including insects, lizards, and birds' eggs.

reproductive biology

Polygamous. Single births are typical. Females do not have a sexual swelling. There are well-defined mating and birth seasons. Gestation period 167 days. Unusually, there is a change in facial color in females during late pregnancy: the black coloration is lost from the nose and from the band across the temples and above the eyes, and does not reappear until about six weeks after birth.

conservation status

Not currently regarded as threatened.

significance to humans

None known.


Angolan talapoin

Miopithecus talapoin

subfamily

Cercopithecinae

tribe

Cercopithecini

taxonomy

Miopithecus talapoin (Schreber, 1774), Angola. It has been customary to recognize only a single species in the genus Miopithecus talapoin, but the population in Cameroon (south of the River Sanaga), Río Muni and Gabon can be distinguished as a separate species, Miopithecus ogouensis.

other common names

English: Angolan dwarf guenon; French: Talapoin d'Angola; German: Zwergmeerkatze.

physical characteristics

Talapoins are the smallest Old World monkeys and almost certainly evolved from a larger-bodied ancestor by dwarfing. The fur is coarsely banded yellow-and-black dorsally and white or grayish white ventrally. The nose is back and the skin bordering the face is also black. In males, the scrotum is colored pink medially and blue laterally. There is mild sexual dimorphism in body size. Average head and body length: 16 in (40

cm); average tail length: 21 in (52.5 cm). Body mass: 3 lb 1 oz (1380 g) for males and 2 1b 10 oz (1120 g) for females.

distribution

Equatorial West Africa in western Democratic Republic of the Congo and the coastal region of Angola.

habitat

Occur in both primary and secondary gallery, mangrove, and swamp forests.

behavior

Diurnal and predominantly arboreal, although they may occasionally descend to the ground while foraging. Talapoins are good swimmers and commonly sleep on branches overhanging rivers so that they can dive to escape from predators. Live in multimale groups usually of moderate size, but that can reach 100 or more individuals.

feeding ecology and diet

Diet consists of approximately equal proportions of fruits and animal prey, including various arthropods (mainly insects), small vertebrates, and eggs.

reproductive biology

Polygamous. Single births are typical. Females have a prominent sexual swelling that varies in size and coloration across the cycle. Gestation period 162 days.

conservation status

Not currently regarded as threatened.

significance to humans

Occasionally hunted as a source of bushmeat, although the small body size makes this relatively unprofitable.


Grivet

Chlorocebus aethiops

subfamily

Cercopithecinae

tribe

Cercopithecini

taxonomy

Chlorocebus aethiops (Linnaeus, 1758), Sennaar, Sudan. It has been customary to include the grivet in the genus Cercopithecus along with other guenons, but grivets and their close relatives are sufficiently distinctive to warrant the separate genus name Chlorocebus. Molecular studies indicate that there was a relatively early separation between the grivet lineage and typical forest-living guenons in the genus Cercopithecus.

other common names

English: Vervet monkey, green monkey; French: Grivet, cercopithèque vert; German: Graugrüne Meerkatze.

physical characteristics

Fur grizzled olive agouti dorsally and white ventrally. The skin on the abdomen has a blue hue. The facial skin is black. Conspicuous long white whiskers are present on the cheeks, and there is a narrow white band above the eyes. There is a tuft of white hair at the base of the tail, and in males the scrotum is bright blue, contrasting with the bright red coloration of the penis. This pattern provides the basis for the "red, white, and blue display" of males. There is mild sexual dimorphism in body size. Head and body length: 19.5 in (49.0 cm) in males and 17 in (42.5 cm) in females; tail length: 25 in (63.0 cm) in males and 22 in (56.0 cm) in females. Body mass: 9 lb 6 oz (4.25 kg) for males and 6 lb 10 oz (3.00 kg) for females.

distribution

Occurs east of the White Nile in Sudan, Eritrea, and through Ethiopia as far as the Rift Valley.

habitat

Savanna woodland and riverine forest characterized by a pronounced dry season.

behavior

Diurnal and semi-arboreal, feeding both in the trees and on the ground. Sleeps in trees at night. Lives in multimale groups of moderate size.

feeding ecology and diet

Broad diet including fruits, seeds, some leaves and animal prey (insects, reptiles, birds and small mammals).

reproductive biology

Polygamous. Single births are typical. Females do not have a sexual swelling, but the perineal skin changes from white to pink around the time of ovulation. Gestation period 163 days.

conservation status

Not currently regarded as threatened.

significance to humans

Grivets are occasionally hunted as a source of bushmeat.


Moustached guenon

Cercopithecus cephus

subfamily

Cercopithecinae

tribe

Cercopithecini

taxonomy

Cercopithecus cephus (Linnaeus, 1758), Africa. The genus Cercopithecus is the most species-rich among the cheek-pouched monkeys, with a total of at least 26 species. Three subspecies have been recognized within the species Cercopithecus cephus.

other common names

English: Moustached monkey; French: Cercopithèque moustachu; German: Blaumaulmeerkatze.

physical characteristics

Fur brown with rufous tint dorsally and gray-white ventrally. The face is mainly black, with blue skin surrounding the eyes. There is a conspicuous white bar (moustache) across the upper lip. There is mild sexual dimorphism in body size. Head and body length: 23 in (58.0 cm) in males and 19.5 in (49.0 cm) in females; tail length: 31 in (78.0 cm) in males and 28 in (69.5 cm) in females. Body mass: 9 lb 8 oz (4.30 kg) for males and 6 lb 6 oz (2.90 kg) for females.

distribution

In equatorial West Africa, between the Sanaga River in southern Cameroon and the lower reaches of the Congo River in Angola.

habitat

Primary and secondary rainforest, gallery forest, and flooded forest.

behavior

Diurnal and essentially arboreal, preferring the middle strata of trees. Forms relatively small one-male groups. Notable for forming mixed species groups (polyspecific associations) with certain other guenons and sometimes mangabeys.

feeding ecology and diet

Diet consists primarily of fruits and seeds, with a complement of animal prey (mainly insects, but also birds' eggs and nestlings).

reproductive biology

Polygamous. Single births are typical. Females do not have sexual swellings. Little-studied in captivity, so gestation period unknown.

conservation status

Not currently regarded as threatened.

significance to humans

Commonly hunted for bushmeat.


Rhesus macaque

Macaca mulatta

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Macaca mulatta (Zimmermann, 1780), Nepal Terai, India. The genus Macaca is the second most species-rich among the cheek-pouched monkeys, with at least 20 species. Within the species Macaca mulatta, six subspecies can be distinguished.

other common names

English: Rhesus monkey; French: Macaque rhésus; German: Rhesusaffe; Spanish: Mono resus.

physical characteristics

Fur medium brown dorsally, with a reddish tone on the hindquarters, and pale brown ventrally. The skin on the face and rump is red and in adult males the scrotum is also red. The tail is relatively short and there is moderate sexual dimorphism in body size. Head and body length: 21 in (53.0 cm) in males and 18 in (45.0 cm) in females; tail length: 10 in (24.5 cm) in males and 9 in (22.0 cm) in females. Body mass: 17 lb (7.70 kg) for males and 11 lb 13 oz (5.35 kg) for females.

distribution

Extremely wide geographical distribution, extending from eastern Afghanistan and northern India in the west to China and southern Vietnam in the east. In India, the southern limit lies some distance south of the River Godavari. The distribution of rhesus monkeys thus includes Afghanistan, Pakistan, India, Nepal, Bhutan, Bangladesh, Myanmar, China, Thailand, Laos, and Vietnam.

habitat

Live in a very wide spectrum of habitats, ranging from semi-desert scrub through dry deciduous and mixed deciduous forests and temperate cedar-oak forests to tropical forest and swamps.

behavior

Diurnal and semi-terrestrial. Typically sleep in trees at night.

feeding ecology and diet

Broad diet includes fruits, seeds, gums, leaves, grasses, roots and invertebrates (mainly insects).

reproductive biology

Polygamous. Single births are typical, although twinning occurs very occasionally. Females have no sexual swelling, but the perineal area shows cylical variation in color, becoming bright red around the time of ovulation. The average length of the ovarian cycle is 29 days and the gestation period is 167 days.

conservation status

Listed as Near Threatened.

significance to humans

Rhesus macaques are protected by local custom in certain parts of their range, for example in much of northern India, and they play an important part in mythology. This species has become the standard laboratory primate for biomedical investigations and has hence been intensively studied in captivity.


Barbary macaque

Macaca sylvanus

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Macaca sylvanus (Linnaeus, 1758), "Barbary Coast," north Africa. This is the only one of 20 species of the genus Macaca that occurs in Africa. All other species are confined to Asia and Southeast Asia.

other common names

English: Barbary ape; French: Magot; German: Berberaffe; Spanish: Mono de Berberea.

physical characteristics

Fur coarse; grayish yellow agouti dorsally and gray-white ventrally. Eyelids pale. Face pink in juveniles but becoming progressively mottled with dark freckles with increasing maturity. There is moderate sexual dimorphism in body size. Head and body length for males: 25.5 in (64.0 cm); tail length: 1 in (2.5 cm). Body mass: 31 lb 15 oz (14.5 kg) for males and 21 1b 13 oz (9.9 kg) for females.

distribution

Originally occurred widely in north Africa and even in southern Europe. Disappeared from Tunisia in relatively recent times and now restricted to isolated forest regions in Algeria and northeastern Morocco. There is a relatively large, artificially provisioned (fed) but otherwise free-ranging colony on Gibraltar.

habitat

Deciduous mixed oak and cedar forests with a pronounced dry season.

behavior

Diurnal and predominantly terrestrial when moving and feeding. Typically sleep in trees at night. Live in moderate-sized multimale social groups that undergo fission when they become too large. Mating is promiscuous and paternity is widespread among group males. Infant carriage by males is particularly prevalent.

feeding ecology and diet

Feed predominantly on the ground but sometimes in trees, eating acorns in addition to cones, needles and bark of cedar trees. Also eat mushrooms and bulbs dug from the ground, along with various invertebrates (particularly insects and scorpions) and occasionally other animal prey.

reproductive biology

Polygamous and promiscuous. Single births are typical, although twinning occurs very occasionally. Females have a prominent sexual swelling, but this is often gray-red rather than bright red when maximally inflated. Gestation period 164 days.

conservation status

Listed as Vulnerable.

significance to humans

Barbary macaques are regarded as pests in Morocco because they eat the growing tips of trees.


Gray-cheeked mangabey

Lophocebus albigena

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Lophocebus albigena (Gray, 1850), Mayombe, Zaire. Traditionally, all mangabeys were included in the genus Cercocebus. However, morphological evidence that was subsequently confirmed by molecular data indicated that there are, in fact, two distinct groups that have independently undergone shortening

of the face, such that a pronounced hollow (fossa) has developed below each eye socket. Predominantly arboreal mangabeys that are more closely allied to baboons are now allocated to the separate genus Lophocebus.

other common names

English: Mantled mangabey; French: Mangabé à gorge blanche; German: Mantelmangabe.

physical characteristics

Long fur, blackish brown dorsally and dark gray ventrally. There is a single or paired tuft of hair on the head and there are long, pale whiskers on the cheeks. A cape of longer hair covers the shoulders, more prominently in males. There is moderate sexual dimorphism in body size. Head and body length: 22.5 in (56.0 cm) for males and 21 in (52.0 cm) for females; tail length: 32 in (80.0 cm) for males and 28.5 in (71.5 cm) for females. Body mass: 18 lb 3 oz (8.25 kg) for males and 13 lb 4 oz (6.00 kg) for females.

distribution

Range extends across tropical Africa from the Cross River in Nigeria eastwards into Uganda and Burundi and southwards to the coast of Gabon and the Alima River in Congo-Brazzaville.

habitat

Primary evergreen tropical rainforest, swamp forest, flooded forest, and semi-deciduous forest in some areas.

behavior

Diurnal and essentially arboreal. Sleeps in trees at night. Lives in multimale groups of moderate size.

feeding ecology and diet

Predominantly eats fruit, but also feeds on animal prey (both invertebrates and vertebrates), leaves, and flowers.

reproductive biology

Polygamous. Single births are typical. Females do not have a sexual swelling. Gestation period 176 days.

conservation status

Not currently regarded as threatened.

significance to humans

Frequently hunted as a source of bushmeat.


Collared mangabey

Cercocebus torquatus

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Cercocebus torquatus (Kerr, 1792), west Africa. All mangabeys were included in the single genus Cercobecus until it was realized that they fall into two distinct groups that have independently undergone facial shortening. Predominantly arboreal mangabeys that are more closely allied to baboons (Papio) are now allocated to the separate genus Lophocebus. More terrestrial mangabeys of the genus Cercobecus are instead related to Mandrillus.

other common names

English: Red-capped mangabey, white-collared mangabey; French: Mangabé à collier blanc; German: Halsbandmangabe; Spanish: Mangabey de collar blanco.

physical characteristics

Fur dark gray dorsally and contrastingly white ventrally. The hair on the crown is dark red, while the chin, cheeks and sides of the neck are white. Eyelids white, contrasting starkly with the black skin of the face. The tail has a distinctive white tip. Sexual dimorphism in body size is pronounced. For males, head and body length is 24 in (60 cm) and tail length is 27.5 in (68.5 cm). Body mass: 20 lb 15 oz (9.50 kg) for males and 12 lb 2 oz (5.50 kg) for females.

distribution

Tropical west Africa, from western Nigeria eastwards through Cameroon and southwards to Río Muni and Gabon.

habitat

Specifically associated with moist forest areas, occurring in primary and secondary swamp, mangrove, and riverine forest.

behavior

Diurnal and largely terrestrial, using vegetation in the understory when in trees. Live in multimale groups of moderate size. Often form mixed groups (polyspecific associations) with various guenon species.

feeding ecology and diet

Fruits, leaves, flowers, and a variety of animal prey.

reproductive biology

Polygamous. Single births are typical. Females have a pronounced sexual swelling. Gestation period 171 days.

conservation status

Listed as Lower Risk/Near Threatened.

significance to humans

Frequently hunted as a source of bushmeat.


Hamadryas baboon

Papio hamadryas

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Papio hamadryas (Linnaeus, 1758), Egypt. There has been considerable discussion about the taxonomy of baboons in the genus Papio because of the existence of hybrid zones between at least some of the main populations. One approach has been to recognize five different species, one being Papio hamadryas and the others being Papio anubis, Papio cynocephalus, Papio papio, and Papio ursinus. At the other extreme, it has been suggested that it would be appropriate to recognize only the single "super-species" Papio hamadryas, as this name has priority, and to regard the five populations as subspecies. Molecular evidence indicates that Papio ursinus and Papio papio, at least, are distinct, and that Papio cynocephalus is probably distinct, whereas the separation between Papio anubis and Papio hamadryas is unclear.

other common names

English: Sacred baboon, mantled baboon; French: Babouin hamadryas; German: Mantelpavian; Spanish: Papión negro.

physical characteristics

There is marked sexual dimorphism in the pelage. In males, the fur is silvery gray dorsally, forming an extensive mane, and pale gray ventrally. Females lack a mane and the fur is olive

brown dorsally and pale gray ventrally. Males have much larger canine teeth than females. There is also pronounced sexual dimorphism in body size. For males, head and body length: 30 in (75.0 cm); tail length: 22 in (55.0 cm). Body mass: 46 lb 5 oz (21.0 kg) for males and 25 lb 2 oz (11.4 kg) for females.

distribution

Distributed on either side of the Red Sea, inhabiting northeastern Somalia, Ethiopia, and a small part of Sudan on the western side and Yemen and part of Saudia Arabia on the eastern side.

habitat

Semi-arid, sparsely wooded savanna, dry short-grass plains and alpine meadows.

behavior

Diurnal and essentially terrestrial, sleeping on steep rock faces at night. Live in large troops in which the basic units are one-male groups (harem groups) and bachelor male groups organized first into clans and then into bands. Unusual among cheek-pouched monkeys in that males remain in their natal clans, whereas females migrate.

feeding ecology and diet

Forage primarily on the ground for grass seed, roots, tubers, and animal prey, including arthropods (particularly termites) and small vertebrates. Also eat leaves.

reproductive biology

Polygamous. Single births are typical. Females have a prominent sexual swelling, which becomes bright red, along with adjacent areas of skin, around the time of ovulation. Gestation period 187 days.

conservation status

Listed as Near Threatened.

significance to humans

Known as the sacred baboon because of its significance in Egyptian mythology.


Gelada

Theropithecus gelada

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Theropithecus gelada (Rüppel, 1835), Semyen (Simien), Ethiopia. This is the only extant species in this genus, but several recent fossil relatives are known, some of them very large-bodied.

other common names

English: Gelada baboon; French: Gelada; German: Dschelada.

physical characteristics

There is marked sexual dimorphism in the pelage. In males, the fur is yellow-brown dorsally, with a long cape of darker hair, and dark grayish brown ventrally. There is a prominent tuft of pale whiskers on each cheek. Females lack a cape and the fur is yellow brown dorsally and dark grayish brown ventrally. The eyelids are very pale, contrasting with the dark facial skin. Males have much larger canine teeth than females. In both sexes, there is a large, hourglass-shaped patch of red skin on the chest. There is also pronounced sexual dimorphism in body size. Head and body length: 28.5 in (71.5 cm) for males and 23 in (57.5 cm) for females; tail length: 19 in (48.0 cm) for males and 15 in (37.0 cm) for females. Body mass: 41 lb 14 oz (19 kg) for males and 25 1b 13 oz (11.7 kg) for females.

distribution

Very limited range in the northern and central highlands of Ethiopia.

habitat

Inhabits montane grassland interspersed with dense thickets, but lacking tall trees and characterized by a pronounced dry season.

behavior

Diurnal and essentially terrestrial. The basic social units are one-male groups and bachelor male groups, which are organized into bands and then into herds that may contain hundreds of members.

feeding ecology and diet

Specialized grass-feeder, foraging by shuffling along on the ischial callosities on the buttocks and plucking grass with the hands. Eats seeds, leaves, and bulbs, along with some animal prey.

reproductive biology

Polygamous. Single births are typical. In females, which lack a sexual swelling in the perineal area, the coloration of the red chest patch changes over the ovarian cycle, reaching maximum intensity around the time of ovulation, when pale, bead-like vesicles bordering the chest patch are also most prominent. Gestation period approximately 170 days.

conservation status

Listed as Near Threatened.

significance to humans

None known.


Mandrill

Mandrillus sphinx

subfamily

Cercopithecinae

tribe

Papionini

taxonomy

Mandrillus sphinx (Linnaeus, 1758), Bitye, Ja River, Cameroon. This is one of only two species in the genus Mandrillus.

other common names

French: Mandrill; German: Mandrill; Spanish: Mandril.

physical characteristics

Body fur is grizzled light brown dorsally and gray-white ventrally. There is pronounced sexual dimorphism in coloration of the face and rump, with males being more brightly colored than females. In males, the nose is bright red and flanked by blue, ridged paranasal bulges along with white whiskers. There is an orange-yellow beard in both sexes, larger in males. In males, the rump is also colored red and blue and the penis is bright red. The coloration of females is similar but less striking. Males also have much larger canine teeth than females. The tail is markedly reduced. There is also a striking degree of sexual di-morphism in body size, with males weighing more that twice as much as females. For females, head and body length: 22 in (54.5 cm); tail length: 3 in (7.5 cm). Body mass: 69 lb 11 oz (31.6 kg) for males and 28 lb 7 oz (12.9 kg) for females.

distribution

Confined to equatorial tropical rainforest of west Africa in southern Cameroon, Río Muni, Gabon, and Congo.

habitat

Primary and secondary evergreen tropical rainforest, gallery forest, and coastal forest.

behavior

Diurnal and semi-arboreal, sleeping in trees at night. Move around in large multimale troops that may be aggregates of individual one-male groups; it has recently been claimed that males are solitary and occupy territories through which females and young move.

feeding ecology and diet

Primarily feeds on fruits and seeds. Also eats leaves, bark, stems, and some animal prey, including both invertebrates (e.g., ants and termites) and vertebrates.

reproductive biology

Polygamous. Single births are typical. Females have small but prominent sexual swellings that are bright red when maximally swollen around the time of ovulation. Gestation period 175 days.

conservation status

Listed as Vulnerable.

significance to humans

Frequently hunted as a source of bushmeat.

Common name / Scientific name / Other common names Physical characteristics Habitat and behavior Distribution Diet Conservation status
Gray-cheeked mangabey Cercocebus albigenaDark pelage and long, ruffled tail. Gray cheeks, long limbs, and long tail. Average body mass 19.8–22 lb (9–10 kg) for males, 14.12–15.4 lb (6.4–7.0 kg) for females.Found in swamp, flooded, and primary evergreen forests, as well as secondary forests with evergreen forests nearby. Species is arboreal, diurnal. Group size is 14 to 17 individuals. Social system is either single male or multi-male.Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon, Uganda, and Zaire.Fruits, mainly figs, and seeds, but also eats leaves, foliage, flowers, and animal prey (arthropods).Not threatened
Sooty mangabey Cercocebus atysDark gray to black pelage, giving sooty or dirty color. Long limbs and tail. Average body mass 18.7 lb (8.5 kg).Found mainly in primary and secondary forests and in flooded, dry, swamp, mangrove, and gallery forests. Species is arboreal and diurnal. Group size can consist of up to 95 individuals. Moves quadrupedally.Sierra Leone to Ghana.Mainly fruits and seeds, but also eats leaves, foliage, flowers, animal prey, and gum.Lower Risk/Near Threatened
Agile mangabey Cercocebus galeritus Spanish: Mangabeye del Río TanaUpperparts are golden brown with black, or dark brown with gold. Underparts are orange or whitish. Long limbs and long tail. Whorl or parting of hair on top of head. Average male body mass 22.5 lb (10.2 kg), female 11.9 lb (5.4 kg).Found mainly in forests that are seasonally flooded, and will also live in open-canopied gallery forests and in areas near rivers. Species is arboreal and diurnal. Group size ranges from 7 to 36 individuals. Moves quadrupedally. Main core of group is adult female and offspring. Social system is led by single male or is multi-male.Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon, and Zaire.Mainly fruits and seeds, but also eats leaves, foliage, flowers, animal prey, and gum.Lower Risk/Near Threatened
Campbell's monkey Cercopithecus campbelli Spanish: Cercopiteco de CampbellColoration on upperparts ranges from greenish gray or black to greenish yellow or buff. Underparts are white or gray. Face is naked. Considerable color variation. Head and body length 12.8–27.6 in (32.5–70 cm), tail length 19.7–39.4 lb (50–100 cm).Found in various habitats, including primary lowland rainforest, secondary forest, riverine forest, and drier woodland. Group size ranges from 8 to 13 individuals. Diurnal species that moves quadrupedally. Very territorial and there are two types of groups; ones with one male and a number of females, and male-only groups.Gambia to Ghana.Mainly fruits, leaves, and gums.Not threatened
Diana monkey Cercopithecus diana Spanish: Cercopiteco dianaPelage is black and surrounded by white beard. Large cheek pouches to carry food while foraging. Average male body mass 11 lb (5 kg), female 8.8 lb (4 kg).Found mainly in primary and. secondary forests in upper canopy. Group size ranges from 14 to 50 individuals. Species is arboreal and diurnal. Moves quadrupedally. Species has unimale social structure.Ghana, Guinea, Ivory Coast, Liberia, and Sierra Leone.Mainly and primarily fruits and seeds, but also eats leaves and arthropods.Endangered
Common name / Scientific name / Other common names Physical characteristics Habitat and behavior Distribution Diet Conservation status
Blue monkey Cercopithecus mitis Spanish: Cercopiteco azulBlue, reddish brown, or grayish brown. Large cheeks. Average male body mass 15.2 lb (6.9 kg), female 9.3 lb (4.2 kg).Found in a variety of habitats, but never very far away from a water source. Group size ranges from 10 to 40 individuals. Species is highly arboreal and diurnal. Moves quadrupedally. Uni-male social system with polygynous mating system.Angola, Burundi, Congo, Ethiopia, Kenya, Malawi, Mozambique, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda,Mainly fruits, but also seeds, arthropods, and leaves.Not threatened
Black mangabey Lophocebus aterrimus German: SchopfmangabenCoarse and glossy black hairs, long brown whiskers, high conical crest. Head and body length 15–35 in (38.2–88.8 cm), tail length 17.1–30.1 in (43.4–76.4 cm), weight 6.6– 26.5 lb (3–12 kg).Found in primary and secondary forests, as well as flooded areas. Species is arboreal and diurnal. Group size ranges from 11 to 20 individuals. Moves quadrupedally. Females form linear hierarchy, main core of groups is females and offspring.Central Zaire.Mainly fruits and seeds, but also eats leaves, foliage, flowers, animal prey, and gum.Lower Risk/Near Threatened
Toque macaque Macaca sinica French: Macaque couronné, macaque toque; Spanish: Macaca de Sri LankaOrange to red, female may have red face. Long limbs and long tail. Average male body mass 12.6 lb (5.7 kg), female 7.9 lb (3.6 kg).Found in a variety of forest types, generally those that are located near water. This species does not live near humans. Average group size is 20.6 individuals. Species is diurnal, travels quadrupedally, has a multimale-multifemale social system. Less dominant individuals are forced to feed in areas with less food.Sri Lanka.Mainly fruits, but also eats flowers, insects, food from crops, and garbage.Vulnerable
Drill Mandrillus leucophaeus Spanish: DrilOlive-green, face and ears are black. Region around anus is colored red, which is more pronounced when excited. Swells exist on sides of nasal area. Infants born with light-colored face that darkens to black at 8 months of age. Average male body mass 44.1 lb (20 kg), female 27.6 lb (12.5 kg).Found in mature primary forests that are lowland, riverine, or coastal. Sometimes also found in secondary forests. On Bioko Island, they can be found in altitudes from sea level to 3,940 ft (1,200 m). Group size ranges from 14 to 200 individuals. Species is diurnal, moves quadrupedally, and has a uni-male social system. Infanticide may occur in the wild.Southeastern Nigeria; Cameroon, north of the Sanaga River and just south of it; and Bioko Island, Equatorial Guinea.Mostly fruits, but also insects, leaves, roots, ground plants, cultivated crops, snails, turtle eggs, and coconuts.Endangered
Guinea baboon Papio papioColoration has red tone to it. Hindquarters lack hair and are red in color. Males have mantle of fur around head. Head and body length 20–45 in (50.8–114.3 cm), tail length 18–28 in (45.6– 71.1 cm).Found in savanna, woodland, steppe, and gallery forests. Group size ranges from 40 to 200 individuals. Species has a multimale-multifemale social system, moves quadrupedally on the ground, is highly competitive (internally), and there is a matrilineal hierarchy.Guinea, Liberia, Mali, Mauritania, Senegal, and Sierra Leone.Mainly fruits, but also flowers, roots, grasses, bark, twigs, sap, tubers, bulbs, mushrooms, lichens, aquatic plants, seeds, shoots, buds, invertebrates, and small vertebrates, such as gazelle.Lower Risk/Near Threatened

Resources

Books

Cords, Marin. "Forest guenons and patas monkeys: male-male competition in one-male groups." In Primate Societies, edited by Barbara B. Smuts, Dorothy Cheney, Robert M. Seyfarth, Richard Wrangham, and Thomas Struhsaker, 98–111. Chicago: Chicago University Press, 1987.

Dunbar, Robin I. M. Reproductive Decisions: An Economic Analysis of Gelada Baboon Social Strategies. Princeton, NJ: Princeton University Press, 1984.

Fa, J. E., and D. G. Lindburg, eds. Evolution and Ecology of Macaque Societies. Cambridge: Cambridge University Press, 1996.

Gautier-Hion, A., Bourliére, F., and J.-P. Gautier, eds. A Primate Radiation: Evolutionary Biology of the African Guenons. Cambridge: Cambridge University Press, 1988.

Groves, Colin P. Primate Taxonomy. Washington, DC: Smithsonian Institute Press, 2001.

Jolly, Clifford J. "Species, subspecies, and baboon systematics." In Species, Species Concepts, and Primate Evolution, edited by W. H. Kimbel, and L. B. Martin, 67–107. New York: Plenum Press, 1993.

Kingdon, J. The Kingdon Field Guide to African Mammals. London: Academic Press, 1997.

Kummer, H. Social Organization of Hamadryas Baboons. Chicago: University of Chicago Press, 1968.

Loy, J. "The sexual behavior of African monkeys and the question of estrus." In Comparative Behavior of African Monkeys, edited by E. Zucker, 175–195. New York: Alan Liss, 1987.

Murray, P. "The role of cheek pouches in cercopithecine monkey adaptive strategy." In Primate Functional Morphology and Evolution, edited by R. H. Tuttle, 151–194. The Hague: Mouton, 1975.

Napier, J. R., and P. H. Napier, eds. Old World Monkeys. New York: Academic Press, 1970.

Napier, P. H. Catalogue of Primates in the British Museum (Natural History) and Elsewhere in the British Isles. Part II: Family Cercopithecidae, Subfamily Cercopithecinae. London: British Museum (Natural History), 1981.

Wolfheim, Jaclyn H. Primates of the World: Distribution, Abundance, and Conservation. Seattle: University of Washington Press, 1983.

Periodicals

Benefit, Brenda R. "Victoriapithecus: The key to Old World monkey and catarrhine origins." Evolutionary Anthropology 7 (1999): 155–174.

Delson, E., Terranova, C. J., Jungers, W. L., Sargis, E. J., Jablonski, N. G. and P. C. Dechow. "Body mass in Cercopithecidae (Primates, Mammalia): Estimation and scaling in extinct and extant taxa." Anthropological Papuan American Museum of Natural History 83 (2000): 1–159.

Disotell, T. R. "Generic level relationships of the Papionini (Cercopithecoidea)." American Journal of Physical Anthropology 94 (1994): 47–58.

——. "The phylogeny of the Old World monkeys." Evolutionary Anthropology 5 (1996): 18–24.

Fleagle, J. G., and W. S. McGraw. "Skeletal and dental morphology supports diphyletic origin of baboons and mandrills." Proceedings of the National Academy of Sciences, USA 96 (1999): 1157–1161.

Fooden, J. "Provisional classification and key to the living species of macaques (Primates: Macaca)." Folia Primatologica 25 (1976): 225–236.

Gautier-Hion, A. "Social organization of a band of talapoins (Miopithecus talapoin) in northeastern Gabon." Folia Primatologica 12 (1970): 116–141.

Groves, C. P. "Phylogenetic and population systematics of the mangabeys (Primates, Cercopithecoidea)." Primates 19 (1978): 1–34.

Grubb, P. "Distribution, divergence and speciation of the drill and mandrill." Folia Primatologica 20 (1973): 161–177.

Harris, E. E., and T. R. Disotell. "Nuclear gene trees and the phylogenetic relationships of the mangabeys (Primates: Papionini)." Molecular Biology Evolution 15 (1998): 892–900.

Isbell, L. A. "Diet for a small primate: Insectivory and gummivory in the (large) patas monkey (Erythrocebus patas pyrrhonotus)." Americam Journal of Primatology 45 (1998): 381–398.

Kingdon, J. "Role of visual signals and face patterns in African forest monkeys (guenons) of the genus Cercopithecus." Transactions of the Zoological Society, London 35 (1980): 425–475.

Loy, J. "The reproductive and heterosexual behaviours of adult patas monkeys in captivity." Animal Behavior 29 (1981): 714–726.

Loy, J., M. Head, and K. Loy. "Reproductive cycles of captive patas monkeys." Laboratory Primate Newsletter 17 (1978): 9–12.

Morales, J. C., and D. J. Melnick. "Phylogenetic relationships of the macaques (Cercopithecidae: Macaca), as revealed by high resolution restriction site mapping of mitochondrial ribosomal genes." Journal of Human Evolution 34 (1998): 1–23.

Rowell, T. E. "Social organization of wild talapoin monkeys." American Journal of Physical Anthropology 38 (1973): 593–597.

Smith, R. J., and W. L. Jungers. "Body mass in comparative primatology." Journal of Human Evolution 32 (1997): 523–559.

Strasser, E., and E. Delson. "Cladistic analysis of cercopithecid relationships." Journal of Human Evolution 16 (1987): 18–99.

Takenaka, O., M. Hotta, Y. Kawamoto, and E. Brotoisworo. "Origin and evolution of Sulawesi macaques: 2. Complete amino acid sequences of seven chains of three molecular types." Primates 28 (1987): 99–109.

van der Kuyl, A. C., C. L. Kuiken, J. T. Dekker, and J. Goudsmit. "Phylogeny of African monkeys based on the mitochondrial 12S rRNA gene." Journal of Molecular Evolution 40 (1995): 173–180.

Vilensky, J. A. "The function of ischial callosities." Primates 19 (1978): 363–369.

Washburn, S. L. "Ischial callosities as sleeping adaptations." American Journal of Physical Anthropology 15 (1957): 269–280.

Robert D. Martin, PhD