Papio papio

Geographic Range

Papio papio is found in a small portion of western equatorial Africa. These animals are found in parts of Guinea, Guinea-Bissau, and Senegal, with some popuations known in Mauretania and Mali.

This species is part of a complex of closely related African baboon species. We have an account of the whole genus under Papio .

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

There are few reports regarding the habitat of this species. Guinea baboons have only been studied extensively in one location, the Parc National du Niokolo-Koba in eastern Senegal. This park is located at the border of Sudan-type savanna and Guinea-type savanna.

The Mont Assirik area of the Parc, where P. papio has been studied, is topographically complex. Steep sided valleys radiate from Mont Assirik. Thin stripss of gallery forest are found along the seasonal watercourses, but comprize less than 5% of the available habitat. There are some permanent water pools located deep in these valleys.

In addition to gallery forest, vegetative cover in the area includes both deciduous woodland and bamboo (42%), with the remainder of the land covered by non-wood vegetation. These non-wooded areas vary seasonally, sometimes having very tall grasses, and at other times of the year being burned to the ground, creating very bare, open habitat.

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest
• rainforest rainforest

• Other Habitat Features
• agricultural agricultural

Physical Description

Guinea baboons are considered small among their congeners. Although measurements for this species are not reported, they can be assumed to be on the small end of those reported by Nowak (1999) for all non-hamadryas baboons. For these, head and body length ranges between 508 and 1,143 mm, with the tail adding an additional 456 to 711 mm to the total length. Weights range between 13 and 26 kg, with males significantly larger and heavier than females.

The pelage of P. papio is a reddish brown, with significant geographic variation. Those animals in the western portion of the range are lighter and more strikingly red than those found in the eastern portion of the range, where animals are darker and more brownish. Unlike many baboon species, P. papio characteristically display the same color pelage on back, arms, cheeks and abdomen. Individual hairs have multiple bands of color, and are wavey in texture. In other species of Papio , the youngest animals display a charateristic natal pelage, which differs from adult pelage in color and texture. Although the natal pelage of P. papio has not been reported, it can be assumed that infants display some differences from adults.

Like anubis and hamadryas baboons, Guinea baboon males have a mane, although the mane in this species is not as pronounced as it is in hamadryas baboon males.

The facial skin of P. papio is purple-black. The moderate amount of unfurred skin visible around the anal area of males is pinkish in color. The female ano-genital skin changes color depending upon reproductive condition and age, as detailed in the reproductive section of this account.

Papio papio has a medium-sized skull for the genus, and a normal facial orientation. The long face has a prominent muzzel. Adults have 32 teeth. Canine teeth are large, especially in males, and the first lower premolar has been modified to serve as a hone for the upper canine. The large molars are strongly bilophidont.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• ornamentation ornamentation

Reproduction

P. papio is the most poorly known of all the Papio species. Perhaps because the habitat of Guinea baboons allows poor visibility, much is unknown about these monkeys.

The social organization of P. papio appears to be multi-leveled, much like that of hamadryas baboons. The basic unit of social organization is the OMU, or One Male Unit, comprized of a single adult male, adult females, juveniles, and sometimes subadult males. These OMUs may aggregate into higher order associations for travel through areas where there is a high risk of predation, and at sleeping sites. Unlike males of P. hamadryas , male Guinea baboons do not aggressively "herd" their females, although males do control the movements of the groups.

Although it has been proposed that adult males may be able to restrict the sexual access which other males have to females in their OMUs, multiple males, both adult and subadult, have been observed to mate with the same female. In these observations, adult males were reported to be uncompetitive and apparently tolerant of one another.

If such noncompetitive, polygynadrous mating is the rule in this species, P. papio would be an outlier within the genus. Most baboons can be characterized as exhibiting a great deal of intermale competition for access to reproductive females. In other baboons, this competition results either in the formation of single male harem units, as is the case with hamadryas baboons, or temporary consortships between males and estrous females, during which the male maintains exclusive reproductive access to the female, as commonly seen in the other species of baboons.

It should be noted that the observations of Guinea baboons mating occurred while the baboons were in their sleeping trees (Dunbar and Nathan, 1972). These trees tend to be very tall, and, as there is a real risk of dying as a result of a fall, it may be that the location of the observed copulations, rather than the especial tolerance of the males, may be responsible for the lack of competition seen between males in that study. Further, it is not clear from the reports of these matings whether the males who mated with the same female belonged to the same OMU. There are no data available regarding the extent to which sexual access to females may be restricted by the males or by the females themselves, as they approach ovulation. Further research on the mating behavior of P. papio would help to clarify the reproductive significance of the OMU.

Paucity of data regarding long-term relationships between individually identified Guinea baboons prevents speculation on how males or females choose their mates. In other species of baboons, subgroups within a troop are often formed for reproductive purposes, such as the OMUs seen in hamadryas baboons, or the consortships seen in anubis, yellow, and chacma baboons. If the OMU of Guinea baboons have reproductive significance, as is likely, it is not known what criteria females may use in joining one male versus another.

• Mating System
• polygynous polygynous
• polygynandrous (promiscuous) polygynandrous (promiscuous)

There is virtually no information available for reproduction in this species. Harvey, Martin, and Clutton-Brock (1987) report that the gestation period for Guinea baboons is 184 days, and the interbirth interval is 423 days.

In captivity, females experience the first swelling of their sexual skin at a mean age of 3.8 years. The sexual swelling lasts for an average of 13.2 days. The female cycle length is 29.3 days. First pregnancy occurs at the mean age of 4.3 years. The timing of such events is typically accelerated in captive animals compared to their wild counterparts. There are no data available on the timing of reproductive maturity in males of this species, although in other baboons, males reach reproductive maturity around 60 to 74 months of age.

Females apparently advertize their sexual condition through changes in the color and shape of the skin surrounding the ano-genital region. The pink skin of the ano-genital region becomes swollen and rounded as the female approaches ovulation. This swelling typically lasts about 13.2 days. During the rest of the cycle, the skin in the ano-genital area is flat with a wrinked texture.

The skin surrounding the ischial callosities is black in young females, but during pregnancy can undergo rapid changes in color (termed a "color waltz") before settling into a permanent dark pink color. Older females tend to show a less pronounced "color waltz" at the beginning of pregnancy, and are more likely to have pink or dark pink skin surrounding their ischial callosities at times other than during pregnancy.

Although no data are available for P. papio , anubis baboons ( P. anubis ) wean their young around 420 days of age. Young of other baboon species become independent sometime after weaning, although the mother may continue to carry, groom, and otherwise help her offspring after that time. It is reasonable to assume that the same is true of Guinea baboons.

In other species of baboons, there are specific patterns of dispersal of males and females which are important in structuring the social system. For example, in hamadryas baboons, females leave their natal groups and each becomes part of a social unit controlled by a single adult male. In yellow and olive baboons, females remain in their natal groups for life and maintain long-term bonds with their female kin. The social stucture of the group revolves around the kin relationships of the females, with particular matrilines holding stable positions in a dominance heirarchy. In these species, male baboons emigrate into new social groups, and must establish themselves in the dominance heriarchy of those groups.

It is not known whether P. papio is a male-transfer or a female-transfer species, just as it is not known whether there is a stable female core to Guinea baboon OMUs. The stability of OMUs through time has not been examined, and the kin relationships between males whose OMUs associate with one another are not known. Further research on the emigration patterns of these baboons would help to clarify a great deal about the social structure and reproductive behavior of this species.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous

Little is known about the parental care exhibited by this species. However, in other baboons, the mother performs the bulk of parental care. This parental care is substantial, as the young baboon cannot walk or climb on its own. The mother grooms her offspring, carries it, and provides it with nourishing milk. The age of weaning for P. anubis is around 420 days, and it is likely that P. papio is similar.

In other baboon species, males play some role in parental care. In hamadryas baboons, where only one male mates with the females in the social group, the father sometimes holds, carries, or shares meat with his offspring. In other species of baboon, males respond to some infants within the troop in a similar fashion. These infants are usually the offspring of females with whom the male has a long-term friendship, and are therefore likely to be be the offspring of the male. Adult males and infants in P. papio have been observed to associate with one another, with the OMU leader sometimes carrying and grooming the infants and juveniles of his OMU. It is not known at this time whether the OMU leader is the likely father of these offspring.

Because the social system of these animals is still poorly understood, it is not known whether animals continue to associate with parents of either sex after independence. In P. hamadryas , adult male relatives have life-long associations. In P. anubis , P. cynocephalus , and P. ursinus , females are known to interact with their female kin throughout their lives. In these latter species, females inherit a dominance rank immediately below that of their mother. Further research on the social structure of P. papio will allow assessment of the inheritance of rank in this species, and help to clarify questions regarding the extent of parental care in this species.

• Parental Investment
• altricial altricial
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • male
    • female
• extended period of juvenile learning

Lifespan/Longevity

The lifespan for P. papio is not known. However, P. hamadryas has an average lifespan around 35 years, and a maximum measured lifespan in captivity of 45 years. It is likely that Guinea baboons are similar.

Behavior

Papio papio is a diurnal, mainly terrestrial, quadrupedal primate. While walking, these animals carry their weight on the underside of their fingers in the front, and along the entire sole of their feet in the back. They climb with agility, and are generally found sleeping in very large trees at night.

The social structure of Guinea baboons is apparently multi-leveled, like that of Hamadryas baboons. Adult males maintain separate social units, or OMUs, containing females, juveniles, and subadult males. These OMUs aggregate into larger associations during times of high predation risk. Subgroups of baboons are clearly visible in such aggregations, and will often take turns when using a watering hole.

Although adult male Guinea baboons do not aggressively herd females, as do Hamadryas baboons, they control the movements of their groups using a combination of corralling, running to speed the progression, as well as shaking, jumping, and prancing to change direction.

Within a troop of Guinea baboons, OMU subgroups form during the context of daily marches and can be distinguished from one another at sleeping sites. These OMUs can coalesce during the day, and may splinter off again. The stability of higher levels of association in this species are not well undeerstood, nor is membership in an OMU over ime. Interestingly, subgroups which have spent the night in separate sleeping sites sometimes coalesce in P. papio . This indicates either that sleeping arrangements are more variable than found in other species of baboons, where an entire troop sleeps in the same location, or that the social structure may be somewhat more fluid than that of other species, allowing non-agonistic contact between troops.

Sleeping sites are very important limiting factors in the distribution and travel of baboons. Guinea baboons bed down mainly in large kapok or palm trees. Some of the trees used are so large that the baboons cannot climb the trunks of these trees, and must access them solely by leaping from cliffs or nearby trees. This behavior is apparently dangerous, and there is some risk of falling. Juvenile animals are known to scream in apparent fear when approaching a leaping point, sometimes "chickening out" before they can make the jump.

Within sleeping trees, a single OMU will usually occupy a particular branch of the tree. Rather than bracing themselves against the trunk of the tree to stabilize themselves while sleeping, as one might expect, Guinea baboons tend to sleep as far from the tree trunk as possible. Sometimes animals situate themselves quite far out on the ends of branches. Females and young tend to sleep further out on branches than to adult males. This may represent a proctective tendency of males, blocking the route of potential predators, such as leopards, to the more vulnerable females and young. It may represent a means by which a male controls sexual access to a female during the night, limiting other males from approaching her. However, it is just as likely that the positioning of males closer to the tree trunk is merely a function of the greater weight of males. The weaker branches farther from the tree trunk may not be adequate to support their bulk.

The composition of Guinea baboon sleeping parties may vary seasonally, with a greater proportion of the groups being juveniles during the wet season. Adult females are the most stable age/sex class in sleeping aggregations.

Guinea baboons become active before dawn, beginning the day with urination and defecation. Juvenines are the first to become active, and adult males the last. In the dry season, when the sun rises later, the baboons tend to leave their sleeping trees earlier. Once animals begin to leave the tree, others quickly follow, with all members of the sleeping party emptying onto the ground over the course of several minutes.

After leaving their sleeping sites, Guinea baboons begin their daily foraging march. During foraging, the baboons may splinter off into smaller parties. Vocalizations allow parties to stay in contact with one another, even though the baboons are out of visual contact. Movements are apparently coordinated through these vocalizations, allowing the subgroups of baboons to reconvene, often before the baboons march across an open, and presumably dangerous, area.

Although little is known about the social relationships of these animals in the wild, some captive studies indicate that the relationships between male baboons can be quite strong, and can involve a lot of trust. For example, adult males are known to expose their genitals to one another and may grasp the genitals of other males as a part of greetings designed to convey information about their willingness to cooperate with one another. Given the potential damage to the genitals which a rival could cause during such a greeting, a strong bond is apparently a necessity for such liberties to be taken. Those males with close relationships are much more inclined to share such greetings than are mere acquaintences. Such trust and cooperation between males may be necessary to permit the association of OMUs.

Researchers have recently discovered that Guinea baboons use caves. Unlike Chacma baboons ( P. ursinus ) which sometimes sleep in caves, P. papio appears to enter caves in order to lick the walls. This geophagy may be a way that the animals can obtain essential salts. An entire foraging troop has been seen exiting a cave together, indicating that cave use may be a group affair, rather than the behavior of just a few individuals at a time.

• Key Behaviors
• arboreal arboreal
• terricolous
• diurnal diurnal
• motile motile
• nomadic nomadic
• sedentary sedentary
• social social
• dominance hierarchies dominance hierarchies

Home Range

The home range size for this baboon species is not known.

Communication and Perception

Guinea baboons are highly communicative animals. They communicate with one another using a variety of vocalizations and physcial interactions. In addition to vocalizations to one another, these animals have vocal communications apparently intended to be received and interpreted by predators.

In Senegal, Guinea baboons are especially vocal. Their high rate of calling provides researchers with an excellent opportunity to test the function of various vocalizations.

Among the vocalizations made by P. papio are several loud calls, which can be heard at great distance, as well as some softer calls, generally used in more intimate contexts. What follows is a summary of different types of calls and the animals within the troop who make them.

All age and sex classes except infants give a loud call known as a wahoo bark. Adult males have a sterotyped version of this call, sometimes called a Type 2 loud call. In addition to this loud call, there are sharp barks--explosive single phrased calls given by all individuals except infants. Adult males are known to make Type 1 loud calls, or roar-grunts. These consist of a low hum, followed by a series of loud, deep grunts, which become lower in pitch and further apart as the series of grunts progresses.

In addition to loud calls, Guinea baboons are known to make several types of grunting vocalizations. Deep grunts, which are apparently given only by adult males, are long, low grunts, which have fluctuating pitch and volume. Rapid grunts, given by all animals except infants, are a quick, continuous series of grunts. Two-phase grunts are produced on both inhalation and exhalation. Two-phased grunts are loud, and are made in a rapid series by all animals except infants. Finally, copulation grunts are given by estrus females after copulation. These vocalizations consist of a loud grunt followed by a series of more quiet grunts.

A vocalization called a geck is given by all age and sex classes, including infants. Gecks are brief, sharp vocalizations which are given either in a rapid series or singly. Infants make a sheeplike moan, starting low and rising in pitch.

The fuctions of these calls has been analyzed by examining the context and habitats in which they are given. Three main sorts of contexts of calling are evident for Guinea baboons: Nocturnal volleys, intergroup coordination, and agonistic disturbances.

During the night, nocturnal volleys of adult male loud calls are apparently provoked by the sounds of predators such as lions, leopards, and hyaenas, or by the sound of other baboon groups making such nocturnal calls. Chains of volleys ring through the forest, in an apparent chain reaction to an initial stimulus. These volleys include type 1 and type 2 loud calls. The baboons making the calls do not move from their sleeping sites.

One possible function for nocturnal volleys is that the calls are designed to advertize to predators the number of adult male baboons present in a sleeping site, possibly indicating the strength of the defense against a predator which the group could muster. However, in one observation a lion approached a Guinea baboon sleeping site, passing directly below the tree where the baboons were reposing. As the lion approached, the volley of calls gradually decreased until the baboons were silent. The calls increased again as the lion moved away. This may indicate either that the baboons were too afraid to keep up their calls when in close proximity to the predator, or that the strategy of deterence had failed, and so the baboons were reduced to a secondary strategy of remaining cryptic, hoping the predator would pass them by.

Vocalizations are also used in coordinating group movements. Double-phase barks, type 2 loud calls, and single phase barks all increased in frequency when a group was undergoing fission, fusion, or passing by another group. Such increased calling rates may help baboons to avoid separation in thick vegetation. When separated, peaks of barking may help the animals maintain contact so that subgroups can rejoin one another.

Because of the high density of baboons in the area of study near Mont Assirik, groups of baboons frequently encounter one another during the course of the day. Sometimes these groups will fuse. Groups known to have slept in different locations are known to occasionally fuse, and so calls may be an important means by which different groups identify one another.

Papio papio tends to feed in small groups of 5 to 10 animals while using areas of tall grass. In other habitats, baboons typically take pains to maintain much larger group sizes. When the baboons are done using tall grass habitat, the foraging parties regroup efficiently, using bark calls to coordinate the reunion.

The final major context of calls is during agonistic disturbances. During intragroup agonism, wahoo and sharp barks cluster with screams and gecks. These latter calls are associated with submission and fear. Rapid grunting is also common in this context, and may be associated with branch-shaking displays, attacks, and threats. Roargrunts, or type 1 loud calls, are often given after aggression.

In addition to this impressive array of vocal communications, P. papio exhibits tactile communication. Grooming is common in all primates, and is an apparent indicator of social bonds between individuals. Various forms of touching are also important in greetings, with mounting, presenting of the rump, and even touching of the genitals sometimes plays a role. The intensity of these greetings is associated with the bond between individuals.

Although not reported for Guinea baboons, some chemical communication is known to occur in other species of Papio . Female baboons are known to produce aliphatic acids when they are in estrous, apparently enhancing their sexual attractiveness to males. It is possible that Guinea baboon females produce similar scent cues.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Baboons are omnivorous primates, subsisting often on roots, tubers, bulbs and corms of grasses. They will eat meat when it is available.

In a study of captive animals, various fruits were presented to a Guinea baboon, and the portion of the fruit eaten was recorded. The animal was most inclined to eat the seeds of these fruits, although other portions of fruits, such as the pericarp and the flesh, were also consumed.

When processing seeds to eat, the Guinea baboon and other Cercopithecine monkeys tested used their molars to puncture and then to crush the seeds. Researchers think that this may indicate that the strongly bilophodont molars of cercopithecine primates may be an adaptation to seed predation.

• Primary Diet
• omnivore omnivore

• Animal Foods
• birds
• mammals
• eggs
• insects

• Plant Foods
• leaves
• roots and tubers
• seeds, grains, and nuts
• fruit
• flowers

Predation

Specific details on predation of Guinea baboons are not available. However, large African carnivores, such as African wild dogs, lions, leopards, and hyaenas are sympatric. These are presumed to prey upon the baboons.

Guinea baboons appear to have two strategies to avoid predation. When presumed predators are noted at night, adult male baboons will begin to call in protracted nocturnal volleys. These calls may alert the predators to the presence of the adult males, thereby warning them from a risky attack on a sleeping group of baboons. When predators are very close, the baboons appear to rely on crypsis, becoming nearly silent until the predator has passed the sleeping site.

In addition to their vocalizations toward predators, Guinea baboons are known to sleep in very large trees, which might be difficult for predators to access. Indeed, the baboons themselves have some difficulty reaching their sleeping sites, often propelling themselves into the crown of the sleeping tree from the branches of smaller trees. Use of such sleeping sites itself could be considered a behavior which thwarts predators.

Ecosystem Roles

Guinea baboons probably play a role in soil aeration through the digging of corms, roots, and tubers. They are likely to disperse the seeds of the fruits and grains that they eat. Baboons provide food for their predators, may impact populations of small animals on which they sometimes feed.

• Ecosystem Impact
• disperses seeds
• soil aeration soil aeration

Economic Importance for Humans: Positive

Baboons are used extensively in medical and behavioral research. In addition, they are often housed in zoos, allowing many people to be entertained by their antics.

• Positive Impacts
• ecotourism ecotourism
• research and education

Economic Importance for Humans: Negative

Guinea baboons are known to harbor the trematodes which cause schistisomiasis in humans. Although nothing has been specifically reported for Guinea baboons, other species of baboons are known to raid crops. Baboons are large animals, and they are known to bite to defend themselves if cornered.

• Negative Impacts
• injures humans
  • bites or stings
  • carries human disease
• crop pest

Conservation Status

IUCN lists Guinea baboons as lower risk/near threatened. Other agencies do no list this species. It is possible that taxonomic difficulties within the genus Papio are responsible for the failure of other agencies to list these baboons.

Other Comments

Although most people probably don't like to think about it, baboons provide important habitat to various parasites for whom they serve as hosts. McGrew et al., 1989, examined the intestinal parasites found in Guinea baboons of Mont Assirik. They found nematodes, trematodes, and protozoans infesting P. papio . Details on rates of infection within the population are given below. It is not know what cost to the health of the baboons such parasite infestation imposes.

The nematodes found in Guinea baboons included Strongyloides sp., Physaloptera sp., Trichuris sp., Streptophargus sp., and Necator sp. Each of these parasites was present in between 26 and 38 per cent of the animals assessed.

McGrew et al. found Schistosoma mansoni , and Stingeodea sp. in 23 and 44 per cent of the populations, respectively. These trematodes are important disease agents. This may be the first report of S. mansoni in free living Guinea baboons, in which the life cycle and transmission of the parasite occurs independently of humans. Interestingly, the baboons apparently show several unique behaviors which would help then to avoid infecion by the water-borne S. mansoni . For example, they drink in shorter bouts than is normally seen in baboons, and they use non-flowing water sources rather than flowing water sources.

Finally, the population of Guinea baboons near Mont Assirik showed a high level of infection with protozoans. Balantidium coli , Iodamoeba buetschlii and Endamoeba coli were found in 72, 38, and 87 per cent of individuals sampled.

Additional Links

Encyclopedia of Life

Contributors

Nancy Shefferly (author), Animal Diversity Web.

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